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  • 1.
    Alexandersson, Martin
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department. Chalmers University of Technology, Sweden.
    Kjellberg, Martin
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Mao, W.
    Chalmers University of Technology, Sweden.
    Ringsberg, Jonas W
    Chalmers University of Technology, Sweden.
    Prediction of roll motion using fully nonlinear potential flow and ikeda’s method2021In: Proceedings of the International Offshore and Polar Engineering Conference, International Society of Offshore and Polar Engineers , 2021, p. 1670-1679Conference paper (Refereed)
    Abstract [en]

    Getting the best possible accuracy with the lowest possible computational cost is an important factor in the early design stage of ships. Potential flow-based analysis presents such a solution for seakeeping analyses. The accuracy of roll motion in potential flow is however not so good, due to the large influence from vicsous roll damping, which is missing in these calculations. This paper proposes a hybrid method, as a solution to this problem, where the viscous roll damping from Ikeda’s semi-empirical method is injected into an existing 3D unsteady fully nonlinear potential flow (FNPF) method. The hybrid method is investigated using roll decay tests with the KVLCC2 test case. This investigation shows that the accuracy of simulated roll motions is significantly improved and also shows good agreement with the corresponding roll decay model tests.

  • 2.
    Alexandersson, Martin
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department. Chalmers University of Technology, Sweden.
    Mao, Wengang
    Chalmers University of Technology, Sweden.
    Ringsberg, Jonas W
    Chalmers University of Technology, Sweden.
    Analysis of roll damping model scale data2021In: Ships and Offshore Structures, ISSN 1744-5302, E-ISSN 1754-212X, Vol. 16, no S1, p. 85-92Article in journal (Refereed)
    Abstract [en]

    Having an accurate prediction of ship roll damping is crucial when analysing roll motions. In this paper, the simplified Ikeda method (SI-method) is compared with the original Ikeda method. The methods are compared using results from a database of roll decay tests carried out on modern merchant ships and a smaller set of predictions in which the original Ikeda method was used. It was found that most of the ships in the database had dimensions outside the limits of the SI-method. Thus, the SI-method showed poor agreement with model tests outside its limits but acceptable agreement for ships within limits. It was found that the deviations were caused by extrapolation errors of the wave-damping in the SI-method. Two ways to improve the accuracy of the SI-method were proposed based on regression, which gave about the same accuracy as the original Ikeda method. © 2021 The Author(s).

  • 3.
    Alexandersson, Martin
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department. Chalmers University of Technology, Sweden.
    Mao, Wengang
    Chalmers University of Technology, Sweden.
    Ringsberg, Jonas W
    Chalmers University of Technology, Sweden.
    System identification of Vessel Manoeuvring Models2022In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 266, article id 112940Article in journal (Refereed)
    Abstract [en]

    Identifying the ship's maneuvering dynamics can build models for ship maneuverability predictions with a wide range of useful applications. A majority of the publications in this field are based on simulated data. In this paper model test data is used. The identification process can be decomposed into finding a suitable manoeuvring model for the hydrodynamic forces and to correctly handle errors from the measurement noise. A parameter estimation is proposed to identify the hydrodynamic derivatives. The most suitable manoeuvring model is found using the parameter estimation with cross-validation on a set of competing manoeuvring models. The parameter estimation uses inverse dynamics regression and Extended Kalman filter (EKF) with a Rauch Tung Striebel (RTS) smoother. Two case study vessels, wPCC and KVLCC2, with very different maneuverability characteristics are used to demonstrate and validate the proposed method. Turning circle predictions with the robust manoeuvring models, trained on zigzag model tests, show good agreement with the corresponding model test results for both ships. © 2022 The Author(s)

  • 4.
    Alexandersson, Martin
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department. Chalmers University of Technology, Sweden.
    Zhang, Daiyong
    Chalmers University of Technology, Sweden.
    Mao, Wengang
    Chalmers University of Technology, Sweden.
    Ringsberg, Jonas W
    Chalmers University of Technology, Sweden.
    A comparison of ship manoeuvrability models to approximate ship navigation trajectories2023In: Ships and Offshore Structures, ISSN 1744-5302, E-ISSN 1754-212X, Vol. 18, no 4, p. 550-557Article in journal (Refereed)
    Abstract [en]

    It is essential to describe a ship’s manoeuvrability for various applications, e.g. optimal control of unmanned surface vehicles (USVs). In this study, the capability of two recognised manoeuvrability models to predict ships’ trajectories is investigated based on both simulation and open-water experiment test data. The parameters of these models are estimated by a statistical learning method. The goodness of the two estimated models for describing a merchant ship’s manoeuvrability is first studied using her manoeuvring simulation data. Then, experimental manoeuvring tests to use a USV in open water with wind and drifting effects are used to check the conventional model identification procedures. Finally, some modifications and adjustments are proposed to improve the conventional procedures. It shows that the proposed procedures can accurately derive the ship’s manoeuvrability based on experimental data. © 2022 The Author(s). 

  • 5.
    Altuntas Vural, Ceren
    et al.
    Chalmers University of Technology, Sweden.
    Gonzalez-Aregall, Marta
    University of Gothenburg, Sweden.
    Woxenius, Johan
    University of Gothenburg, Sweden.
    Rogerson, Sara
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Svanberg, Martin
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    International container shipping through the Covid-19 pandemic - Disruptions from a Swedish perspective2024Report (Other academic)
    Abstract [en]

    At the onset of the pandemic in spring 2020, the Swedish shipping sector was first affected by border closures preventing passengers to use RoPax shipping and cruise ferries. There were some blank sailings but in general they kept operating to foster intra-European trade by trucks despite the missing revenues from passengers. Shipping in general was affected by port disrup-tions and complicated crew changes. Eventually, however, it was clear that the most dramatic disruptions on a global scale where experienced in the container segment. General media reported on delayed goods, high freight rates and, however not related to the pandemic, the Ever Given blocking the Suez Canal for a week in March 2021. Currently, there are few reports of supply chains and shipping suffering from disruptions and capacity constraints related to the pandemic. The peak in freight rates was rather replaced by depressed rates and there is a certain risk that some logisticians and supply chain managers regard the pandemic as a once-in-a-lifetime event and just want to get back to a previous be-haviour seeing container shipping as a commodity with indefinite capacity at a reasonable price. Nevertheless, the war in Ukraine, the drought in the Panama Canal and the attacks by the Houthi rebels in the Red Sea create other problems for container shipping. Freight rates increase significantly, but from very low levels. The purpose of the report is to describe and analyse how international container shipping was affected by the Covid-19 pandemic and other disruptions. The analysis takes a Swedish perspective on disruptions and tries to go beyond the anecdotal reporting and capture what happened and why. Container shipping is put into a context of economy, consumption, world trade, supply chains and logistics. The pandemic and more current events affecting container shipping market are described together with how shipping lines responded. A series of interviews with Swedish actors revealed how they perceived the disruptions and what countermeasures the actors have applied to mitigate the effects, their organisational learning and how they prepare for future disruptions

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  • 6.
    Andersson, Jennie
    et al.
    Chalmers University of Technology, Sweden.
    Shiri, Alex
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Bensow, Rickard
    Chalmers University of Technology, Sweden.
    Yixing, Jin
    China Ship Scientific Research Center, China.
    Chengsheng, Wu
    China Ship Scientific Research Center, China.
    Gengyao, Qiu
    China Ship Scientific Research Center, China.
    Deng, Ganbo
    Ecole Centrale de Nantes, France.
    Queutey, Patrick
    Ecole Centrale de Nantes, France.
    Xing-Kaeding, Yan
    Hamburg Ship Model Basin, Germany.
    Horn, Peter
    Hamburg Ship Model Basin, Germany.
    Lücke, Thomas
    Hamburg Ship Model Basin, Germany.
    Kobayashi, Hiroshi
    National Maritime Research Institute, Japan.
    Ohashi, Kunihide
    National Maritime Research Institute, Japan.
    Sakamoto, Nobuaki
    National Maritime Research Institute, Japan.
    Yang, Fan
    Shanghai Ship and Shipping Research Institute, Chia.
    Gao, Yuling
    Shanghai Ship and Shipping Research Institute, China.
    Windén, Björn
    SHORTCUt CFD, USA.
    Meyerson, Max
    University of Michigan, USA.
    Maki, Kevin
    University of Michigan, USA.
    Turnock, Stephen
    University of Southampton, UK.
    Hudson, Dominic
    University of Southampton, UK.
    Banks, Joseph
    University of Southampton, UK.
    Terziev, Momchil
    University of Strathclyde, UK.
    Tezdogan, Tahsin
    University of Strathclyde, UK.
    Vesting, Florian
    Volupe AB, Sweden.
    Hino, Takanori
    Yokohama National University, Japan.
    Werner, Sofia
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Ship-scale CFD benchmark study of a pre-swirl duct on KVLCC22022In: Applied Ocean Research, ISSN 0141-1187, E-ISSN 1879-1549, Vol. 123, article id 103134Article in journal (Refereed)
    Abstract [en]

    Installing an energy saving device such as a pre-swirl duct (PSD) is a major investment for a ship owner and prior to an order a reliable prediction of the energy savings is required. Currently there is no standard for how such a prediction is to be carried out, possible alternatives are both model-scale tests in towing tanks with associated scaling procedures, as well as methods based on computational fluid dynamics (CFD). This paper summarizes a CFD benchmark study comparing industrial state-of-the-art ship-scale CFD predictions of the power reduction through installation of a PSD, where the objective was to both obtain an indication on the reliability in this kind of prediction and to gain insight into how the computational procedure affects the results. It is a blind study, the KVLCC2, which the PSD is mounted on, has never been built and hence there is no ship-scale data available. The 10 participants conducted in total 22 different predictions of the power reduction with respect to a baseline case without PSD. The predicted power reductions are both positive and negative, on average 0.4%, with a standard deviation of 1.6%-units, when not considering two predictions based on model-scale CFD and two outliers associated with large uncertainties in the results. Among the variations present in computational procedure, two were found to significantly influence the predictions. First, a geometrically resolved propeller model applying sliding mesh interfaces is in average predicting a higher power reduction with the PSD compared to simplified propeller models. The second factor with notable influence on the power reduction prediction is the wake field prediction, which, besides numerical configuration, is affected by how hull roughness is considered. © 2022 The Authors

  • 7.
    Awais, Fawad
    et al.
    University of Gothenburg, Sweden.
    Flodén, Jonas
    University of Gothenburg, Sweden.
    Svanberg, Martin
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Logistic characteristics and requirements of Swedish wood biofuel heating plants2021In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 138, article id 110650Article in journal (Refereed)
    Abstract [en]

    The demand for wood biofuel for district heating plants and combined heat and power plants (CHPs) has increased, caused by an increase in both the number and size of CHPs. This places large demands on the logistics system supplying these plants with fuel, with a particular interest in the use of alternative modes of transport such as rail and sea. The aim of this paper is to identify the industry actors’ requirements, constraints, and preferences regarding the wood-biofuel supply chain and to identify the logistical challenges this entails, as well as how this impacts the opportunity for an increased use of alternative transport solutions. A survey was sent to all Swedish CHPs, combined with six interviews with transport companies, terminal operators, and forest companies. The study shows that the industry has a local focus that limits potential logistics and sourcing solutions. It is also challenged by urban sprawl, with expanding residential areas close to the CHPs putting further constraints on the operations. Significant variations in fuel demand, depending on unpredictable outside temperature and seasonal variation, is a further challenge. The low density of the fuel has a negative impact on transport costs and introduces a trade-off between chipping close to the forest to increase density versus more efficient chipping at the CHP. Intermodal transport only used by large plants, driven by a shortage of local fuel. © 2020 The Authors

  • 8.
    Bach, Andreas
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Forsström, Ellinor
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Haraldson, Sandra
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Holmgren, Kristina
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Lind, Kenneth
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Lind, Mikael
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Piehl, Hampus
    RISE Research Institutes of Sweden, Safety and Transport, Electrification and Reliability.
    Raza, Zeeshan
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Rydbergh, Torbjörn
    Marine Benchmark, Sweden.
    HAMNEN SOM ENERGINOD : Ett koncept för hamnens roll i omställningen mot ett hållbart transportsystem2022Report (Other academic)
    Abstract [sv]

    Transportsystemet står inför en enorm utmaning då trycket på genomförandet av hållbara operationer aldrig varit större. Enligt IEA står transportsektorn för 16% av det totala koldioxidutsläppet i världen som med nödvändighet måste minska för att vi ska kunna lämna efter oss en planet med resurser för framtida generationer. Utmaningen kräver att alla delar av transportsystemet gör sitt bidrag, oavsett om det handlar om transportoperatörer, transportnoder, myndigheter på såväl lokal, regional som global nivå och tvärs samtliga transportslag. Det slutar dock inte där, det är lika viktigt att de som konstruerar olika typer av lastbärare och fordon för både gods- och persontransporter också beaktar den energi som förväntas vara tillgänglig i rätt kvantitet och till rätt pris. Energiproducenter behöver också tillgodose att efterfrågade energibärare produceras och finns att tillgå vid rätt plats och i tillräcklig kvantitet då den behövs. Detta är i linje med de behov av insatser som Sveriges regering lyfter inom transporteffektivitet, hållbara förnybara drivmedel samt energieffektiva fordon och fartyg, för att reducera Sveriges territoriella CO2 utsläpp i linje med de globala målen. En viktig del av transportsystemet är hamnar som har fönster mot flera olika transportslag och utgör multimodala noder som förväntas ombesörja en så sömlös övergång mellan olika transportslag som möjligt, såsom till/från sjö, järnväg och väg. Svenska hamnar är inget undantag, utan i Sverige med sin längsta europeiska kustremsa behöver Sveriges hamnar också etablera tillräcklig kapabilitet för att hantera såväl inhemska transportbehov som förväntade transporter för import och export på ett hållbart sätt. Hamnar står inför utmaningen att både bedriva sina operationer på ett så hållbart sätt som möjligt genom nyttjande av fossilfri energi, att förse besökare med fossilfria energibärare, och att balansera sitt nyttjande och distribution av hållbar energi med de behov som omgivningen har. Organisationer med lastbilar, tåg, och fartyg som besöker en transportnod, däribland hamnar, förväntar sig att de kan försörjas med viss energi. Transportnoder kan således inte bara betraktas utifrån att vara en effektiv omlastningspunkt, utan behöver också betraktas utifrån den roll som transportnoden har och kan komma att ta i den del av energisystemet som relaterar till transportsystemet. Hamnar som transportnoder behöver således etablera en förmåga som energinod. I föreliggande projekt har trender beaktats för utvecklingen inom olika transportslag, intervjuer genomförts med svenska hamnar samt en enkätundersökning genomförts riktad till en majoritet av Sveriges hamnar. I projektet identifieras att de viktigaste drivkrafterna för hamnarnas hållbarhets- och omställningsarbete är kundkrav, kostnadsbesparingar, hamnens interna målsättning (ofta baserad på ägarnas krav och vision) samt regelverk. Slutsatsen är att Sveriges hamnar har en stark ambition att utveckla sin förmåga som energinod för olika roller. Samtidigt råder en villrådighet om vilka satsningar som skulle ge störst effekter för hamnens verksamhet. Viktigt att notera är också att olika hamnar har olika förutsättningar och roller i transportsystemet, beroende på dess geografiska placering, storlek och typ av gods / passagerare som hanteras. Samtidigt görs stora investeringar i Sveriges hamnsystem, för att proaktivt utveckla en kapabilitet att möta dagens och morgondagens transportbehov, särskilt i ljuset av den omflyttning som sker från vägbundna transporter till järnväg och sjö. Det är vanligt att hamnar etablerar inlandsterminalskapabilitet, d v s skapar förmåga för omlastning mellan tåg och väg där inte någon sjötransport behöver vara inblandad. Många av Sveriges järnvägsoperatörer ser hamnar som strategiska noder i järnvägssystemet. Dessutom det är tydligt från intervjuerna, vilket även styrks av enkätsvar, att respondenterna anser att otillräckliga finansiella medel, höga kostnader och skatt, omogen teknik, infrastruktur, effekt, standardisering, kompetens, och politisk otydlighet är de största utmaningar som påverkar svenska hamnars roll i hållbarhets- och omställningsarbete. Baserat på genomförd trend- och nulägesanalys föreslås en mognadsmodell som rådgivande för hamnens proaktiva utveckling av sin energinodskapacitet. Denna modell tar utgångspunkt i att hamnen etablerar en energistrategi som tar höjd för nödvändiga samarbeten och investeringar som de både blir tvingade till genom regelverk, påverkade av genom beslut och själva har rådighet över. Hamnarna är tydliga med att huvudverksamheten är att utgöra en transportnod, men att de, för att möjliggöra en omställning mot ett hållbart transportsystem, också behöver ge utrymme för andra aktörer, såsom energiproducenter och energidistributörer att bedriva sin verksamhet relaterat till hamnens geografiska område. Således behöver det kluster av aktörer som ingår i hamnen som nod expanderas till att också innefatta producenter och distributörer av energi. Hamnens energistrategi är rådgivande för att hamnen skall kunna etablera en förmåga som säkerställer att de krav som hamnens operationer, hamnens besökare och hamnens roll med sin geografiska placering, möts. Föreslagen mognadsmodell riktar uppmärksamhet just till dessa nivåer av förmåga och skapar grunder för formuleringen av en proaktiv strategi för den enskilda hamnens roll i transportsystemets energiomställning. En viktig grund blir då att simulera framtida energibehov, såsom inom elförsörjnings- och eldistributionsområdet, men även för andra energibärare, varför detta projekt föreslår ett fortsättningsprojekt där förväntade energibehov kan simuleras och bli rådgivande för strategi, samverkan och investering för Sveriges hamnar. En sådan simuleringsmodell bygger på hamnens digitala förmåga att fånga och använda data från operationer för att säkerställa att hamnen bidrar till transporteffektivitet, användning av hållbara förnybara drivmedel samt energieffektiva fordon och fartyg. Samspelet mellan hamnen som energinod och transportbärares kapabilitet att drivas på hållbar energi samt energiproducenters/energidistributörers förmåga att tillhandahålla fossilfri energi, utgör grunden till fossilfria transporter. Fossilfria väg-, järnvägs- och sjötransporter kan således inte etableras utan att ta hänsyn till alla ingående komponenter. I denna nödvändiga transformation har hamnar och andra transportnoder en nyckelroll.

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  • 9.
    Burden, Håkan
    et al.
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Stenberg, Susanne
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Carlgren, Lisa
    RISE Research Institutes of Sweden, Digital Systems, Prototyping Society.
    Sjöblom, Ted
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Policylabb Smarta Fartyg2022Report (Other academic)
    Abstract [en]

    Swedish Shipping Policy Lab

    Smart ships, or Maritime Autonomous Surface Ships as they are also known, have a great potential to advance shipping and sustainable development through optimisation of operations and maintenance. In situations that pose a risk to humans or where humans tend to lose their concentration, smart ships can also contribute to increased safety onboard and for the environment. In short, smart ships are suitable for operations that are dirty, dull and dangerous. The Swedish Shipping Policy Lab was an initiative to support on-going projects within smart shipping with policy-developing activities with the ambition to strengthen Swedish competitiveness. The project has actively strived for a systematic approach to how shipowners, technology developers and authorities among others can foster policy development and innovation in relation to smart ships. As an outcome the project has identified three policies related to the investigated cases (see Appendix G for more details): 1. Navigational assistance from land – A shared statement by the Swedish Maritime Administration and the Swedish Transport Agency on the role of navigational assistance from land and the need to further investigate the service before it can be regulated in more detail. 2. The Ljusterö Ferry – Certification of ferries is commonly done in relation to an established and consistent set of technical requirements. For smart ships such as the new road ferries procured for the Ljusterö-connection it is reasonable to complement traditional certification with a safety case to ensure that the ship is seaworthy. 3. Smart maritime drones – Ships less than five meters long that do not carry passengers are excluded from national rules regulating the supervision performed by the Swedish Transport Agency. As long as there is no explicit need to inspect a specific ship, the probability of a supervision is low. If an inspection were to incur, it is necessary to show how the smart ship and its operation complies to applicable regulation in terms of laws and collision avoidance. Despite the maritime sector having a long tradition of international governance there are still no international instruments explicitly for smart ships. A conclusion from the policy lab is that while such work is ongoing, there is room for the flag states and their authorities to develop and operate smart ships in accordance with national policies. Or, to paraphrase, smart ships seem suitable for operations that are dirty, dull, dangerous and domestic.

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  • 10.
    Burden, Håkan
    et al.
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Stenberg, Susanne
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Carlgren, Lisa
    RISE Research Institutes of Sweden, Digital Systems, Prototyping Society.
    Sjöblom, Ted
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    The Swedish policy lab for maritime autonomous surface ships2022Conference paper (Refereed)
    Abstract [en]

    The Swedish policy lab for maritime autonomous surface ships, or smart ships, explored three use cases for developing policy in practice. The policies regard smart ships on national waters: one short-term written policy identifying the next shared step for two authorities to position remote navigational assistance as a new service, giving the maritime ecosystem one official position to relate to; one informal policy relying on a mutual trust, where information sharing between an operator of small, unmanned ships and the supervisory authority enables critical competence building; and one evolving policy on the process of certifying autonomous or remote operated functions using non-standardized technology. In conclusion, despite shipping being explicitly regulated internationally we found that there is substantial leeway for national policies regarding smart ships on national waters.

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  • 11.
    Burden, Håkan
    et al.
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Stenberg, Susanne
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Carlgren, Lisa
    RISE Research Institutes of Sweden, Digital Systems, Prototyping Society.
    Sjöblom, Ted
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    The Swedish policy lab for maritime autonomous surface ships2023In: Transportation Research Procedia, ISSN 2352-1457, Vol. 72, p. 1840-1847Article in journal (Refereed)
    Abstract [en]

    The Swedish policy lab for maritime autonomous surface ships, or smart ships, explored three use cases for developing policy in practice. The policies regard smart ships on national waters: one short-term written policy identifying the next shared step for two authorities to position remote navigational assistance as a new service, giving the maritime ecosystem one official position to relate to; one informal policy relying on a mutual trust, where information sharing between an operator of small, unmanned ships and the supervisory authority enables critical competence building; and one evolving policy on the process of certifying autonomous or remote operated functions using non-standardized technology. In conclusion, despite shipping being explicitly regulated internationally we found that there is substantial leeway for national policies regarding smart ships on national waters.

  • 12.
    Carlsson, Annika
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Electrification and Reliability.
    Fast, Lars
    RISE Research Institutes of Sweden, Safety and Transport, Electrification and Reliability.
    Nordin Fürdös, Axel
    RISE Research Institutes of Sweden, Safety and Transport, Electrification and Reliability.
    Adams, Paul
    RISE Research Institutes of Sweden, Safety and Transport, Electrification and Reliability.
    Forsström, Ellinor
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Haberl, Felix
    Volvo, Sweden.
    Johansson, Monica
    Volvo, Sweden.
    Parthav, Desai
    Volvo, Sweden.
    Flytande väte som ett logistiskt bränsle – En förstudie2022Report (Other academic)
    Abstract [en]

    Large investments are being made by energy companies to provide hydrogen production, distribution, and refuelling infrastructure. It is hence critical to find hydrogen pathways that are efficient and feasible. This means deciding between the usage of liquid hydrogen (LH2) or compressed hydrogen (CGH2) value-chains from production to storage onboard vehicles in some transport segments such as heavy-duty trucks. During the project the as yet unestablished concept of cryo-compressed hydrogen (CcH2) was also considered. The project aimed at identifying the critical challenges and current limitations that impact the widespread use of hydrogen as a fuel for transport applications. It has focused on increasing the knowledge about technologies that can make LH2 or CGH2 infrastructure and vehicle usage more efficient and safer, by assessing the current state of technology as well as maturity and potential of new technologies. Included in this was also a segment focused on the safety of the different alternatives along the later parts of the value-chain. The project as a whole was conducted as a literature study. For the technology maturity in different parts of the value-chain the project has summarized the results in a very high-level categorisation system, see table below The definitions are mainly qualitatively and show where the technologies are in these categories: • Established (Used on a larger scale, ~TRL 9-10) • Proven concept (Demonstrators or soon reaching this stage, ~TRL 7-8) • Initial design (No public demonstrators available, ~TRL 3-6) • Uncertain applicability (Applicability was not established in this work) • Not applicable (Cannot be used for this state of hydrogen) Technological maturity in the hydrogen value-chain The table above also gives an overview of the segments included in the report. In combination with the technological evaluation a qualitative cost analysis of the different hydrogen storage states was also done. Here it is indicated that though LH2 has a higher cost in the initial part of the value-chain, it has lower costs in the end segments. Therefore, it is possible that the end-price for the user will be similar for both LH2 and CGH2. The full cost can be compared first when LH2 refuelling stations and vehicles are publicly built, and cost information is available. The same is true for CcH2. During the safety, regulations and standards pre-study the following was concluded. From a safety perspective, there are no insurmountable barriers with respect to the use of LH2 on-board heavy-duty road vehicles in the medium term, however, there are several challenges to overcome, not least in the short term. Within the EU there are regulations which allow the type-approval of heavy-duty road vehicles with LH2 storage systems. However, these are based on work undertaken 15 - 20 years ago and are widely acknowledged as in need of being updated and validated in the same way that CGH2 road vehicle regulations have been. Similarly, there is a lack of up-to-date industry standards for road vehicle LH2 storage systems. A particular gap is the absence of an up-to-date standard that can be referenced in regulations for the refuelling receptacle geometry. Additionally, for LH2 refilling stations as a whole there are no suitable, up to date international standards, so there is a risk that individual countries set their own requirements. Overall, the project concluded that there are no show-stoppers for the implementation of LH2. It is a feasible value-chain from both the technology, cost and safety perspective. It could also in the future become comparable with the more proven CGH2 value-chain, but some initial hurdles and investments need to be overcome.

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  • 13.
    Castrellon, Juan Pablo
    et al.
    Chalmers University of Technology, Sweden; Universidad Nacional de Colombia, Colombia.
    Sanchez-Diaz, Ivan
    Chalmers University of Technology, Sweden.
    Roso, Violeta
    Chalmers University of Technology, Sweden.
    Altuntas-Vural, Ceren
    Chalmers University of Technology, Sweden.
    Rogerson, Sara
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Santén, Vendela
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Kalahasthi, L. K.
    Chalmers University of Technology, Sweden.
    Assessing the eco-efficiency benefits of empty container repositioning strategies via dry ports2023In: Transportation Research Part D: Transport and Environment, ISSN 1361-9209, E-ISSN 1879-2340, Vol. 120, article id 103778Article in journal (Refereed)
    Abstract [en]

    Trade imbalances and global disturbances generate mismatches in the supply and demand of empty containers (ECs) that elevate the need for empty container repositioning (ECR). This research investigated dry ports as a potential means to minimize EC movements, and thus reduce costs and emissions. We assessed the environmental and economic effects of two ECR strategies via dry ports—street turns and extended free temporary storage—considering different scenarios of collaboration between shipping lines with different levels of container substitution. A multi-paradigm simulation combined agent-based and discrete-event modelling to represent flows and estimate kilometers travelled, CO2 emissions, and costs resulting from combinations of ECR strategies and scenarios. Full ownership container substitution combined with extended free temporary storage at the dry port (FTDP) most improved ECR metrics, despite implementation challenges. Our results may be instrumental in increasing shipping lines’ collaboration while reducing environmental impacts in up to 32 % of the inland ECR emissions. © 2023 The Author(s)

  • 14.
    Coslovich, Franciesco
    et al.
    Chalmers University of Technology, Sweden.
    Kjellberg, Martin
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Östberg, Magnus
    Flowtech International AB, Sweden.
    Janson, Carl-Erik
    Chalmers University of Technology, Sweden.
    Added resistance, heave and pitch for the KVLCC2 tanker using a fully nonlinear unsteady potential flow boundary element method2021In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 229, article id 108935Article in journal (Refereed)
    Abstract [en]

    In this paper, a fully nonlinear unsteady potential flow method is used to predict added resistance, heave and pitch for the KVLCC2 hull in regular head waves at design speed. The method presents a nonlinear decomposition of the velocity potential and the wave field and an adaptive grid refinement. A formulation for the acceleration potential is used to obtain the pressure. To improve computational efficiency, a Barnes-Hut algorithm is introduced. A grid dependency study and a study on the impact of different time steps on the solution are performed. Numerical results have been compared with experimental data for the design speed. A general good agreement is found for added resistance, especially for longer waves. Heave and pitch are properly computed for all wave lengths in the range λ/Lpp=0.4 to 1.4. © 2021 The Author(s)

  • 15.
    Costa, Nicole
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Final and Complete Report of SSPA’s Tasks in FAMOS Odin2018Report (Other academic)
    Abstract [en]

    This document reports the methods used and results obtained for the tasks established between SSPA and the FAMOS Odin project, as follows:Baseline analysis of traffic in the Baltic Sea, using collected AlS dataa.Analysis of safe Under-Keel Clearance (UKC) used in today’s trafficb.Analysis to which extent transport capacity is currently limited by UKCc.Calculation of the added fuel consumption caused by the squat effectSimulation of traffic based on improved bathymetry and UKC controla.Present energy efficient routing options with regards to distance, UKC and squatb.Calculate the benefits of optimized UKC for increased cargo capacityc.Use and test S-102 data as a basis for these analyses.This document reports as well the active partner’s budget outcomes, milestones and gains accomplished within the project timeframe.Analyses based on bathymetric and Automatic Identification System (AIS) data evidenced, for a chosen area of interest in the Baltic Sea, that tankers may be limited by UKC and as a result carry less cargo, which could amount to 1% more of the total cargo transported through the Baltic Sea, according to the model used. The results also show the linear relationship between the increase of speed and squat effect with the subsequent increase of water resistance and need of energy to propel the ship, signifying a direct increase in fuel consumption. Finally, the results emphasize certain regions of the Baltic Sea where routes could especially benefit from optimization for reduced fuel consumption, yet optimization results may depend on different route parameters prioritized by the mariner (e.g, speed vs. Estimated Time of Arrival (ETA)).Some recommendations for futures stages of this project include access to higher-fidelity depth data for Swedish waters to refine the studies described in this report, as well as the inclusion of a qualitative research component to investigate how UKC is perceived by the mariners or what reasons they may have for keeping a certain UKC or loading cargo to a certain weight.

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  • 16.
    Costa, Nicole
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Weber, Reto
    Chalmers University of Technology, Sweden.
    Olsson, Fredrik
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Algell, Johan
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Testing Proof of Concept of a Web-Based Ship Manoeuvring Training Tool in the Classroom2019Conference paper (Other academic)
    Abstract [en]

    Currently, real-time ship manoeuvring simulations are confined to static environments e.g., desktop/full-mission bridge simulators. Seaman Online™ is a novel web-based ship manoeuvring training tool allowing students and professional mariners to practice manoeuvres in ports and confined waters from their personal computers. This paper describes the tool’s first-time implementation in a Master Mariner university programme. The students were asked to complete a post-questionnaire regarding their use experience and the results were discussed between the course instructors and the toolproviding organization at two debriefings. The aim was to obtain feedback about (a) the usefulness of the tool in manoeuvring training; (b) further design improvements and usability; and (c) how to best incorporate it into the programme curriculum in coming academic years for improved user experience. Results revealed usability and maturity issues and the need for further guidance on simulation-based training objectives and limitations. Overall, the tool’s usefulness and potential in individual manoeuvring training were demonstrated.

  • 17.
    Costa, Nicole
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Williamsson, Jon
    Ekholm, Johan
    Santén, Vendela
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Rogerson, Sara
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Borgh, Martin
    Connecting vessels to shoreside electricity in Sweden2022Report (Other academic)
    Abstract [en]

    The purpose of the KAJ-EL project was to offer decision support to ports and shipping companies about the implementation and use of shoreside electricity in Swedish ports. More specifically, this project investigated the following, among other questions related to shore power: • the driving forces and barriers among ports and shipping companies to offer or use shore power; • the decision making, steps and actors involved in the process of adopting shore power; • the costs and business arrangements for installing and operating shore power; • the challenges in the installation and operation of shore power; • the different shore power equipment used in Swedish ports and on board vessels; • the actions and condition to realise OPS adoption to a larger extent. The project group included researchers and experts in shipping, transport, logistics, economics, and human factors from SSPA and the University of Gothenburg, and included industry partners Svensk Sjöfart (Swedish Ship Owners’ Association) and Sveriges Hamnar (Ports of Sweden). In addition, industry and authorities were involved in a reference group with representatives from shipping companies, ports and electricity providers. Interviews were performed with various ports in Sweden, a port in Norway (Kristiansand) as well as the US ports of Long Beach and Seattle to compare the perspectives. Shipping companies were interviewed, as were a number of OPS equipment manufacturers, national grid operators and electricity providers. Two workshops and a final seminar were also conducted. This report presents an overview of the OPS situation in Sweden and provides principles for business models as well as recommendations for ports’ and shipping companies’ OPS work. It can be noted that Sweden is at the European forefront of OPS in the sense that it currently has nine cities offering OPS, with main focus so far on the ro-pax and ferry segment. Actors, in particular ports, perceive that the regulatory pressure to offer OPS is increasing and the knowledge about OPS, especially among non-experienced ports, is still limited. Further guidance on OPS installations and operations is therefore needed, in terms of the financial, business, technical and operational issues that the actors must deal with. One major question is how to secure the electricity supply to the ports. Collaboration between actors is key to successful OPS implementation and a higher level of standardisation can facilitate technical choices. Several areas in need of further research are highlighted in this report, such as investigating possible future power demand scenarios from using OPS, and supply strategies for ports. The project received funding from Trafikverket (The Swedish Transport Administration).

  • 18.
    Dahlbom, Sixten
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Sanfridson, Martin
    RISE Research Institutes of Sweden, Safety and Transport, Measurement Technology.
    Sjöblom, Ted
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Evaluation of Detection Principles and Challenges in Early Detection of Thermal Runaway in Batteries2023Report (Other academic)
    Abstract [en]

    The amount of battery electrical vehicles (BEVs) carried as cargo on ro-ro ships is increasing. The possibility of thermal runaway in a lithium-ion battery makes BEVs a different fire risk compared to internal combustion engine vehicles (ICEV). One of the challenges that arise is how to detect a thermal runaway early. Current detection systems in ro-ro spaces generally consist of smoke and/or heat detection. To identify potential techniques and challenges for detection of a thermal runaway, as early as possible, tests with batteries and detectors are needed. Tests with one battery cell were performed inside an ISO container (with almost negligible ventilation) as well as in an open room with moderate ventilation (14 air changes per hour). Point-type detectors (two smoke and heat detectors, one CO detector, and one LEL detector), thermal imaging, video analytics, and light detection and ranging (LIDAR) were evaluated in the tests. A total of 14 tests were conducted. The detectors were evaluated in different positions relative to the battery cell and comparative tests with wood-sticks were performed to investigate the detectors’ ability to detect a more conventional source of fire. Based on the results, it can be concluded that early detection of thermal runaway in batteries is possible in principle. However, detection is a matter of circumstances e.g., ventilation, gas/smoke production and the location of the detector(s). The result indicates that detection in a small and confined space is relatively manageable, but detection in a large and open space could be more of a challenge. If the gas/smoke is cooled down it may sink and spread along the floor/deck, instead of rising and spreading along the ceiling. This would be a challenge with current smoke detectors installed in the ceiling. Shielding may be a problem, especially with LIDAR and thermal imaging. Future research should address full-scale tests, and it is recommended to include Optical Gas Imaging (OGI) as a mean of detection.

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  • 19.
    Daniel, Vergara
    et al.
    Chalmers University of Technology, Sweden.
    Alexandersson, Martin
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department. Chalmers University of Technology, Sweden.
    Xiao, Lang
    Chalmers University of Technology, Sweden.
    Wengang, Mao
    Chalmers University of Technology, Sweden.
    A machine learning based Bayesian decision support system for efficient navigation of double-ended ferries2023In: Journal of Ocean Engineering and Science, ISSN 2468-0133Article in journal (Refereed)
    Abstract [en]

    Ships can be operated more efficiently by utilizing intelligent decision support integrated with onboard data collection systems. In this study, a Bayesian optimization-based decision support system, which utilizes ship performance models built by machine learning methods, is proposed to help determine the operational set-points of two engines for double-ended ferries. By optimizing the ferries’ power allocation between the stern and bow engines, the Decision Support System (DSS) will simultaneously attempt to keep the ETA of the ferry fixed under a set of operational constraints using the Bayesian optimization. Its objective is to minimize fuel consumption along individual trips. Based on simulation environment, the DSS can reduce at maximum 40 % fuel consumption with no significant change of the ETA. Final full-scale experiments of a double-ended ferry demonstrated an average of 15 %, where at least half of this saving was achieved by the optimized power allocation between bow and stern engines. 

  • 20.
    de Alwis, Pahansen
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Riding the waves: Kidney belt-mounted accelerometers to measure lumbar spine vibrations in high-speed craft occupants2023Report (Other academic)
    Abstract [en]

    The scientific investigation into the viability of employing kidney-belt-mounted accelerometers to quantify shock and vibration exposure in the lumbar spine region of occupants in high-speed marine craft, and their concordance with prevailing standards, has been heretofore unexplored. Addressing this research gap, a series of meticulously designed laboratory and field experiments were undertaken. In the laboratory setting, two test subjects were engaged in predefined body movements, with accelerations recorded using both body-mounted and kidney-beltmounted accelerometers. This controlled environment allowed for a comparative analysis of the efficacy of the two accelerometer configurations in capturing lumbar spine accelerations. Field experiments expanded upon these findings, involving the recording of acceleration exposures during a high-speed marine craft exercise. The kidney-beltmounted accelerometers were utilized alongside seat-mounted accelerometers to assess their applicability in real-world dynamic conditions. The results revealed that kidney-belt-mounted accelerometers effectively captured lumbar spine accelerations during basic body movements, particularly when the torso was maintained in an upright position. However, the translation of these measurements into a framework aligned with existing international standards encountered substantial challenges during the field experiment. This study underscores the potential utility of kidney-belt-mounted accelerometers for lumbar spine acceleration measurement in controlled environments. Nevertheless, the complexities associated with aligning these measurements with established international standards were evident, highlighting the need for further consideration and refinement. The implications of this research extend to the recognition that current standards may not fully address the intricacies of shock and vibration exposure in the lumbar spine region within the dynamic context of high-speed marine craft environments. Consequently, there is a clear call for the development of standards specifically tailored to these operational conditions to ensure a comprehensive and accurate assessment of lumbar spine health in marine craft occupants.

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  • 21.
    de Alwis, Pahansen
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Garme, Karl
    KTH Royal Institute of Technology, Sweden.
    Feasibility of Using Kidney-Belt-Mounted Accelerometers for Measuring Shock and Vibration Exerted on the Lumbar Spine Region of High-Speed Marine Craft Occupants2023In: Progress in Marine Science and Technology, IOS Press BV , 2023, Vol. 7, p. 233-240Conference paper (Refereed)
    Abstract [en]

    The feasibility of using kidney-belt-mounted accelerometers for measuring the shock and vibration exposure in the lumbar spine region of high-speed marine craft occupants and evaluating them on a par with the current standards remain largely unexplored in scientific literature. To address this gap a series of laboratory and field experiments were conducted. In the laboratory experiments, two test subjects performed predefined body movements while accelerations were measured using body-mounted and kidney-belt-mounted accelerometers. Field experiments involved recording acceleration exposures of two test subjects using the kidney belt arrangement and seat-mounted accelerometers during a high-speed marine craft exercise. Results suggest that kidney-belt-mounted accelerometers effectively measure lumbar spine accelerations during basic body movements with an upright torso. However, evaluating vibration exposures measured with the kidney belt arrangement using existing international standards proved challenging in the field experiment. 

  • 22.
    Dixit, Saubhagya
    et al.
    Scientist Central Pollution Control Board, India.
    Rao, K Ramachandra
    Indian Institute of Technology, India.
    Tiwari, Geetam
    Indian Institute of Technology, India.
    von Wieding, Sönke
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Urban freight characteristics and externalities – A comparative study of Gothenburg (Sweden) and Delhi (India)2022In: Journal of Transport and Supply Chain Management, ISSN 2310-8789, E-ISSN 1995-5235, Vol. 16, article id a629Article in journal (Refereed)
    Abstract [en]

    Background: The urban freight transportation (UFT) system is an essential facilitator for the smooth functioning of city logistics. It also contributes significantly to transportation-related issues, such as vehicular congestion, pollution, accidents, infrastructure damage and other related problems. Objectives: This study aimed to understand and compare the urban freight traffic characteristics and their impact in two cities: Gothenburg, Sweden and Delhi, India, having high socio-economic differences. The findings of this study will be helpful for practitioners and policymakers in the development and successful implementation of UFT management policies. Method: Using the cordon count (traffic data), retailers’ interviews (receivers’ data) and freight vehicle drivers’ interviews, UFT characteristics such as sector-specific contribution, trip characteristics, vehicular characteristics and negative impacts in terms of external cost to society are evaluated. This study also discusses the prediction of attracted trips in the study zone using freight trip attraction (models. Results: About 75% of the trips in Gothenburg and 92% of the trips in Delhi are made by light commercial and other small-sized vehicles. Gothenburg has formally organised sectors involved in freight vehicle movement; however, Delhi has informally organised sectors. Conclusion: The results revealed substantial differences in characteristics of freight trip operations in both the cities, compared with few similarities. Measures taken considering the specific local attributes of freight traffic and stakeholders’ requirement may lead to a sustainable transportation system in cities. © 2022. The Authors.

  • 23.
    Eriksson, Anna
    et al.
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Cederstav, Fredrik
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Ranäng, Sara
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Lyrberg, Magnus
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Einarsson Lindvall, Elin
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    von Wieding, Sönke
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Slutrapport inom Gothenburg Green City Zone (GGCZ): Metodik för analys och införande av klimatneutrala mobilitets- och transportlösningar i städer2024Report (Other academic)
    Abstract [sv]

    Denna rapport är ett arbetsdokument som har efterfrågats i arbetet inom Gothenburg Green City Zone (GGCZ), där det pågår en process för att ta fram en mer detaljerad planering för en övergång till helt fossilfria transporter i Göteborg. Rapporten resonerar först kring zonbegreppet, vilken forskning som tidigare gjorts, vilka slags zoner som redan finns och som implementerats i Sverige och Europa. Rapporten föreslår sedan en metodik för hur zoner kan definieras och hur en generell zonindelning skulle kunna upprättas som skulle kunna användas som mall för både Göteborg och andra städer. Arbetet är inte färdigt utan kommer att fortsätta under kommande år både inom RISE och tillsammans med övriga samarbetspartners. Det som kvarstår är att definiera i detalj vilka parametrar och egenskaper som gör en viss zon unik, exempelvis genom mätetal som stadsdelars täthet, demografi, socioekonomiska förhållanden, infrastruktur samt befintlig framkomlighet. Målet med arbetet har varit att utveckla och förbättra kunskapen om zonmetodiken, visa på dess möjliga fördelar och utveckla ett verktyg för att användas i omställningen och att hjälpa Göteborg och andra städer att lyckas med omställningen mot klimatneutrala transporter till år 2030.

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  • 24.
    Eriksson, Anna
    et al.
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    von Wieding, Sönke
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Gestrelius, Sara
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Lyrberg, Magnus
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Ranäng, Sara
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Carlén, Vanja
    Closer, Sweden.
    Hansson, Marcus
    Closer, Sweden.
    REDIG- Regionala godshubbar i Göteborg: FÖRSTUDIE – DRIVE SWEDEN2023Report (Other academic)
    Abstract [sv]

    Denna rapport är ett resultat av en förstudie kring en logistik- och transportlösning (som kan realiseras i form av en gemensam hubb) för aktörer som är placerade i evenemangsstråket i Göteborg. Rapporten svarar på frågor kring nulägesanalys av aktörernas logistiklösningar, leveranstrafik inom evenemangsstråket, samt hur leveranstrafik kan se ut under 2030+ om inga förändringar i leverans/logistikupplägget görs. En viktig slutsats som framgår är att det krävs åtgärder som minskar leveranstrafiken, eftersom elektrifiering av fordon inte kan eliminera trängsel och buller som står för den största delen av de samhällsekonomiska kostnaderna. Utan förändringar i logistikupplägget och fordonsflottan förväntas de samhällsekonomiska kostnaderna öka med cirka 30%. Förändringar i logistikupplägget kan nås genom ett optimerad trafikflöde, vilket i sin tur kan realiseras genom en gemensam samlastningshubb för små och fragmenterade flöden som kan minska antalet anlöp och fordonstrafiken i området. Baserat på intervjuer med aktörerna, studiebesök, studerande av underlag, workshops och analys av logistikbehoven, kan det sammanfattas att verksamheterna, utmaningar och logistikbehoven i stort sett är ganska lika. En gemensam extern hubb kan frigöra yta hos verksamheterna som kan användas för att skapa nya affärsmöjligheter. En möjlighet för att upphandla en tredjeparts logistik- och transportlösning är att bygga ett konsortium där alla aktörer delar på kostnaden för terminalhantering samt samlastning/samkörning. Det finns stora möjligheter att hitta lösningar för logistikhubb som uppfyller kraven på geografisk närhet och säkra leveranser i trafiksystemet – och det är klokt att anpassa leveranstider för att undvika trängsel. Det finns en vilja hos aktörerna att minska transporterna, anpassa sin verksamhet för effektivisering vid mottagning och förvaring, ställa om mot fossilfrihet och på det sättet bidra till transporteffektivitet som krävs för att nå mål inom klimatneutralitet 2030. Det finns stora behov för förändring i trafikflödet inom GGCZ och det finns en stor potential att optimera det genom att konsolidera och styra leveranser.

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  • 25.
    Eslamdoost, Arash
    et al.
    Chalmers University of Technology, Sweden.
    Larsson, Lars
    Chalmers University of Technology, Sweden.
    Brown, Matz
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    A device for reducing the resistance of transom stern hulls2021In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 235, article id 109351Article in journal (Refereed)
    Abstract [en]

    A novel idea to reduce the resistance of a transom stern hull in displacement and semi-planing modes is investigated. By placing a spoon-shaped device in the recirculating zone behind the transom, the momentum of the forward-moving water will be absorbed, and a pushing force generated on the device. Numerical and experimental techniques are applied on a transom stern hull to optimize the shape and position of the device and to explore in detail the physics behind the gain. For the towed hull at a Froude number of 0.4, the maximum measured resistance reduction is 11%, while the computed maximum reduction is 17%. In self-propulsion with one propeller, the measured power reduction is 15%. The power cannot be computed with the applied propeller model, which is an axial body-force distribution in the propeller disk, but the reduction in thrust using the device is 11%. More significant gains are possible at smaller Froude numbers, while the effect is reduced at higher Froude numbers. Larger gains are achieved by splitting the thrust on two propellers. © 2021 The Authors

  • 26.
    Finnsgård, Christian
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Liefvendahl, Mattias
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Ship power prediction with CFD in full scale2023Report (Other academic)
    Abstract [en]

    This report demonstrates the qualifications of RISE to carry out CFD for ship self-propulsion, thus predicting the delivered power. The procedures were fully developed at SSPA which became fully integrated into the Maritime Department of RISE by 2023-01-01. An outline is given of the best-practice guidelines used at SSPA/RISE and how they comply with the relevant ITTC recommendations for verification and analysis. In addition, an overview is given of previous validation studies performed for a wide range of ships, including comparison with both model-scale and full-scale data. Complete references are provided to reports and publications in which these SSPA studies and methods are described in detail.

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  • 27.
    Forsman, F.
    et al.
    Chalmers University of Technology, Sweden.
    Finnsgård, Christian
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department. Chalmers University of Technology, Sweden.
    Teamwork as joint activity in sailing2016Conference paper (Refereed)
    Abstract [en]

    Sailing is a sport and activity that takes a long time both to learn and to master, as much of its competence-based knowledge is acquired through experience. Experiencebased learning is very important, time-intensive, and the factors for success are often tacit and hidden. Should these success factors become explicit and salient, learning would occur faster and produce obvious competitive advantages. This research was conducted by embedding on-going research results into two competitive sailing teams racing in different classes, one offshore keelboat racing with a crew of eight, and a one-design Star-class racing yacht with a crew of two. The data collection consisted of observations, interviews, and video recordings. The results were also verified with the crews to catch biases in the analysis process. A jibe, a specific but common maneuver was analyzed from the perspective of Common Ground within Joint Activity. Maneuvering a competitive offshore sail racer or a previously Olympic Star-class yacht are tasks that fulfill the requirements for Joint Activity. A high level of Common Ground is required for the effective coordination needed in order to perform at a high level and maintain the safety of the crew and equipment. Breakdowns in the coordination of maneuvers were observed, although they must be recorded on video for higher analysis reliability. To achieve greater validity, more and different maneuvers should be considered within the analysis. By better understanding the factors for success, sail racing teams can more quickly gain competence and thus competitive advantages. The research analyzes the teamwork found in sailing from the perspective of Joint Activity and Common Ground and provides insight into how to achieve performance improvements more efficiently. 

  • 28.
    Gerhardt, Frederik
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Case study: IMO minimum propulsion power to maintain the manoeuvrability of KVLCC2 tanker in adverse conditions2024Report (Other academic)
    Abstract [en]

    The introduction of the EEDI more than a decade ago, slow steaming, and the wish to reduce bunkering costs have resulted in a trend to install less powerful engines in ships. To avoid vessels becoming underpowered and thus unsafe, the International Maritime Organization (IMO) has published a guideline regarding the “Minimum Propulsion Power to Maintain the Manoeuvrability of Ships in Adverse Conditions”. This report presents a case study that follows the IMO-guideline step by step and works out the minimum engine size for the KVLCC2 tanker. Using a combination of Computational Fluid Dynamics and model tests, the parameters and assumptions behind the guideline are discussed in some detail. Results show that it is particularly important to determine the added resistance in waves correctly because it dominates the power prediction. It becomes clear, that the selection of the propulsive factors, particularly the “thrust deduction factor” has a significant influence on results. The work summarised here is part of a wider project that aims to provide experimental benchmarking data for added resistance predictions. It has been sponsored by the Swedish Transport Administration (Trafikverket) under grant number TRV 2021/53938.

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  • 29.
    Gerhardt, Frederik
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Werner, Sofia
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Hörteborn, Axel
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Lundbäck, Olov
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Nisbet, J
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Olsson, Tobias
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    HORSES FOR COURSES: HOW TO SELECT THE “RIGHT” WIND PROPULSION SYSTEM AND HOW TO MAKE THE BUSINESS CASE2021Conference paper (Other academic)
    Abstract [en]

    Wind propulsion systems (WPS) are major investments and the decision to install them requires careful consideration of many complex questions. In this paper we present a systematic, scientific methodology to assess the benefits and drawbacks of such systems at the early concept stage of a vessel. The purpose is to provide guidance for shipowners and operators and help them make informed decisions. The proposed method was developed into a Software tool called ‘SEAMAN Winds’ and has been correlated to full scale results. The program draws on our large database of model tests, and CFD of hulls and wind propulsion technologies. It uses the intended trading routes of the vessel as an important input, typical output data are: a) performance values (ship speed, power requirements etc.) b) environmental parameters (CO2 avoided, EEDI and EEXI reduction, carbon intensity indicator) c) financial metrics (bunker savings, payback time for installation of WPS) Potential applications of the method include making the business case for one particular WPS or investigating in how far certain systems are more suited for a specific route than others.

  • 30.
    Gerhardt, Frederik
    et al.
    SSPA Sweden AB, Sweden.
    Werner, Sofia
    SSPA Sweden AB, Sweden.
    Li, Da-Qing
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department. SSPA Sweden AB, Sweden.
    Malmek, Karolina
    SSPA Sweden AB, Sweden.
    Levelling the Playing Field: A Numerical Platform for the Fair Comparison of Wind Propulsion Systems2022Conference paper (Other academic)
    Abstract [en]

    Wind propulsion systems (WPS) are major investments and the decision to install them requires careful consideration of many complex questions. One of the recurring and challenging issues for ship owners is the choice of a suitable WPS for a specific ship and a specific operational pattern. Today most WPS providers offer on-demand case studies, but obviously the underlying performance prediction methodologies differ from provider to provider. This makes comparing different technologies from competing suppliers next to impossible. In this paper we present a numerical platform to compare different WPS of different makes, sizes, and costs in a fair way. The fundamental idea is to use aerodynamic WPS datasets that are independently verified by SSPA through wind tunnel test, sea trials or extensive CFD. This is combined with a hydrodynamic dataset from SSPAs database of tank tests. The same performance prediction method, identical routes and weather statistics are then used to determine Key Performance Indicators and financial metrics of the competing wind propulsion technologies. The purpose is to provide guidance for shipowners at the early concept stage of a vessel and help them select a system that suits their particular requirements.

  • 31.
    Gypa, Ioli
    et al.
    Chalmers Tekniska Högskola, Sweden.
    Jansson, Marcus
    Kongsberg Maritime Sweden AB, Sweden.
    Gustafsson, Robert
    Kongsberg Maritime Sweden AB, Sweden.
    Werner, Sofia
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Bensow, Rickard
    Chalmers Tekniska Högskola, Sweden.
    Controllable-pitch propeller design process for a wind-powered car-carrier optimising for total energy consumption2023In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 269, article id 113426Article in journal (Refereed)
    Abstract [en]

    Wind-powered ship propulsion (WPSP) is the concept where the wind is the main source of thrust, while the traditional propulsion system operates when needed. This type of propulsion can lead to considerably reduced emissions, something that the shipping community is striving for. A well-known example of WPSP is the Oceanbird with the goal to cut emissions of up to 90%. In this study, the propeller design process for a wind-powered car-carrier (wPCC) such as the Oceanbird is investigated, what the various challenges of WPSP are and therefore how an automated optimisation procedure should be approached. A controllable-pitch propeller was selected as suitable propeller type for the operation of the wPCC, and various functions such as windmilling, feathering and harvesting have been explored. Regarding the optimisation procedure, an essential input is the definition of the operational profile, in order to determine the most important conditions for the route. The main objective of the optimisation is the minimisation of the total energy consumption (TEC), calculated based on a selection of conditions using the potential flow solver MPUF-3A. Cavitation has been evaluated by the blade designer, through an interactive optimisation method. The results showed that designing and optimising for the most highly loaded condition led to solutions with the lowest TEC. © 2022 The Author(s)

  • 32.
    Gypa, Ioli
    et al.
    Chalmers University of Technology, Sweden.
    Jansson, Marcus
    Kongsberg Maritime Sweden AB, Sweden.
    Gustafsson, Robert
    Kongsberg Maritime Sweden AB, Sweden.
    Werner, Sofia
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Bensow, Rickard
    Chalmers University of Technology, Sweden.
    Propeller design procedure for a wind-assisted KVLCC22022In: PRADS 2022 Book of Abstracts, 2022Conference paper (Refereed)
    Abstract [en]

    Wind-assisted ship propulsion (WASP) has received much attention lately with research focusing on the different sail technologies, ship-hull design optimisation and weather route optimisation. However, the traditional propulsion system is still needed for wind assisted vessels and is associated with several challenges, related to the wide range of operating conditions and propeller loads due to the varying degree of wind-assistance that will occur. In this study we use an interactive design and optimisation methodology applied on propellers of wind-assisted vessels. The methodology involves handling the complete operating profile of the propeller, an optimisation method for interactive cavi-tation evaluation by the blade designer, and the use of a new objective, the total energy consumption (TEC) of the expected operation. We use a case study where the KVLCC2 tanker is retrofitted with six Flettner rotor sails, operating between two fixed destinations at constant speed. The purpose is to investigate to what extent a new propeller design can offer a significantly lower TEC when compared to the existing design. Based on the results of this study, approximately 0.9% further reduction in TEC was achieved with the WASP adapted propeller compared to the existing one.

  • 33.
    Huang, Chen
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Temple, Alastair
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Ramachandra, Vasudev
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Anderson, Johan
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Andersson, Petra
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Modelling thermal runaway initiation and propagation for batteries in dwellings to evaluate tenability conditions2022Report (Other academic)
    Abstract [en]

    Thermal propagation is one of the major challenges when batteries will be used in dwellings in large scale. It means the exothermic reactions in the cell are out of control and can lead to a fast release of flammable and toxic gases. In a system involving a large number of cells, thermal runaway can rapidly propagate from one battery cell to the whole system, which means substantial fire and explosion risks, an event that is important to mitigate and prevent. Multi-physics simulations together with full-scale testing is a cost-effective method for designing safer batteries. This project aims at simulating thermal runaway initiation and propagation using a multi-physics commercial software GT-Suite. 

    A battery thermal runaway model containing 12 prismatic cells based on 3-D Finite Element approach was built using GT-Suite. The computed thermal runaway time instants versus thermal runaway cell number were compared with full-scale experimental data with reasonable agreement. Quantitative sensitivity study on the model input parameters and model space and time resolutions on the computed start time instant and time duration of thermal runaway were performed. The thermal runaway model was then extended with an electric equivalent sub-model to simulate the short circuit. With the electrical model acting as the input to the thermal model, the most interesting output of the simulation is the change in temperature of the cells, dependent on the current in the cells, with respect to time. The current is determined by the value of the external resistance through which the short takes place and the voltage level of the battery pack. The obtained results from the above short circuit simulations can only be used as a starting point and not as absolute values for neither triggering the thermal model nor for accurately simulating a battery under an electrical load. Furthermore, GT-Suite was applied to simulate the gas dispersion inside a room. A comparative study of the dispersion of toxic gases during thermal runaway, utilising an arbitrary release of HCN to represent the battery gases, in a small compartment with natural ventilation was investigated and the results compared the same situation simulated in FDS. The pipe based modelling supported by GT-Suite has limited applicability and overestimated the concentrations close to the ceiling whereas the lateral concentrations where underestimated. 

    The multi-physics model for battery thermal runaway process is promising and worth to be applied with care for designing safer batteries in combination with full-scale testing. 

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  • 34.
    Hörteborn, Axel
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department. Chalmers University of Technology, Sweden.
    Allision modelling in IWRAP Mk II – A verification and sensitivity study: Chapter 82023In: Advances in the Collision and Grounding of Ships and Offshore Structures: PROCEEDINGS OF THE 9th INTERNATIONAL CONFERENCE ON COLLISION AND GROUNDING OF SHIPS AND OFFSHORE STRUCTURES (ICCGS 2023), NANTES, FRANCE, 11-13 SEPTEMBER 2023, CRC Press, 2023, Vol. 12, p. 51-58Chapter in book (Refereed)
    Abstract [en]

    Risk assessment is important both while planning to build new infrastructure and for maintenance of existing structures. The probability of ship-structure allisions could be estimated with IWRAP Mk II, which is a commonly used software for estimating maritime risks. However, the research coverage of the software is limited with regards to groundings and allisions. The aim of this study is to verify how IWRAP Mk II estimates the accident probability. To perform this verification a separate tool is constructed, OMRAT, based on the same theory as IWRAP Mk II. The aim is also to highlight the sensitivity of different parameters in these types of models. It is concluded that IWRAP Mk II estimates the probability of allisions and groundings with the same equations. Another conclusion is that some parameters have a linear effect on the accident probabilities and other parameters are also influenced by the model layout.

  • 35.
    Hörteborn, Axel
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department. Chalmers University of Technology, Sweden.
    Hassellöv, Ida-Maja
    Chalmers University of Technology, Sweden.
    Economic incentives and technological limitations govern environmental impact of LNG feeder vessels2023In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 429, article id 139461Article in journal (Refereed)
    Abstract [en]

    In the transition to sustainable shipping, Liquified Natural Gas (LNG), is proposed to play a role, reducing emissions of sulphur and nitrogen oxides, and particulate matter. However, LNG is a fossil fuel and there is an ongoing discussion regarding the extent of methane slip from ships operating on LNG, challenging the assumptions of LNG as a sustainable solution. Here we show another aspect to consider in the environmental assessment of shipping; LNG feeder vessels may spend as much as 25% of their time at sea just running the ship to ensure the pressure in the tanks are not exceeded, i.e., run time not directly attributed to the shipment of gas from one port or ship, to another. In other words, the economic incentives are currently allowing for roughly 32% increase of the ships’ operational emissions and discharges and increased navigational risks. Most coastal areas are heavily affected by anthropogenic activities and e.g., in the Baltic Sea there is consensus among the HELCOM member states that the input of nutrient and hazardous substances must be reduced. Even if the LNG feeder vessels are currently few, the possibility to reduce their environmental impact by 32% should be an attractive opportunity for future policy measures and investigation of technological solutions of the problem. 

  • 36.
    Hörteborn, Axel
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department. Chalmers University of Technology, Sweden.
    Ringsberg, Jonas W
    Chalmers University of Technology, Sweden.
    A method for risk analysis of ship collisions with stationary infrastructure using AIS data and a ship manoeuvring simulator2021In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 235, article id 109396Article in journal (Refereed)
    Abstract [en]

    The study presents a methodology that uses AIS data and a ship manoeuvring simulator to simulate and analyse marine traffic schemes with regard to risks for accidents. An event identification method is presented, which is needed for the accident scenario part of the methodology. This is based on AIS data, where the Great Belt VTS area was used to verify the methodology. Three events that could result in ship-bridge allisions were modelled and simulated in the simulator: drifting ship, sharp turning ship and miss of turning point. The Monte Carlo method was used to perform large number of simulator runs, including a parameter sensitivity analysis. The probability of a ship allision against the Great Belt Bridge was calculated to be 0.007. Analysis of the ship-bridge allision cases was shown to be dominated by the event drifting ship. This event has a relatively low kinetic energy at the impact, and the expected allision energy for a 1,000-year allision corresponds to a 178 m tanker with 57,870 DWT and ship speed 14.6 knots. Finally, this study presents a mitigation analysis, which shows how the probability of allisions can be reduced by reducing the ship speed or altering the traffic separation scheme. © 2021 The Authors

  • 37.
    Irannezhad, Mohsen
    et al.
    Chalmers University of Technology, Sweden.
    Bensow, Rickard E.
    Chalmers University of Technology, Sweden.
    Kjellberg, Martin
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Eslamdoost, Arash
    Chalmers University of Technology, Sweden.
    Comprehensive computational analysis of the impact of regular head waves on ship bare hull performance2023In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 288, article id 116049Article in journal (Refereed)
    Abstract [en]

    This paper focuses on investigating the impact of waves on ship hydrodynamic performance, enhancing our understanding of seakeeping characteristics and contributing to advanced ship and propeller design. It examines the resistance, motions, and nominal wake of the KVLCC2 bare hull, which is free to surge, heave, and pitch, in both calm water and regular head waves using a RANS approach. The research reveals a substantial dependency of the wake on grid resolution, particularly in calm water and shorter waves, while motions and resistance display a weaker dependency. The computed nominal wake is compared against towing tank SPIV measurements. Utilizing Fourier analyses and reconstructed time series, the study examines correlations among various factors influencing the bare hull’s performance in waves. The axial velocity component of the wake in waves demonstrates significant time variations, mainly driven by higher harmonic amplitudes. This dynamic wake is influenced by instantaneous propeller disk velocities due to hull motions, orbital wave velocities, boundary layer contraction/expansion, bilge vortex and shaft vortex dynamics. The wake distribution at the propeller plane not only differs significantly from the calm water wake in longer waves but also exhibits notably larger time-averaged values (up to 21%). 

  • 38.
    Irannezhad, Mohsen
    et al.
    Chalmers University of Technology, Sweden.
    Bensow, Rickard E
    Chalmers University of Technology, Sweden.
    Kjellberg, Martin
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Eslamdoost, Arash
    Chalmers University of Technology, Sweden.
    Towards Uncertainty Analysis of CFD Simulation of Ship Responses inRegular Head Waves2021In: Proceedings of the 23rd Numerical TowingTank Symposium, NuTTS 2021, 2021Conference paper (Refereed)
    Abstract [en]

    Ship hydrodynamic performance prediction in waves is a common practice in the early stages of the ship design process as the interaction between the ship and waves may adversely affect the hydrodynamic responses of the ship in comparison to calm water. Various well­established numerical and experimental methods are often utilized for prediction of ship performance in waves. Although the model tests are expensive and time­consuming, a high level of accuracy is often achieved in such experiments. On the other hand, with respect to the increased computational power, prediction of ship performance in waves by the numerical methods based on Computational Fluid Dynamics (CFD) techniques are gradually acquiring more popularity. However, the validity of the incorporated discretization schemes and modelling assumptions in these state­of­the­art CFD methods are often overlooked and the method accuracy is mainly assessed through the validation of the results based on the respective model test data. Validation as an engineering exercise aims to show that the right equations are solved, while verification (mathematical exercise) is required to demonstrate that equations are solved right [1]. The eventual objective of this research is to perform verification and validation exercises of a ship performance prediction in regular head waves using CFD, whereas in this paper, the working progress is presented which may be subjected to significant revisions. To this end, extensive attempts have been made to investigate numerical wave propagation without the presence of the hull. Ship responses in waves are significantly influenced by the wave excitation forces. Therefore, not only high level of accuracy is required for the simulation of the numerical waves, but also quantification of the numerical uncertainties are of a great importance. This becomes even more challenging when the ship hydrodynamic responses, such as motions and added resistance in waves, exhibit dependencies on wave steepness. In this paper, the main focus of such uncertainty analyses is on the systematic grid convergence study.

  • 39.
    Irannezhad, Mohsen
    et al.
    Chalmers University of Technology, Sweden.
    Eslamdoost, Arash
    Chalmers University of Technology, Sweden.
    Kjellberg, Martin
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Bensow, Rickard
    Chalmers University of Technology, Sweden.
    Investigation of ship responses in regular head waves through a Fully Nonlinear Potential Flow approach2022In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 246, article id 110410Article in journal (Refereed)
    Abstract [en]

    In this study, the hydrodynamic performance of a ship in terms of motions and resistance responses in calm water and in regular head waves is investigated for two loading conditions using a Fully Nonlinear Potential Flow (FNPF) panel method. The main focus is understanding the ship responses in a broad range of operational conditions. Comprehensive analyses of the motions and their correlation with the wave making resistance including their harmonics in waves are presented and compared against experimental data. The predicted motions compare well with experimental data but the resistance prediction is not quite as good. The natural frequencies for heave and pitch are estimated from a set of free decay motion simulations in calm water to provide a better insight into the ship behavior near resonance conditions in waves. Interestingly, in addition to the well known peak in the added wave resistance coefficient around wave lengths close to one ship length, a secondary peak is detected in the vicinity of wave lengths with half the ship length. © 2022 The Authors

  • 40.
    Kanchiralla, Fayas Malik
    et al.
    Chalmers University of Technology, Sweden.
    Brynolf, Selma
    Chalmers University of Technology, Sweden.
    Olsson, Tobias
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Ellis, Joanne
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Hansson, Julia
    Chalmers University of Technology, Sweden; IVL Swedish Environmental Research Institute, Sweden.
    Grahn, Maria
    Chalmers University of Technology, Sweden.
    How do variations in ship operation impact the techno-economic feasibility and environmental performance of fossil-free fuels?: A life cycle study2023In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 350, article id 121773Article in journal (Refereed)
    Abstract [en]

    Identifying an obvious non-fossil fuel solution for all ship types for meeting the greenhouse gas reduction target in shipping is challenging. This paper evaluates the technical viability, environmental impacts, and economic feasibility of different energy carriers for three case vessels of different ship types: a RoPax ferry, a tanker, and a service vessel. The energy carriers examined include battery-electric and three electro-fuels (hydrogen, methanol, and ammonia) which are used in combination with engines and fuel cells. Three methods are used: preliminary ship design feasibility, life cycle assessment, and life cycle costing. The results showed that battery-electric and compressed hydrogen options are not viable for some ships due to insufficient available onboard space for energy storage needed for the vessel’s operational range. The global warming reduction potential is shown to depend on the ship type. This reduction potential of assessed options changes also with changes in the carbon intensity of the electricity mix. Life cycle costing results shows that the use of ammonia and methanol in engines has the lowest life cycle cost for all studied case vessels. However, the higher energy conversion losses of these systems make them more vulnerable to fluctuations in the price of electricity. Also, these options have higher environmental impacts on categories like human toxicity, resource use (minerals and metals), and water use. Fuel cells and batteries are not as cost-competitive for the case vessels because of their higher upfront costs and shorter lifetimes. However, these alternatives are less expensive than alternatives with internal combustion engines in the case of higher utilization rates and fuel costs.

  • 41.
    Kim, Keunjae
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Leer-Andersen, Michael
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Werner, Sofia
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Roughness Effects on Ship Design and Operation2021In: Part of the Lecture Notes in Civil Engineering book series (LNCE, volume 63), Springer Science and Business Media Deutschland GmbH , 2021, p. 186-204Conference paper (Refereed)
    Abstract [en]

    Hull surface condition plays an important role for ships performances for new-built ships as well as ships in operation since the drag penalties due to hull roughness are substantial. It is a standard practice that ship design is based on performance evaluation by model testing of ship models with hydrodynamically smooth surface and the increase of resistance for new build condition is added by roughness correlation allowance based on empirical formula. Surface roughness effects beyond the new build condition are seldom considered in the design process. The question is whether hull roughness affects the flow characteristics to such extend that it influence with the resulting design. This is especially important for propellers or energy saving devices which are operating around the stern of the ship where the roughness effects on flow characteristics are most pronounced. This paper will discuss some practical questions related to the effect of hull roughness, both in terms flow characteristics, power increase and impact on ship design and operational practice. 

  • 42.
    Kim, Keunjae
    et al.
    SSPA Sweden AB, Sweden.
    Leer-Andersen, Michael
    SSPA Sweden AB, Sweden.
    Werner, Sofia
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department. SSPA Sweden AB, Sweden.
    Orych, M.
    FLOWTECH International AB, Sweden.
    Choi, Y.
    Daewoo Shipbuilding and Marine Engineering Co Ltd, South Korea.
    Hydrodynamic optimization of pre-swirl stator by CFD and model testing2013In: International Shipbuilding Progress, ISSN 0020-868X, E-ISSN 1566-2829, Vol. 60, no 1-4, p. 233-276Article in journal (Refereed)
    Abstract [en]

    With environmental concerns becoming one of the most important issues facing the shipping/ship-building industry today, SSPA has witnessed strong demand for the development of energy saving devices (ESD). SSPA anticipates that the demand will be greater to respond to new requirements set by the IMO regulation on energy efficient design index (EEDI). SSPA has been involved in many joint research projects in developing energy saving solutions. Daewoo Shipbuilding and Marine Engineering Co. Ltd. (DSME) has developed several ESDs in cooperation with SSPA, where SSPA has tested most of the ESDs designed by DSME over the last 10 years. The pre-swirl stator (PSS) is a device mounted on the stern boss just upstream of the propeller (see Fig. 6 or Fig. 33). It is designed to generate pre-swirl flow to the propeller in order to gain a favorable interaction with the propeller that improves the propulsive efficiency and results in a power reduction. This paper is a full description of one of the developments of PSS from the early design stage, optimization phase, and confirmation by model tests to validation through sea trial tests. 

  • 43.
    Kjellberg, Martin
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Gerhardt, Frederik
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Werner, Sofia
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Sailing in waves: A numerical method for analysis of seakeeping performance and dynamic behavior of a wind powered ship2022In: SNAME 24th Chesapeake Sailing Yacht Symposium, CSYS 2022, Society of Naval Architects and Marine Engineers , 2022Conference paper (Refereed)
    Abstract [en]

    Before the background of the internationl Maritime Organization's 2050 emission reducation targets, the largest sailing ship in the world is currently being developed in Sweden. This wind powered car carrier, called Oceanbird, will have four 80-metre-high wing sails targeting CO2savings in the order of 90%. The prediction and analysis of the seakeeping performance of such a ship is of importance, not only in terms of sailing dynamics, but also when it comes to the structural design of the rig. To this end, a numerical method for predicting a ship's motions and loads on its rigid wing sails is described in this paper and a demonstration of how the method can be used to obtain such loads is presented. The numerical method is based on an unsteady 3D fully nonlinear potential flow hydrodynamic model coupled with a hybrid 2D RANS/3D lifting-line aerodynamic model. Simulations in a seaway with short-crested irregular waves and corresponding wind conditions are conducted, resulting in time histories of the aerodynamic and inertial forces acting on the rig. Possible applications of the method include fatigue analysis of the wing sails, where the accumulated fatigue damage over the lifespan of the rig structure depends on the sum of aerodynamic forces and motion induced inertial forces. Other potential applications include sail dynamics, parametric roll, sheeting strategies and appendage configuration studies. 

  • 44.
    Kjellsdotter Ivert, Linea
    et al.
    VTI, Sweden.
    Santén, Vendela
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Merkel, Axel
    VTI, Sweden.
    Wide, Per
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Svenska hamnars roll i en cirkulär ekonomi2023Report (Other academic)
    Abstract [en]

    För att Sverige ska kunna nå målet om att bli ett av världens första fossilfria välfärdsländer krävs en omställning till ett fossilfritt transportsystem såväl som till en cirkulär ekonomi. Sjöfart har potential att matcha de behov som en ökad cirkulär ekonomi ställer och är ett energieffektivt trafikslag. Syftet med rapporten är att förstå hur sjöfart kan nyttjas i ökad utsträckning för att transportera cirkulära produkter och material och hur hamnen kan skapa mervärde i utveckling av cirkulära logistiklösningar. Metoderna som använts är: litteraturstudier, workshops och fallstudier. Rapporten identifierar cirkulära produkter och material med potential att lyfta sig i avfallstrappan och där det är lämpligt att nyttja sjöfart för transport i det cirkulära logistiksystemet. Det handlar om muddermassor, jordmassor, mineralavfall, träavfall, plastavfall, uttjänta däck, uttjänta textilier, sorterade och återvunna textilier, planglas, spillolja och flygaska. Hamnens roll vid hantering av cirkulära material studerades mer specifikt för massor, dissolvingmassa baserad på återvunna textilier, matrester och etanol. Det blev tydligt att hamnen kan skapa värde i form av lagring, konsolidering, lossning och lastning av containrar samt vara en logistiknod som erbjuder omlastningsmöjligheter mellan olika trafikslag. Hamnen känner till de lokala förutsättningarna för effektiva logistikupplägg och är en central kugge i nya aktörsnätverk. Rapporten redovisar även en beskrivning av två cirkulära logistiklösningar med involvering av sjöfart som utvecklats och utvärderats under projektet. Det handlar dels om en demonstration av en sjötransport med kalkstabiliserad lera, dels om framtagning av beslutsunderlag för investering av en tilltänkt sorteringsmaskin av planglas i vilket logistikupplägg från ett antal olika hamnar förslogs och miljöberäkningar genomfördes.

  • 45.
    Knudsen, Stig
    et al.
    DTU Technical University of Denmark, Denmark.
    Marimon Giovannetti, Laura
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Legarth, Brian Nyvang
    DTU Technical University of Denmark, Denmark.
    Walther, Jens Honoré
    DTU Technical University of Denmark, Denmark.
    Dynamic Fluid Structure Interaction of NACRA 17 Foil2024In: Journal of Marine Science and Engineering, E-ISSN 2077-1312, Vol. 12, no 2Article in journal (Refereed)
    Abstract [en]

    The NACRA 17 is a small foiling catamaran that is lifted out of the water by two asymmetric z-foils and two rudder elevators. This paper investigates how foil deflection affects not only foil performance but overall boat behaviour using a numerical Fluid Structure Interaction (FSI) model. The deformations are solved with a solid model based on the Finite Element Method (FEM) and the flow is solved with a Reynolds Average Navier-Stokes (RANS) based Finite Volume Model (FVM). The models are strongly coupled to allow dynamic FSI simulations. The numerical model is validated by comparing it to an experimental campaign conducted at the RISE SSPA Maritime Center in Sweden.Validation shows reasonable agreement, but the model can only be considered validated for some rake angles. The large deformation of the foils is found to have a profound effect on the performance of the foils and therefore of the overall catamaran. Turbulence transition and boat speed are found to affect foil forces and, in turn, deformation. Dynamic response of the foils during boat motion as exposed to waves is investigated and finally the full boat hydrodynamic is simulated by including both foils and the rudders in various scenarios.

  • 46.
    Kontos, S
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Lundbäck, Olov
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Kjellberg, Martin
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Wilske, E
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Werner, Sofia
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Manoeuvre simulations in design process of wind powered vesselConference paper (Other academic)
    Abstract [en]

    Wind propulsion systems (WPS) are one of the most promising technologies for ship propulsion that can radically reduce greenhouse gas emissions. However, attention must be paid to the additional transversal forces and yaw moments connected to a wind propulsion system, as it can affect the manoeuvring and seakeeping performance of a ship. This paper demonstrates how time-domain simulations can be utilised to assess the manoeuvrability of a wind powered vessel to support the decision making, from the early design stage, all the way to testing the control systems, design of Human Machine Interface (HMI) and developing crew guidelines and training. The manoeuvre simulations are carried out with SSPA’s six degree of freedom inhouse code, SEAMAN-Winds. We present firstly a validation against manoeuvring model tests of a wind powered ship, where the wind propulsion units are represented by pulling fans. VPP calculations, which are commonly used in the early design phase, can predict the rudder angle required to balance the side force and yaw moment from the wind propulsion system. However, such steady-state computations provide no information on how robust this balance is when dynamic effects are present (e.g., wind gusts) and whether the balance can be regained if it has been momentarily lost. Therefore, time-domain simulations are shown to be useful to assess whether a ship can sail safely close to the limits of its VPP polars. Furthermore, it is demonstrated how mariners operating a real-time manoeuvre simulation tool can be utilised to increase the proof-of-concept, assess the HMI design, and for crew training.

  • 47.
    Korkmaz, Kadir Burak
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Kim, Keunjae
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Liefvendahl, Mattias
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Werner, Sofia
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Orych, Michal
    FLOWTECH International AB, Sweden.
    A Validation Study of Full-Scale CFD Simulation for Sea Trial Performance Prediction of Ships2023Conference paper (Refereed)
    Abstract [en]

    Shipping is a critical component of global trade but also accounts for a substantial portion of global greenhouse gas emissions. Recognising this issue, the International Maritime Organisation (IMO) has implemented new measures aimed at determining the energy efficiency of all ships and promoting continuous improvements, such as the Energy Efficiency Existing Ship Index (EEXI). As Computational Fluid Dynamics (CFD) can be used to calculate the EEXI value, RISE-SSPA1 and Flowtech have developed a CFD-based method for predicting full-scale ship performance with SHIPFLOW v7.0, which meets the new requirements of IMO. The method is validated through an extensive comparison study that examines the delivered power and propeller rotation rate between full-scale CFD predictions and high-quality sea trials using 14 common cargo ships of varying sizes and types. The comparison between the CFD predictions and 59 sea trials shows that both delivered power and RPM can be predicted with satisfactory accuracy, with an average comparison error of about 4% and 2%, respectively. The numerical methods used in this study differ significantly from the majority of the state-of-the-art CFD codes, highlighting their potential for future applications in ship performance prediction. Thorough validation with a large number of sea trials is essential to establish confidence in CFD-based ship performance prediction methods, which is crucial for the credibility of the EEXI framework and its potential to contribute to shipping decarbonisation.

  • 48.
    Korkmaz, Kadir Burak
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department. Chalmers University of Technology, Sweden.
    Werner, Sofia
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Bensow, Rickard
    Chalmers University of Technology, Sweden.
    Investigations on experimental and computational trim optimisation methods2023In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 288, article id 116098Article in journal (Refereed)
    Abstract [en]

    Shipping is vital for global trade but also emits significant greenhouse gases. To address this issue, various measures have been proposed, including improved ship design, alternative fuels, and improved operational practices. One such cost-effective operational measure is trim optimisation, which involves operating the ship at the hydrodynamically optimal forward and aft draughts. This study focuses on investigating the trim trends of a RoPax vessel using experimental fluid dynamics (EFD) and computational fluid dynamics (CFD) methods. The trim trends are derived in resistance and self-propelled modes. Multiple CFD methods are examined, along with different extrapolation techniques for experimental results. Uncertainty assessment is conducted for the experimental data, and a verification and validation study is performed. Furthermore, the predictions are compared with real operational data. The findings reveal that determining trim trends solely in towed mode is inadequate due to the profound influence of the operating propeller. Some of the investigated CFD methods demonstrate good agreement with the model test results in self-propelled mode, while others exhibit limitations. By selecting appropriate models and configurations, this study demonstrates that trim trends can be determined with sufficient precision, as evidenced by the comparison between ship operational data and predictions from EFD and CFD methods. 

  • 49.
    Korkmaz, Kadir Burak
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department. Chalmers University of Technology, Sweden.
    Werner, Sofia
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Bensow, Rickard
    Chalmers University of Technology, Sweden.
    Scaling of wetted-transom resistance for improved full-scale ship performance predictions2022In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 266, article id 112590Article in journal (Refereed)
    Abstract [en]

    Determining a ship's propulsive power is a critical stage in the design phase in which the evaluation of the stern plays a crucial role. Different flow regimes can be observed depending on the position and shape of the transom. This paper investigates the wetted-transom flow characteristics and their implications on the 1978 ITTC Performance Prediction Method. In the case of flow separation, such as the wetted-transom flow, the current ITTC-78 procedure does not provide an alternative method. Therefore, two alternative methods were proposed based on the investigations of CFD computations on seven hull forms. The firstly proposed method is a combined EFD&CFD method called the two form factor method. It requires CFD computations in model and full-scale, and it can handle any case of flow separation, including the wetted-transom flow. The second proposed method is an empirical correction formula for the hulls with a wetted-transom flow. Finally, the full-scale speed-power relations between the speed trials and the full-scale predictions from the two alternative methods and the standard ITTC-78 method were presented. It is observed that the two suggested methods considerably improve the correlation between the predictions and the speed trials. © 2022 The Author(s)

  • 50.
    Korkmaz, Kadir Burak
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department. Chalmers University of Technology, Sweden.
    Werner, Sofia
    RISE Research Institutes of Sweden, Safety and Transport, Maritime department.
    Bensow, Rickard
    Chalmers University of Technology, Sweden.
    Verification and validation of CFD based form factors as a combined CFD/EFD method2021In: Journal of Marine Science and Engineering, E-ISSN 2077-1312, Vol. 9, no 1, article id 75Article in journal (Refereed)
    Abstract [en]

    Predicting the propulsive power of ships with high accuracy still remains a challenge. Well established practices in the 1978 ITTC Power Prediction method have been questioned such as the form factor approach and its determination method. This paper investigates the possibility to improve the power predictions by the introduction of a combined CFD/EFD Method where the experimental determination of form factor is replaced by double body RANS computations. Following the Quality Assurance Procedure proposed by ITTC, a best practice guideline has been derived for the CFD based form factor determination method by applying systematic variations to the CFD set-ups. Following the verification and validation of the CFD based form factor method in model scale, the full scale speed-power-rpm relations between large number of speed trials and full scale predictions using the CFD based form factors in combination with ITTC-57 line and numerical friction lines are investigated. It is observed that the usage of CFD based form factors improves the predictions in general and no deterioration is noted within the limits of this study. Therefore, the combination of EFD and CFD is expected to provide immediate improvements to the 1978 ITTC Performance Prediction Method. © 2021 by the authors. 

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