An engineering CFD model for fire spread on wood cribs for travelling firesShow others and affiliations
2022 (English)In: Advances in Engineering Software, ISSN 0965-9978, E-ISSN 1873-5339, Vol. 173, article id 103213Article in journal (Refereed) Published
Abstract [en]
The temperature heterogeneity due to fire in large open-plan office compartments is closely associated with fire spread behaviour and has been historically limited to experimental investigations using timber cribs. This study explores the ability of Computational Fluid Dynamics (CFD) models, specifically the Fire Dynamics Simulator (FDS), to reproduce the results of full-scale tests involving fire spread over timber cribs for continuous fuel-beds. Mesh schemes are studied, with a fine mesh over the crib and 2 × 2 cells in the wood stick cross-section by default, this being relaxed in the surrounding regions to enhance computational efficiency. The simple pyrolysis model considers the charring phase and moisture. In application to the TRAFIR-Liège LB7 test, this calibrated “stick-by-stick” representation shows a good agreement for interrelated parameters of heat release rate, fire spread, gas phase temperature, and burn-away, a set of agreements which has not been demonstrated in previous studies. Fire spread shows relatively high sensitivities to: heat of combustion, ignition temperature, thermal inertia, radiation fraction, heat release rate per unit area, and the fuel load density. An approximately linear regression was found between the different fire modes and the thermal exposures, with “travelling” (and decaying) fires characterised by heat fluxes associated with the fire plume, while the growing fires were associated with proportionally higher heat fluxes on the horizontal surfaces of the sticks, in conditions where these receive more pre-heating. The trends in the overall HRR are more dependent on the fire spread rates than variations in the stick burning rates. © 2022 The Author(s)
Place, publisher, year, edition, pages
Elsevier Ltd , 2022. Vol. 173, article id 103213
Keywords [en]
CFD modelling, FDS, Fire spread, Travelling fires, Wood crib fire experiments, Computational efficiency, Computational fluid dynamics, Heat flux, Ignition, Mesh generation, Office buildings, Timber, Computational fluid dynamics modeling, Fire dynamics simulator, Fire experiments, Heat release, Release rate, Timber cribs, Wood crib fire, Wood crib fire experiment, Fires
National Category
Physical Geography
Identifiers
URN: urn:nbn:se:ri:diva-60047DOI: 10.1016/j.advengsoft.2022.103213Scopus ID: 2-s2.0-85135936681OAI: oai:DiVA.org:ri-60047DiVA, id: diva2:1692999
Note
Funding details: Engineering and Physical Sciences Research Council, EPSRC, EP/R029369/1; Funding details: University of Edinburgh, ED; Funding details: Research Fund for Coal and Steel, RFCS, 754198; Funding text 1: This work was carried out in the frame of the TRAFIR project with funding from the Research Fund for Coal and Steel (grant N°754198). Partners are ArcelorMittal Belval & Differdange, Liège Univ. the Univ. of Edinburgh, RISE Research Inst. of Sweden and the Univ. of Ulster. This work used the ARCHER UK National Supercomputing Service (http://www.archer.ac.uk), and the resources provided by the Edinburgh Compute and Data Facility (ECDF) (http://www.ecdf.ed.ac.uk/) and assistance of relevant administrators is acknowledged. The authors are grateful to EPSRC (grant number: EP/R029369/1) and ARCHER for financial and computational support as a part of their funding to the UK Consortium on Turbulent Reacting Flows (www.ukctrf.com). The UKCTRF Consortium benefits from the support of CoSeC, the Computational Science Centre for Research Community. Funding text 2: This work was carried out in the frame of the TRAFIR project with funding from the Research Fund for Coal and Steel (grant N°754198 ). Partners are ArcelorMittal Belval & Differdange, Liège Univ., the Univ. of Edinburgh, RISE Research Inst. of Sweden and the Univ. of Ulster. This work used the ARCHER UK National Supercomputing Service ( http://www.archer.ac.uk ), and the resources provided by the Edinburgh Compute and Data Facility (ECDF) ( http://www.ecdf.ed.ac.uk/ ) and assistance of relevant administrators is acknowledged. The authors are grateful to EPSRC (grant number: EP/R029369/1) and ARCHER for financial and computational support as a part of their funding to the UK Consortium on Turbulent Reacting Flows ( www.ukctrf.com ). The UKCTRF Consortium benefits from the support of CoSeC, the Computational Science Centre for Research Community.
2022-09-052022-09-052023-05-22Bibliographically approved