Burning dynamics and in-depth flame spread of wood cribs in large compartment fires

Wood cribs pervade the fire research literature as chosen fuel load for testing within built environment. As such, underpinning knowledge of behaviour in compartments was developed from experiments using wood small compartments. Despite apparent incomparability porous fuel-beds such to real solid fuels environment, role mass transfer number (“B-Number”) defining compartment dynamics has received little attention. In case large open-plan compartments, burning processes are strongly dependant on relationship nature and geometry. To address these limitations, physical in-depth external a spreading crib examined. A theory couple is proposed analogised into classical “Emmons problem”, leading definition total crib. Comparing against data large-scale experiment shows that approximates steady-state two regimes: fuel-bed-controlled regime momentum-controlled regime. The occurs when spread rates governed by internal crib, therefore defined This characterised travels or grows slowly, with heat fluxes. fully-developed fluxes very large. Burning controlled residence time, complex transport associated momentum-driven flows Transitions driven accelerations flame rate along surface an additional energy input mechanism used raise It hypothesised mechanisms numbers, non-charring plastics, diverge significantly cribs, extrapolating test fires must be done extreme caution. Thus, important unavoidable consideration studying