【摘 要】
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Fire scenarios of urban long straight underground tunnel have been studied.The large eddy simulation method is used to calculate the length of near field of fire source,which is related to smoke contr
【机 构】
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Beijing University of Technology
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Fire scenarios of urban long straight underground tunnel have been studied.The large eddy simulation method is used to calculate the length of near field of fire source,which is related to smoke control on fire scenario.The length is a key factor to study long and narrow spaces fire from the CFD numerical simulation method.Effects of long and narrow spaces section size,fire source power and thermal release efficiency have been taken into account to determine the full propagation distance of smoke.Several different sizes of long and narrow spaces and fire powers have been analyzed to determine the length of near field of fire source.It is shown that the length of near field of fire source is influenced primarily by the width of long and narrow spaces,the heat release rate of fire,the effective ceiling height,the distance form fire.Results show that,for t2 ultra-fast fire,power of which is 15 MW,the length of near field of fire source is 115 m.It has also been found that the length of near field of fire source is almost not affected by tunnel size and fire source power.A formula for making realistic estimates of the length of near field of fire source,based on these results,is presented.By comparing the derivation formula for fire development and the numerical simulation calculation fire model by PHOENICS software,it could be concluded that fire source development had a great effect on the length of near field of fire source.
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