Study on critical velocity of lateral point smoke extraction tunnel fire

doi:10.16265/j.cnki.issn1003-3033.2021.03.015

Abstract

Abstract: In order to obtain dimensionless formula to calculate critical velocity of tunnel fire in lateral point smoke extraction pattern, dimensional analysis was made on relevant influencing factors of critical velocity according to π theorem and similarity theory, and a dimensionless functional relation of three influencing factors were derived. Then, numerical simulation was conducted to define quantitative relationship between critical velocity and fire heat release rate, smoke exhaust volume and distance between smoke vent and fire source. The results show that when distance between dimensionless smoke vent and fire source is less than 2.22, critical velocity increases along with increase of distance by 1/25 power, but decreases along with increase of smoke exhaust by -3/50 power. However, when it is greater than 2.22, critical velocity no longer changes with either distance or smoke exhaust. Meanwhile, with increase in heat release rate, it always rises by 1/3 power.

Key words: lateral point smoke extraction, tunnel fire, critical velocity, dimensionless, numerical simulation

CLC Number:

X932

JIANG Xuepeng, CHEN Xin'ge, GUO Kun. Study on critical velocity of lateral point smoke extraction tunnel fire[J]. China Safety Science Journal, 2021, 31(3): 105-111.

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