Transient radiative heat transfer of pool fires based on large eddy simulation

doi:10.16265/j.cnki.issn1003-3033.2022.04.010

Abstract

Abstract:

In order to explore transient radiative heat transfer characteristics of pool fires, a combustion model of methanol fire was developed based on large eddy simulation, and non-gray radiative properties of combustion gases were simulated by adopting accurate weighted sum of gray gases (WSGG) model. Then, transient characteristics of temperature, velocity, species concentration and radiative energy were investigated. The results show that gas temperature varies in a periodical pattern, during which high temperature gases form above pool surface, then rises, expands and spreads in cycles, with its velocity increasing first and then decreasing during rising process. Due to this factor, radiative feedback at surface shows an oscillating behavior, and radiative heat flux at center varies between -17 and -7 kW/m² drastically, which decreases along radial direction. Moreover, probability density of heat fluxes at surface spreads like a triangle. As the ground is far away from fire and partially blocked by tanks, its heat flux is one order of magnitude smaller that of pool surfaces.

Key words: pool fire, large eddy simulation, methanol fire, radiative heat transfer, transient radiative heat flux

SUN Yujia. Transient radiative heat transfer of pool fires based on large eddy simulation[J]. China Safety Science Journal, 2022, 32(4): 65-71.

Figures/Tables 9

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