Wave motion of smoke in subway fire environment

Abstract

Wave motion in subway or tunnel fire is an intrinsic property of smoke. As the pressure of smoke changes with mass of certain power, a kind of linear wave equation for smoke can be derived from the conservation equations of its mass and momentum, under nearly homogeneous zone assumption. The smoke movement of 4 subway fires was simulated with Airpak. By fitting the pressure-mass functions to the simulated data, wave equations of the smoke were derived, and wave motions of smoke were thus validated. It can be seen that smoke wave is a kind of mass wave, whose velocity is inversely proportional to smoke mass, and wave of a bigger fire propagates slower.

Keywords

subway fire environment / smoke movement / wave propagation

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