Flow field characteristics of fire plume in different restricted forms based on PIV

doi:10.16265/j.cnki.issn1003-3033.2020.06.020

Abstract

Abstract: In order to explore effects of different restricted forms on flow field of fire plume, fine thermocouple and PIV technologies were used to monitor fire plume's height, temperature and flow field of diffusion burner in free space, side wall space and corner space, and then flow field characteristics in different restricted forms were studied. The experimental results show that when dimensionless source power Q^* is less than 1.5, dimensionless flame height L_f/D increases linearly which will become steady approximately when Q^* exceeds 1.5. Lateral velocity in different restricted spaces all conform to approximate Gaussian distributions, and sidewall space and corner space cause a certain deviation of flame center. Vortex diameter is between 3.5 and 8 cm at Q^* is 1.982, and its size gradually increase along with increase of side wall surface because vortex will fall off, which will release a lot of heat in a short time and exerts a stretching impact on fire plume. As a result, combustion reaction of fire is promoted, and then a larger vortex is generated.

Key words: particle image velocimetry (PIV), resticted forms, flow field of fire plume, temperature field, vortex

CLC Number:

X932

ZHANG Wei, ZHANG Ying, LI Changwei, YUAN Dachao. Flow field characteristics of fire plume in different restricted forms based on PIV[J]. China Safety Science Journal, 2020, 30(6): 135-141.

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