Thermal Radiation from Fire Whirls: Revised Solid Flame Model

Abstract

The conventional solid flame model for calculating the radiation from pool fires involves a constant flame surface emissive power. In this paper, in terms of the fact that the flame shape of fire whirl can be simulated by combination of a cylinder and a cone, a new formula is proposed to characterize the vertical profile of the flame surface emissive power of fire whirl, by which a revised solid flame model is presented for calculating the radiant heat flux from the flame, in the horizontal and vertical directions. In comparison to the conventional solid flame model, the revised model agrees better with the experimental data of radiant heat flux, especially for heat release rates below a certain critical range. By the revised model it is indicated that the profile of radiant heat flux significantly varies with the distance away from the pool centerline. The effect of plume radiation and flame pulsation are suggested to be considered for further improving the radiation model of fire whirl.