線火災上の火災旋風の発生条件と発生機構

抄録

Occurrence of fire whirl over line fire is often observed in large-scale urban and wildland fires. When a fire whirl occurs, the heat flux to the surroundings increases, leading to an increase in the rate of fire spread. If the conditions and mechanism of fire whirl are clarified, it is expected that the accuracy of fire spread rate prediction will be improved. In this study, we conducted a model experiment using a wind tunnel and examined the generation conditions and mechanism of fire whirls over line fires. We investigated the effect of wind speed and height of wind-tunnel exit on the frequency of fire-whirl generation, obtained knowledge of generation condition, measured the velocity field around fire whirl, and discussed the generation condition.