火旋风是林火蔓延过程中的特殊火行为现象,与树冠火和飞火关系密切.火旋风的发生机理在于旋转涡的生成和发展.构建室内火旋风模拟发生装置是当前火旋风研究的常用方法.在室内模拟试验中,红外热像和热电偶可用于测量火焰温度,高速摄影、三维激光多普勒和皮托管用于测量火旋风的转速.基于室内实验数据,可构建模拟火旋风发生发展的三维模型.
Fire whirl is a special fire behaviour that occurs in forest fire,and closely linked with crown fire and spot fire.Its generation mechanisms lie in the generation and development of rotating vortex.Establishing fire whirl simulation devices is one of the common research methods.In laboratory simulation tests,infrared thermography and thermocouple are adopted to measure flame temperature,while high-speed photography,three-dimensional laser Doppler,and Pitot tubes are used to measure fire whirl rotating speed.On the basis of experimental data,three-dimensional fire whirl models can be constructed.