Numerical study of the development and angular speed of a small-scale fire whirl

The development stages of a small-scale fire whirl including the ignition, flame-rising and fully-developed whirling were successfully captured by a fire field model. Good agreements between simulation and experimental results for vertical temperature profiles and flame height were achieved. With the consideration of the interaction between the liquid and gas phases of the fuel, the radiation heat feedback towards the liquid fuel was aptly predicted. Angular velocities that govern the rotational motion of the fire whirl were evaluated based on computed data. Furthermore, the circulate motion and buoyancy force promoting the extension of flame height were characterised in numerical simulations.