Abstract: The small-scale fire whirl is produced by two split cylinders with gap size 7.6 cm. The axial velocities at different heights (4, 6, 8, 10, 12 cm) are measured by particle image velocimetry method. It is found that the axial velocity decreases with radial distance and the maximum axial velocity is obtained at the centerline of the fire whirl. The centerline temperature is obtained by thermocouples and the centerline temperature is almost constant in the continuous flame zone. According to the data of velocity and temperature, the mass flow rate of small-scale fire whirl in different heights is calculated and the results show that the mass flow rate increases with flame height.

Key words: small-scale, fire whirl, flame temperature;axial velocity, mass flow rate