Study on the Influence of Air-inlet Width on Fire Whirls Combustion Characteristic

The size of air-inlets in fire scene influences the air entrainment, and the power of air entrainment has an obvious effect on the formation and the combustion characteristic of fire whirls. In order to study the air-inlet influence on fire whirl combustion characteristic, the experiment in this work used the fire whirl generator with six free-setting horizontal openings to simulate different size of air-inlets in fire scene. The results show that the forming time of fire whirls decreases firstly and increases afterward with the increase of air-inlet width, and accordingly the intensity and stability increase firstly and then decrease. When the air-inlet widths are 20∼30 cm, the fire whirls intensity and stability is superior to others, the forming time is the shortest and the lasting time is the longest. In addition, this paper explains preliminarily the reason for the influence that air-inlet width makes on fire whirls combustion characteristic.