A study on relationship between burning rate and flame height of internal fire whirls in a vertical shaft model

Relationship between internal fire whirls generated in a vertical shaft model was studied. A vertical shaft model of height 145 cm was constructed. Four fuels including methanol, ethanol, propanol, and gasoline of different pool sizes were used. Ventilation was provided from a sidewall for onsetting internal fire whirl. In the experiments, the flame height and mass loss rate of fuel while burning the pool fires were observed to increase at the same time. A linear correlation between flame height and mass fuel burning rate can be found for different liquid fuels. A parameter α, which describes the burning rate, calorific value, and the pool size of liquid fuel, was used to develop the correlation between the burning rate and flame height. The flame height was found to be linearly correlated with α. However, the normalized average flame height was found to be roughly constant with different values of α.