A mathematical model for burning rate of n-heptane pool fires under external wind conditions in long passage connected to a shaft

A set of experiments was conducted to study the influence of external wind on burning rates of n-heptane pool fires in a long passage connected to a shaft. The competitive effect led by the external wind and the stack effect induced by fire significantly influenced the burning rate of n-heptane pools. Results show that there is one critical wind velocity for certain pool size. While the external wind velocity is lower than the critical velocity, the burning rate at the quasi-steady stage does not change with the wind velocity. As the external wind velocity approaches the critical velocity, the burning rate at the quasi-steady stage decreases as the heat feedback from the boundaries is significantly reduced. Once the external wind velocity exceeds the critical velocity, the burning rate increases with wind velocity, and under the same wind velocity its value is approximately 2 times of the one in open space. Moreover, it is found that the average temperature rise inside the shaft has strong linear correlation with burning rate while the stack effect takes place, otherwise it remains as the ambient temperature.