Experimental study on the mass burning rate and flame tilt angle of annular pool fires under cross air flow

Annular pool fire is a common type of accident that occurs in the early stages of a liquid fuel leakage incident. It often results in a large pool fire that can be challenging to control if not properly managed. This paper investigates the evolution of the mass burning rate and flame tilt angle of medium-scale annular pool fires (0.3 m similar to 0.6 m) with different inner and outer diameter ratios (D-in/D-out) under cross air flow speeds ranging from 0 to 5 m/s through experiments. It has been found that the mass burning rate of an annular pool fire is positively correlated with the cross air flow. With a maximum error of about 20%, the new burning rate model very closely matched the data from the literature. With an increase in cross air flow, the flame tilt angle gradually increases. Under the same cross air flow rate, the flame tilt angle decreases as the D-in/D-out ratio of the annular pool increases. In this paper, a prediction model for flame tilt angle is established, considering the influence of the inner and outer diameters of the annular pool. And after comparing with reference data, it was found the maximum error is about 15%.