Flame interaction and burning characteristics of abreast liquid fuel fires with cross wind

Abstract

To study the influence of cross wind on flame interaction and burning characteristics of two abreast liquid fuel fires, a series of burning experiments on transversely spaced heptane pools was performed. Results show that, for both cases with and without cross wind, the flame merging gradually disappears with increasing spacing between two fuel pans. With the effect of wind, air entrainment becomes easier to occur, then flame merging phenomenon disappears at a smaller fuel spacing, compared with the case without wind. For cases with the same wind velocity, the burning rate reaches the maximum value at a small spacing distance (rather than the case with attached pools), where air entrainment restriction is relatively weaker and the radiation feedback is at a higher level. Besides the influence of vertical buoyancy and horizontal wind above fuel surface, transversely spaced flames also receive pressure thrust acting on the lateral surface of the flame by each other. A theoretical model for predicting the tilt angle towards downstream direction of the cross wind, combining with the key parameters, is proposed in this study. Heskestad correlation can give a good prediction of flame length for transversely spaced pools. In fact, the flame length is directly related to the fuel evaporation rate essentially, hence, the cross wind and fuel spacing will affect the flame length by changing fuel evaporation and burning rate. The results of this study will have implications on safety distance designing and can help to increasingly understand the interaction process and mechanism of multiple pool fires from aspects of fluid flow and radiative heat feedback.