An experimental study and mathematical quantification of buoyant turbulent flame morphology under the coupling effects of inclined surfaces and crossflows

Abstract

This paper investigates the flame morphology of buoyant turbulent propane flames under the coupling effects of inclined surfaces and horizontal crossflows. Horizontal crossflows were generated by wind tunnels faced to the flame on the inclined surface. The tilt angle, length, height, and attachment length of the flame were investigated with heat release rates of 6.15–18.45 kW, crossflow velocities of 0–1.00 m/s, and slope angles of 0–40°. As the results show, the relationship between the effects of inclined surfaces and crossflows on the different flame morphology parameters is different. As the crossflow velocity increases, the flame tilt angle will increase. However, the increment rate of the flame tilt angle will be limited by the inclined surface as the crossflow velocity gradually increases. The flame length is more susceptible to the crossflow than the inclined surface under coupling effects, which decreases and then increases with increasing crossflow velocity. As the crossflow velocity and slope angle increase, the flame height decreases. Meanwhile, the flame attachment length monotonically increases. The inclined surface and crossflow have a synergistic effect on the flame height and attachment length. New global correlations for flame morphology parameters were obtained based on the wind Froude number, the dimensionless heat release rate, the propane to air density ratio, and the cosine of the slope angle. The model predictions agree well with the data from this experiment and previous research.