Experimental Investigation and Scaling Analysis of Turbulent Diffusion Flame Behavior over Inclined Surfaces Under Cross-Slope Wind

This study establishes an experimental platform consisting of an adjustable inclined surface and a cross-slope wind system. Turbulent diffusion flames are investigated by examining the variation characteristics of flame morphology under slope angles of 10–40°, cross-slope wind velocities of 0.8–2.0 m/s, and heat release rates of 15.38–61.50 kW. The results show that variations in slope angle change the components of buoyancy in the normal and tangential directions. The normal component influences the lifting of the flame perpendicularly to the slope, while the tangential component, together with differences in air entrainment on both sides of the flame, promotes flame inclination and spreading along the slope surface. The cross-slope wind enhances the horizontal stretching and attachment tendency of the flame through inertial shear, while simultaneously suppressing flame height and its development along the slope. The coupled effects of these factors cause the flame morphology to gradually transition from a nearly vertical state to an attached state. Based on dimensionless analysis, empirical correlations of flame morphology parameters are established by introducing the cross-slope wind Froude number, dimensionless heat release rate, the density ratio of propane to air, and a slope function. Within the experimental range of this study, the data under various conditions show good collapse and correlation under the selected dimensionless parameters.