Experimental and theoretical study of combustion and aerothermodynamic effects on the flame structure from wind-driven rectangular fires

This work provides a comprehensive model for global morphology parameters of flame structure of turbulent diffusion flames in wind-driven rectangular burner fires. Five flame morphology parameters were configured by using the image from CCD cameras and CFD calculations, demonstrating for the first time the image corresponds to a mixture fraction. The unique physics-based similarity correlations for the combustion were proposed to predict the morphology parameters of flame structures in terms of a characteristic length scale. The reliability of the current physical model and new correlations was validated by comparing it with other literature data. One important result of this paper is that the source size does not affect the flame morphology if a Froude number based on the source size is greater than a fraction of the ratio of the flame length at no wind to the source size. Subsequently, based on top hat similarity of the flow profiles, a phenomenological integral combustion model including momentum and continuity equations was also established and the results were compared well with the experimental data and the new correlations. Finally, CFD numerical modeling and large-scale experimental data in the literature were employed to verify the applicability of the present model for large-scale pool fire combustion. •Flame morphology of rectangular fires in cross winds is examined.•Scaling of flame structure of rectangular fires in cross winds is proposed.•Integral and CFD modeling of rectangular fires in cross winds are presented.