Effect of Opening Geometry on the Heat Transfer Characteristics for External Flames Impinging on an Exterior Wall

Abstract

The heat transfer characteristics of external flames impinging on an exterior vertical wall have been investigated experimentally. The external flame was produced by the combustion of liquid fuel n-heptane in a compartment and then ejected from the compartment opening. The effect of opening geometry on the heat flux distribution is studied. Results indicate that the opening aspect ratio, which is defined as the ratio of opening height to width, has great influence on the heat flux distribution on the exterior wall. With increasing the opening width, the external flame inclines to the wall side and becomes shallower, which improves the heat transfer to the wall. A correlation is developed for correlating the heat flux to the flame height.

Keywords:

• flame impingement
• opening geometry
• heat transfer
• n-heptane
• exterior wall

Acknowledgments

This work was supported by the National Basic Research Program of China (973 Program; 2012CB719701) the National Natural Science Foundation of China (No. 51206156) and the Open Project Program of State Key Laboratory of Fire Science (HZ2012-KF14). The authors thank Prof. Yiliang Chen for his instructive suggestions on the Coanda effect.

Notes

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