Experimental investigation of cooling effectiveness of spiculate lamilloy

Five true scale spiculate lamilloys were studied to analyze the cooling effectiveness based on the former inner surfaces' heat transfer characteristics, and an experiment was tested in a large-scale, low-speed close-looped wind tunnel. The result shows that very high cooling effectiveness can be achieved by using spiculate lamilloy. The ratio of hole pitch to impingement hole diameter(S/D) and the diameter of film hole (D_out) play important roles in determining the cooling effectiveness, the smaller S/D or larger D_out means higher cooling effectiveness. The pin diameter (D_pin) has little influence on cooling effectiveness. When blowing ratio is constant, the gas velocity also has little influence on cooling effectiveness, while blowing ratio is a major influential factor to film cooling effectiveness.