Investigation on heat transfer characteristics of spiculate lamilloy internal surfaces

Experiment was carried out to analyze the heat transfer characteristics of the inner surfaces of a kind of lamilloy configuration by using narrow-band transient liquid crystal technique.In this research,the ratio of hole pitch to impingement hole diameter(S/D) is 3.2,4.5,5.9,and Reynolds numbers range from 10 000 to 40 000.This paper also compared with traditional lamilloy model to analyze the heat transfer mechanism.The result shows that: heat transfer coefficient of the surfaces increases when Re becomes greater,and gradually decreases when the holes pitch becomes wider.The mathematics fit formulas of the Nu with respect to Re and S/D has also been given.