透平叶片中腔的强化冷却研究

肋粗糙表面在透平叶片冷却中已有实际应用。为更有效地提高冷却效果,在叶片内腔壁面设置肋-槽型复合粗糙元是一种有力措施(见图1)。由于在肋间加了槽,从而加强了粗糙元对流体的连续性扰动,同时换热面积也有所增加。文献1]以水和二甲苯为介质在肋-槽型复合粗糙环形通道中进行的换热和阻力试验表明:复合粗糙面的换热强度高于肋粗糙表面,而流动阻力增加较小。 

ENHANCEMENT OF HEAT TRANSFER IN TURBINE BLADE COOLING

An experimental study on fully-developed turbulent air flow in rectangular passages with two opposite rib-grooved roughened walls has been performed to determine the effects of the rib-grooved pitch-to-height ratios on friction factor and heat transfer coefficients. A general method for predicting average friction factor and average Stanton number in rectangular ducts with two smooth and two opposite rib-grooved walls is developed. Experimentalresults show that the performance of the heat transfer in the passages with rib-groovedroughened walls is better than that in the passages with rib roughened walls at the same s/h. This work may be useful to internal cooling design of the gas turbine blade.