透平叶顶气膜冷却效果数值研究

采用三维数值模拟方法,研究了GE E3发动机第一级透平动叶叶顶间隙内的气膜流动与换热特性,评估了气膜吹风比M分别为0.5、1.0和1.5时,对叶顶换热系数以及冷却效率的影响.计算结果表明:叶顶气膜冷却空气改变了叶顶泄漏流动特性,随着吹风比的增加,叶顶间隙内的泄漏流动区域不断缩小,从而导致叶顶间隙泄漏量不断减小;随着气膜冷却吹风比的增大,叶顶平均换热系数逐步降低;在M=1时,冷却效果最佳.

Numerical study of film cooling effectiveness on a flat-tip turbine blade

A numerical study is carried out to simulate the tip leakage flow and heat transfer on the blade tip of the first stage rotor of GE-E3 turbine.Three different blowing ratio(M=0.5,1.0,and 1.5) of cooling flow have been analyzed to evaluate the effect of blowing ratio on leakage flow and cooling effectiveness on the blade tip.Results indicate that as blowing ratio increases,the unblocked height above the film holes decreases.Film cooling reduces evidently the overall heat transfer on the tip,which shows the best performance at the blowing ratio M=1.0.