轴流压气机主流在封严篦齿上游容腔内流动结构的数值研究

Numerical Simulation Research of Flow Structure of Axial Compressor Mainstream in Upstream Cavity

为了解燃气轮机压气机静子上游容腔二次流结构以及提高效率,利用3维数值模拟方法对带有封严结构的压气机上游空腔内的流动结构和产生的气动损失进行分析,给定0.5%和1.0%的间隙叶高比,并研究主流在上游容腔结构内产生的二次流与泄漏流的相互作用。静子通道内的二次流除了通过封严篦齿的泄漏流外,主流会在上游容腔内产生与泄漏流类似的与主流流向差异较大的二次流。分析结果表明:间隙叶高比为0.5%与间隙叶高比为1.0%相比,泄漏量减少53%的同时损失系数只降低1.784%,主流在上游容腔内会产生较多的二次流,而间隙叶高比为1.0%的情况下泄漏量增加,主流在上游容腔结构内产生的二次流效应减弱。

Three-dimensional numerical simulations have been performed to investigate the flow structure of the upstream cavity and the aerodynamic loss in a compressor cascade with labyrinth seal.On the basis of this analysis,the interaction of the secondary flow generated by upstream cavity and the leakage flow was studied.In addition to the classical hub secondary flow that caught by labyrinth seal,another secondary flow was found which is similar to leakage flow and generated by the mainstream in the upstream cavity.Detailed analyses of the interaction of the upstream cavity secondary flow and the leakage flow reveals:when the percent of seal-clearance/blade span ratio decreases from 1.0%to 0.5%,the mass of leakage flow decreases by 53%and the aerodynamic loss only decreases by 1.784%.With 0.5%seal clearance ratio,the upstream cavity creates more secondary flow.With increasing seal clearance ratio,the secondary flow effect generated by upstream cavity is weaken.