高速径流式涡轮叶顶间隙流动研究  

Study on Tip Clearance Flows in a High-Speed Radial Turbine

作　　者：史亚东[1] 王强[1] 张翼[1] 张继忠[2] Shi Yadong Wang Qiang Zhang Yi Zhang Jizhong(School of Mechanical and Power Engineering, North University of China, Taiyuan 030051, China China North Engine Research Institute （Tianjin）, Tianjin 300400, China)

机构地区：[1]中北大学机械与动力工程学院,山西太原030051 [2]中国北方发动机研究所(天津),天津300400

出　　处：《内燃机学报》2016年第5期473-479,共7页Transactions of Csice

基　　金：柴油机高增压技术国防科技重点实验室基金资助项目(9140C330403130C33115);中国博士后基金资助项目(2011M500545)

摘　　要：针对高速径流式涡轮,利用NUMECA软件建立计算模型进行雷诺平均Navier-Stokes方程(RANS)计算,采用Spalart-Allmaras湍流模型,分析了不同叶顶间隙对叶轮气动性能、间隙区域温度场、泄漏涡流及涡轮级性能的影响.结果表明:减小叶顶间隙会出现新的流动特性—逆流现象,表现为叶顶间隙通道内流体流动方向与压力梯度方向相反,即由叶片吸力面侧指向压力面侧,这一新流动特性极大地改变了间隙区域温度场;大间隙造成的气动损失不可忽视,减小叶顶间隙可抑制泄漏涡流强度,提高涡轮效率,从而改善涡轮性能.Abstract： Using the NUMECA software, a high-speed radial turbine model was built and RANS calculations were conducted and the Spalart-Allmaras turbulence model was used to analyze the effects of different tip clearances on the impeller aerodynamic performance, temperature field in tip gap region, leakage vortex and performance of turbine stage. Results show that a new flow, reversed flow, appears when reducing the clearance, in the direction from blade suction side to pressure side of flow in tip gap region channel opposite to the one of pressure gradient. The novel flow topology largely alters the temperature field in tip gap region. Moreover, large tip clearance results in non-negligible aerodynamic loss. Reducing clearance can suppress the intensity of leakage vortex and improve turbine efficiency and performance. Keywords： radial turbine; tip clearance; leakage flow; reversed flow; turbine performance

关 键 词：径流式涡轮 叶顶间隙 泄漏流动 逆流 涡轮性能 

分 类 号：TK401[动力工程及工程热物理—动力机械及工程]