基于大涡模拟的低压涡轮平面叶栅非定常流动机理研究  

Large Eddy Simulation of Unsteady Flow Mechanism in Low Pressure Turbine Cascade

作　　者：王云飞 崔可 宋彦萍[3] 陈浮[3] WANG Yunfei;CUI Ke;SONG Yanping;CHEN Fu(School of Transportation and Vehicle Engineering,Shandong University of Technology,Zibo 255000,Shandong Province,China;CRRC Zhuzhou Electric Co.,Ltd.,Zhuzhou 412001,Hunan Province,China;School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150001,Heilongjiang Province,China)

机构地区：[1]山东理工大学交通与车辆工程学院,山东省淄博市255000 [2]中车株洲电机有限公司,湖南省株洲市412001 [3]哈尔滨工业大学能源科学与工程学院,黑龙江哈尔滨市150001

出　　处：《中国电机工程学报》2020年第24期8082-8089,共8页Proceedings of the CSEE

摘　　要：为深入认识高负荷低压涡轮叶栅表面边界层的非定常演化过程,采用三维可压缩大涡模拟方法,对低压涡轮叶栅内部流动机理进行研究。基于等熵膨胀过程定义的叶栅出口雷诺数为0.6×10^(5),马赫数为0.404,计算获得的吸力面时均切应力和叶栅出口总压损失系数与实验及直接数值模拟结果吻合度较高。研究结果表明:低雷诺数条件下,低压涡轮叶栅吸力面边界层内流体的转捩过程接近于自然转捩;瞬态流场中,吸力面边界层分离后没有始终处于分离状态,而是出现了间歇性再附现象,多个小尺寸分离泡同时存在于吸力面侧;边界层分离区仅为低能流体的聚集区,并非气动损失的来源区。In order to deeply understand the spatiotemporal evolution of unsteady flow in a high-load low pressure turbine cascade, a large eddy simulation program of compressible Navier-Stokes equations based on dynamic Smagorinsky model was developed. The Mach number was 0.4 and Reynolds number at the outlet was 0.6×10^(5)(based on isentropic expansion process). The distribution of timeaveraged wall-static pressure coefficient and total pressure loss coefficient agreed well with experiment and direct numerical simulation results. The numerical results show that the transition process of the fluid in suction side boundary layer is close to natural transition at low Reynolds number. In the transient flow field, the boundary layer near the rear part of the suction side subjected to intermittent separation and reattachment. More than one separation bubble existed on the cascade surface. The separation zone was just the accumulation area of low-energy fluid rather than the region of aerodynamic loss source.

关 键 词：大涡模拟 低压涡轮 叶栅 边界层分离 自然转捩 气动损失 

分 类 号：TK472[动力工程及工程热物理—动力机械及工程]