基于HLLC格式的径向叶轮叶顶间隙流场分析  

Analysis of Tip Clearance Flow in Radial Impeller Based on the HLLC Scheme

作　　者：肖军[1] 赵远扬[1] 王乐[1] 

机构地区：[1]合肥通用机械研究院压缩机技术国家重点实验室,合肥230031

出　　处：《机械工程学报》2013年第18期167-176,共10页Journal of Mechanical Engineering

基　　金：国家重点基础研究发展计划资助项目(973计划;2012CB026001)

摘　　要：推导出相对旋转坐标系下的HLLC(Harten,Lax,van Leer,contact)通量算式,自行开发基于多块结构化网格的有限体积程序,实现对叶轮机械流场的数值求解。分别对闭式后弯叶轮、半开式径向叶轮展开流场数值模拟,通过不同叶高处表面压力等数据的比较表明,模拟结果和商业软件吻合较好,算法的正确性得到验证。以半开式径向叶轮为研究对象,展开叶顶间隙流动的特性分析。计算结果表明,叶顶间隙的总泄漏量随叶轮扩散因子的增加而近似线性地增大,但泄漏量的绝对数值及泄漏损失随扩散因子的增加而减小。间隙泄漏受叶顶载荷驱动,泄漏机制在一定转速范围内具有相似性。近堵工况泄漏涡产生的位置偏后,但衰减更快。By deducting the HLLC（Harten, Lax, van Leer, Contact） fluxes of convective terms in the rotating coordinate system, a finite volume analysis code based on multi-block structured grids is developed independently, which aims at realizing the numerical solving of internal flow fields of turbo machineries. The flow simulations of a shrouded backswept impeller and an unshrouded radial impeller are carried out respectively. The calculated data such as surface pressure at various blade heights show favorable agreement with the data from commercial software, which verifies the accuracy of the algorithm. Then the characteristic analysis of tip clearance flow for the radial impeller is carried out. The results obtained indicate that, although the total leakage mass flow rises almost linearly as the impeller diffusion factor increases, the absolute value of leakage mass flow and the leakage loss decrease as the diffusion factor increases. Clearance leakage is driven by the loading near blade tip, and the leakage mechanism shows some similarity within a certain range of rotational speed. Under near choke operation point the generation spot of leakage vortex shifts more downstream, but attenuates faster.

关 键 词：径向叶轮 间隙流动 HLLC通量 数值模拟 扩散因子 

分 类 号：V231[航空宇航科学与技术—航空宇航推进理论与工程]