几何参数对离心叶轮强度和气动性能影响的研究

使用有限元计算软件和内部流场计算软件对所设计的几个具有不同几何尺寸的离心压气机叶轮的强度和气动性能进行了计算。结果表明反弯叶片可降低叶轮出口处叶片根部附近的应力,但会造成叶片根部前缘区域应力集中,且反弯叶轮的气动性能和原型叶轮差别不大。前倾叶片能在很大程度上降低叶轮出口处叶片根部应力,前倾角越大出口叶根处应力减小越多;随前倾角增大,叶轮气动性能恶化程度加剧;叶轮的背盘形状对叶轮的应力影响较大,尤其是出口处的背盘厚度对出口处叶片根部区域的应力起主因作用。研究得出叶片几何及背盘形状因素对叶轮应力分布的影响规律,另外还得到了叶片几何形状对气动性能的影响规律,这些工作为叶轮的多学科优化设计提供良好的基础。

Investigation of Geometrical Parameters Influence to the Stress and Aerodynamic Performance of Centrifugal Impeller

For the purpose of multidisciplinary optimized to turbomachinery blade,it’s necessary to study the influence of geometrical parameters like positive,negative curve and lean angle to the stress and aerodynamic performance of centrifugal impellers.Several different centrifugal impellers were designed and CFD calculation was performed to them.Finite element stress analysis was also performed to these centrifugal impellers over different blade profile and backface shape.The result shows that the negative curved blade could lower the maximum stress whereas brings stress concentrate at the blade hub leading edge zone,and doesn’t bring notable damage to impeller’s aerodynamic performance.The forward lean blade could minish the impeller stress with compromise to the impeller aerodynamic performance.Pressure ratio and efficiency are declined with the increases of lean angle.The FEA results also indicate that backface shape especially the thickness of the outlet backface of impeller has great effect on the impeller outlet zone stress.All these conclusions can be the foundation of multidisciplinary optimization of impeller.