叶片变形对涡轮增压器用离心压气机气动性能的影响及机理

The Effect and Mechanism of Blade Deformation on Aerodynamic Performance of Centrifugal Compressor Used in Turbocharger

为了研究叶片变形对涡轮增压器用离心压气机气动性能的影响,采用流固耦合方法计算设计转速下近喘振点、最高效率点和近阻塞点三个工况处的压气机性能。研究结果表明:叶片变形主要受离心载荷的影响,其影响占比为92.11%~97.22%,叶片最大变形发生在主叶片前缘叶顶处,叶轮最大应力发生在叶轮轴孔底部;从近阻塞点到近喘振点,气动载荷引起的叶片变形不断增大,约占叶片总变形的2.78%~7.89%;变形后压气机效率和压比分别提高0.3%和0.06%,阻塞流量有所减小;发现气动载荷导致的变形方向与离心载荷导致的变形方向相反,叶片变形主要通过改变叶顶间隙来影响离心压气机的气动性能。研究成果为离心压缩机气动及预变形设计优化提供了参考依据。

In order to study the effect of blade deformation on the aerodynamic performance of a centrifugal compressor used for turbocharger,the fluid-structure coupling method was used to calculate the compressor performance at three operating conditions,i.e.,near-surge point,peak efficiency point and near-choke point at the design rotational speed.The results show that the blade deformation is mainly affected by centrifugal load,which accounts for 92.11%~97.22%,the maximum deformation of the blade occurs at the tip of leading edge of the main blade,and the maximum stress of the impeller occurs at the bottom of the impeller shaft hole;from the near-choke point to near-surge point,the blade deformation caused by aerodynamic load increases continuously,accounting for 2.78%~8.33%of the total blade deformation;after deformation,the compressor efficiency and pressure ratio increase by 0.3%and 0.15%respectively,and the choking mass flow decreases;it is found that the deformation direction caused by aerodynamic load is opposite to that caused by centrifugal load,and the blade deformation mainly affects the aerodynamic performance of centrifugal compressor by changing the tip clearance.The research results provide reference for aerodynamic and pre-deformation design optimization of centrifugal compressor.