叶轮是决定离心压气机气动性能的关键因素之一，在保持叶轮设计参数不变的条件下，调整叶根倒角的分布，对比分析叶根倒角对压气机性能的影响。利用Numeca软件对跨声速离心压气机进行全三维稳态流动数值模拟方案分为等半径倒角与变半径倒角两种。结果表明：主叶片后半弦长的倒角是决定压气机气动性能的关键性因素，尾缘倒角比前缘更敏感；根部倒角使得叶片吸力面角涡的形成提前、流动过程中角涡的扩散加快，致使叶片轮毂面附近的附面层增厚、流动更易分离，导致叶轮流通面积及流程气流转折角减小、受力面静压差降低，从而降低做功能力、恶化压比特性；在设计工况，绝热效率下降可达0.64%，总压比下降可达1.23%，且降幅随倒角增大而增大。因此，在保证可靠性的前提下，应尽量减小叶轮根部尤其是主叶片后半弦长的倒角半径值。

The impeller is one of the key factors that determine the aerodynamic performance of a centrifugal compressor.The influence of blade root fillets on compressor performance was compared and analyzed by adjusting the distribution of blade root fillets and by keeping the impeller design parameters unchanged.Full 3D steadystate flow numerical simulation of transonic centrifugal compressor was carried out by Numeca software.The simulation scheme consists of equal radius fillets and variable radius fillets.The results show that the fillet size of the back half chord length of the main blade is the key factor to determine the aerodynamic performance of the compressor,the fillet size of trailing edge is more sensitive than that of leading edge.The root fillet causes the formation of corner vortexes on the suction surface of the blade to come in advance and the diffusion of corner vortexes to speed up in the flow process,as a result,the boundary layer near the hub surface of the blade thickens and the flow is easier to separate,leading to the decreases of the flow area of impeller,the process flow turning angle and the static pressure difference of the bearing surface,thus reducing the power capacity and worsening the pressure ratio characteristics.Under the design condition,the decrease of adiabatic efficiency can reach up to 0.64% and the decrease of total pressure ratio can reach up to 1.23%,moreover,the decreasing amplitude increases with the increase of fillets.Therefore,on the premise of ensuring the reliability,the fillet radius of the impeller root,especially that of the back half chord length of the main blade,should be reduced as far as possible.

TH452

国家自然科学基金(11202043)；辽宁省自然科学基金(201602112)