叶片扩压器倒角对压气机性能影响的数值研究

研究了单级离心压气机中径向叶片扩压器倒角对其气动性能的影响.在倒角较小时,压气机单级性能改变不大,随着倒角的增大,堵点流量降低,效率和压比下降.在此基础上,开展了优化径向叶片扩压器倒角从而提升离心压气机气动性能的研究.结果表明:在径向扩压器吸力面采用无倒角或小倒角结构,防止流量堵塞,而在压力面采用沿弦向变半径倒角结构,抑制和消除压力面存在的分离,这种结构可明显提升所研究的离心压气机的气动性能.另外,进一步研究了在轮毂和机匣处分别采用如上倒角结构对气动性能的影响,发现轮毂处变倒角对性能优化起了主要作用. 

Numerical investigation of effect of radial vane diffuser fillet on performance of centrifugal compressor

The effect of the radial vane diffuser fillet on single-stage centrifugal compressor performance was studied.It was shown that when the radii of fillets were relatively small,the effect of the fillet can be negligible.Then further increasing the radius of the fillet,the mass flow at choke decreased and the performance of the compressor started to deteriorate.Upon these results,the investigation of optimizing the compressor aerodynamic performance by modifying the structure of the fillets was performed.Therefore,the fillet structure with no fillet or small fillets on suction side which can prevent blockage and radius-changing fillets on pressure side which can reduce or remove the separation zone on pressure surface was proposed.As a result,the performance of the compressor was improved obviously by using this structure.Besides,separated effects of fillets in casing and hub on single stage performance were discussed.It was revealed that the fillets near the hub played the major role in performance optimization.