转速匹配效应影响下周向槽机匣处理对转压气机性能的影响

Effect of circumferential groove casing treatment on performance of counter-rotating compressor under influence of speed matching effect

采用数值模拟方法,通过分别在对转压气机(counter-rotating compressor,CRC)前后两排转子上进行周向槽机匣处理,研究了其在不同转速匹配方案下的扩稳效果以及对转压气机最先失速级的变化规律。结果表明:当前排转子R1转速高于后排转子R2时,其最先失速级为R1,当R2转速等于或高于R1时,其最先失速级为R2。在对转压气机的最先失速级进行机匣处理可以有效改善所处理转子的叶尖附近流场,包括来流相对气流角的减小、叶尖泄漏流反向轴向动量的减小、叶尖泄漏流与主流交界面位置的后移及叶尖堵塞程度的减弱等,进而提升了其失速裕度。机匣处理一般仅能对所处理转子的流场产生较大影响,但在特殊情况下也会使非处理转子的流场发生明显改变。

Numerical simulation method was used to study the stability enhancement effect under different rotational speed matching schemes and the change of first stall stage of counter-rotating compressor(CRC)by performing circumferential groove casing treatment on front and rear rotors of the counter-rotating compressor respectively.The results showed that when the rotational speed of front rotor R1 was higher than that of rear rotor R2,its first stall stage was R1,and when the rotational speed of R2 was equal to or higher than R1,its first stall stage was R2.Casing treatment on first stall stage of the counter-rotating compressor can effectively improve the flow field near blade tip of the treated rotor,including reduction of relative flow angle of inflow,decrease of reverse axial momentum of tip leakage flow,backward movement of interface between tip leakage flow and main flow,and reduction of blade tip blockage,etc.,and then improve its stall margin.Generally,the casing treatment can only have a great influence on the flow field of treated rotor,but in special cases,the flow field of non-treated rotor can also be significantly changed.