离心压气机自循环预旋喷气机匣处理的设计和验证

采用一种预旋喷气机匣处理提高离心压气机特定转速范围内的稳定裕度.通过引气加大离心叶轮进口基元级流量降低通道堵塞,并借助回流预旋喷气改变前缘攻角抑制叶背分离是该机匣处理扩稳的主要机理.基于这样的认识,对机匣处理做了几何参数设计研究,发现轴向搭接位置、搭接长度和开槽角度是影响机匣处理性能的3个主要参数.通过几何参数的合理选取,在尽量提高80%设计转速稳定裕度的同时兼顾100%设计转速的效率.压气机部件性能试验验证了该设计方法的有效性,并观测到在低转速时,机匣处理可以同时提高稳定裕度和效率. 

Investigation of self-recirculating casing treatment with preswirl blowing for centrifugal compressor

Numerical and experimental investigations have been conducted on a self-recirculating casing treatment for a centrifugal compressor.Stall margin improved due to redirecting the low-momentum fluid to increase the mass flow in the impeller passage and decreasing the positive attack angle in the tip region with preswirl blowing.Based on the working mechanism,parametric studies were conducted to design the casing treatment geometry.It was found that the angle of the grooves,the position and the length of overlap were three key parameters for the"best casing configuration"in terms of larger stall margin improvement and smaller lowering of efficiency according to the given range of rotating speeds.The effectiveness of this casing treatment was verified by the single stage centrifugal compressor experiments,and it was observed that the stall margin and efficiency can be improved simultaneously at lower rotating speed.