进口导叶预旋对扩压器内部非定常 流场影响的实验

在不同的进口导叶预旋角度和方向下,采用热线风速仪对扩压器内部非定常流场进行了测量,采用锁相采样-集平均技术对热膜测量的瞬时信号进行处理,研究了进口导叶预旋角度和方向对扩压器内部非定常流场的影响.结果表明,扩压器内部大部分湍流强度均有所增加;扩压器内的非定常性受导叶尾流及大尺度涡团的非定常影响而减小,且负预旋角度下非定常性的减小程度小于正预旋角度下非定常性的减小程度;扩压器内部的非定常流动的基本频率降低.

Experimental investigation of the influence of inlet guide vane prewhirl on the unsteady flowfield in the vaned diffuser

Experimental investigation of unsteady flow in the vaned diffuser of a centrifugal compressor stage was performed under different inlet guide vane (IGV) prewhirl angles and directions in this paper.Detailed instantaneous flow was measured at several different measuring positions using a hot-wire anemometer with the phase-locked ensemble-averaged technique,the influence of the IGV prewhirl angle and direction on the unsteady flowfield in the vaned diffuser was studied.In the existence of IGV prewhirl angle,the results show that the turbulence intensity increases at most of the position in the vaned diffuser;the unsteadiness in the vaned diffuser reduces due to the influence of the IGV wake and large size vortice,and the amplitude of the reduction under the negative IGV prewhirl is smaller than that under positive IGV prewhirl angle;the base frequency of the flow in the vaned diffuser decreases under the IGV prewhirl.