导叶预旋角对叶轮/扩压器相干的影响

A Study of the Effect of Inlet Guide Vane (IGV) Prewhirl Angles on Impeller/Diffuser Interaction

在不同进口导叶预旋角度下,采用非定常的方法对进口导叶/叶轮/扩压器3部件之间非定常相干进行了数值模拟,并与实验结果作比较。研究了进口导叶预旋角度对叶轮及扩压器内部流动及非定常性的影响,同时探讨了3部件之间动静相干的机理。结果表明,计算结果同实验结果吻合很好。在同等流量下,进口导叶的尾流和大尺寸涡团的非定常作用使得叶轮和扩压器上的非定常性减小,其变化弧度仅在原来的1/4左右。进口导叶为负预旋时,由进口导叶尾流所带来的非定常影响比进口导叶正预旋角度下小的多,但叶轮尾流及扩压器的势反冲效应所引起的非定常效应却较正预旋角度下有所增大。

Under different inlet-guide-vane(IGV) prewhirl angles and by using an unsteady approach,a numerical simulation was conducted of the unsteady interactions among the following three components:IGV,impeller and diffuser,moreover,a comparison with the test results was performed.Studied was the effect of IGV prewhirl angles on the flow and unsteadiness inside the impeller and diffuser.Meanwhile,the mechanism of interactions among the above-mentioned three moving and stationary components was also explored.The results show that the calculation results are in good agreement with the test ones.At a same flow rate,the wake flow of the IGV and the unsteady function of a large-sized vortex cluster will weaken the unsteadiness of the impeller and diffuser with the changing radian being only about 1/4 of the original magnitude.When the IGV assume a negative prewhirl angle,the unsteady influence brought about by the wake flow of the IGV is much smaller than that when the IGV take on a positive prewhirl angle.The unsteady effect arising from the wake flow of the impeller and potential-repercussion action of the diffuser,however,will be somewhat bigger than the case when the IGV have a positive prewhirl angle.