中文摘要：

使用X热线热膜技术,在设计流量下研究了3个不同进口导叶（inlet guide vanes,IGV）预旋角对叶片扩压器进口流场的影响。分析表明：集平均速度在不同预旋角下变化明显,且其在不同叶高处的变化规律不同。10%叶高处,3个预旋角下集平均绝对气流角均为负冲角;50%叶高处,-20°预旋角和0°预旋角下气流角为负冲角,但20°预旋角下在主叶片尾迹区附近出现正冲角;90%叶高处,集平均绝对气流角几乎均为负值。3个预旋角下,时间平均气流角在10%、50%和90%叶高处分别改变1.4°、2.2°和1.3°,表明预旋角对扩压器进口气流角影响较大,且对中间叶高处气流角的影响明显大于轮盘和轮盖侧;不同叶高处时间平均脉动角变化不超过0.6°,表明预旋角对脉动角影响相对较小。气流角沿叶高变化较大,推荐扩压器叶片进口缘沿轴向适当扭曲。

英文摘要：

The effects of inlet guide vanes （IGV） prewhirl angles on the diffuser inlet flow filed in a centrifugal compressor were experimentally investigated under design condition by using the X-type hot-film anemometry. The results show that the ensemble-average velocity varies significantly at different IGV prewhirl angles, and the variation patterns are different in spanwise direction. At 10% spanwise position, the ensemble-average attack angle is negative under all three IGV prewhirl angles; at 50% spanwise position, this angle is negative under ？20 degree and 0 degree prewhirl angles, while it is positive close to the main blade wake region under 20 degree prewhirl angle; at 90% spanwise position, the ensemble-average absolute flow angle is almost negative. Under three IGV prewhirl angles, the variations of time-average absolute flow angle are respectively 1.4, 2.2 and 1.3 degree at 10%, 50% and 90% spanwise positions, which indicates that the IGV prewhirl angle has great impact on the diffuser inlet flow angle, and this impact is more remarkable at mid-span than that close to hub and shroud; however, the variations of time-averaged random unsteady fluctuation flow angle at three spanwise positions are all less than 0.6 degree, which are relatively small. Due to the large variation of the absolute outflow angle, the twisting of the diffuser vane leading edge along the axial direction was recommended.