中文摘要：

本文对一高速离心风机中扩压器与叶轮匹配时的气动性能进行了试验研究，主要研究了扩压器前缘不同倾角对其性能的影响。结果表明，扩压器倾角变化对性能有明显的影响；当负倾角在一定范围内时，扩压器的压升在小流量下略高于原始扩压器，而大流量下明显高于原始扩压器。另外，正倾角扩压器的性能曲线具有相交于一固定点的特征．因此，具有合适前缘倾角的扩压器可以改善风机性能。

英文摘要：

An experimental study of the effect of an improved vaned diffuser on a high speed centrifugal fan has been carried out, the improved diffuser vane has an inclined leading edge along its height. Seven inclined leading edge vaned diffusers （ILEVD） with inclined angles of 45°, 60°, 75°, -30°, -38°, -45° and -60° were tested. The aim of the experimental study is to find a good matching between the centrifugal impeller and the vaned diffuser to improve the fan performance. The result shows that, when the ILEVD angle value is located in an adapted range, in small flow rate condition the fan pressure rise is slightly larger than that having an original 90° diffuser, while in the large flow condition has an significant increases. The performance of the ILEVD having negative incline angle is better than the ILEVD having positive incline angle, especially in the small flow rate condition. Among all the tested diffusers, the ILVED having the incline angle of -45° has the best aerodynamic performance. In addition, the ILEVD broadens the fan operating range.