串列叶栅扩压器弦长比对离心压气机的性能影响研究

为研究串列叶栅前后排叶片的弦长比对离心压气机性能的影响规律,采用数值模拟的方法对某离心压气机扩压器进行串列改造,并在弦长比为0.7、1.0和2.0时对离心压气机级性能进行分析。研究结果表明:串列叶栅扩压器效率优于楔形扩压器,且可以明显扩宽压气机的工作裕度;串列叶栅弦长比在一定范围内数值越大,即前排叶片越短,压气机性能越佳。在串列叶栅扩压器后排叶片前缘附近添加合适弦长的小叶片可以在不降低离心压气机效率与工作裕度的同时提高总压比,同时拓宽其最大通流能力。

Numerical Study of the Tandem Cascade Chord Length Ratio on the Performance of Centrifugal Compressor

In order to study the influence of the chord length ratio of the tandem cascade on the performance of the centrifugal compressor, the numerical simulation method was used to carry out serial transformation of a cen-trifugal compressor diffuser, and the performance of the centrifugal compressor stage was analyzed when the chord length ratio was 0.7, 1.0 and 2.0. The results show that the efficiency of the tandem cascade diffuser is better than that of the wedge diffuser, and the operating margin of the compressor can be significantly widened; the chord length ratio of the tandem cascade is larger within a certain range, that is, the shorter the front row of blades, the better the performance of the compressor. Adding a small blade with a suitable chord length near the leading edge of the tandem cascade diffuser can increase the total pressure ratio without reducing the centrifugal compressor efficiency and working margin, while broadening its maximum flow capacity.