离心压气机凹槽导流片式机匣处理失速控制研究

A Study of the Stall Control Involved in the Casing Treatment of a Centrifugal Compressor with Recessed Guide Vanes

针对一种新型的可显著改善原有压气机稳定裕度的机匣处理结构,进行了时间精确的三维数值模拟,详细对比分析了带实壁机匣结构和凹槽导流片式机匣处理结构的离心压气机转子叶片顶部区域流场,以及叶片通道内子午速度沿径向的分布情况,揭示了凹槽导流片式处理机匣结构的扩稳机理。并通过分析不同参数的凹槽导流片式机匣处理的计算结果,表明:轴向叠合量的增大,对于压气机裕度的改善有利,而不利于压气机的效率提升;处理槽深度的减少,会使压气机稳定裕度有所改善,但峰值点总压比与失速点总压比都有所降低。

The authors have conducted an accurate time-variant three-dimensional numerical simulation with respect to a new type casing treatment structure that can remarkably improve the stability margin of the original compressor.A detailed comparison and analysis was performed of the flow fields in the blade tip region of a centrifugal compressor with a solid-wall casing structure and recessed guide vane type casing treatment structure.The meridian speed distribution inside the blade passages in the radial direction is also analyzed,thus revealing the diffusion stabilization mechanism of the casing treatment structure with recessed guide vanes.An analysis of the calculation results of casing treatment with recessed guide vanes of different parameters shows that the increase in the axial overlapping amount is favorable for improving the stability margin of the compressor but unfavorable for enhancing its efficiency.The decrease of the groove depth will somehow improve the stability margin of the compressor.The total pressure ratios at both the peak and the stall point,however,will be somewhat reduced.