低速离心压气机非稳态流和机匣处理的数值分析

Numerical analysis for the unsteady flow and casing treatment in a low speed centrifugal compressor

机匣处理能够改善压气机稳定裕度,扩大其稳定工作范围。为了验证并分析其扩稳机理,对带沿气流流向槽的低速离心压气机内部进行了全三维数值模拟,将数值计算结果与实验结果进行了比较,并详细对比分析了实壁机匣和机匣处理后离心压气机转子顶部区域流场结构,以及阐述了机匣处理对叶顶间隙泄漏涡和二次流等非稳态三维紊流流动的影响。

The casing treatment has the potential to extend the operating range of compressor. A time accurate 3-dimentional numerical simulation was performed for the casing treatment in a low speed centrifugal compressor in order to check and analyze the working mechanism by which easing treatment improves stall margin. The results between the numerical calculations and the experiments are compared. The different tip flow topologies between the eases with easing treatment and with untreated smooth wall have been exposed by detailed analyses of the flow visualization at the tip of the blades. The effect of easing treatment on the tip leakage vortex and secondary flow is discussed.