轴流压气机折线缝式机匣处理扩稳机理

1引言风扇/压气机的气动失稳不但会对其气动性能造成恶劣影响,而且还有可能对发动机结构造成毁灭性的破坏。因此,如何延迟风扇/压气机气动失稳的发生,拓展稳定工作范围,一直是提高其性能的关键技术之一。机匣处理是一种扩大压气机稳定工作范围的有效措施,然而,大多数机匣处理在

Mechanism of axial-flow compressor stall margin improvement associated with bend skewed slots casing treatment

The bend skewed slot casing treatment has the potential, to significantly extend the stall margin of the compressor with minimal or no loss in efficiency. In order to uncover the working mechanism by which bend skewed slots casing treatments improve stall margin and also the flow mechanisms the bend skewed slots casing treatments differ from axial skewed slots casing treatment, a time accurate 3-dimentional numerical simulation was performed for the subsonic axial-flow compressor rotor both with bend skewed slot casing treatment and axial skewed slot casing treatment. The numerical results agreed well with experimental data for the global performance. Detailed analyses of the flow visualization at the tip have exposed the different tip flow topologies between the cases with casing treatment and with untreated smooth wall. It was found that the repositioning of the tip vortex trajectory further towards the trailing edge of the blade passage and delaying the movement of incoming/tip clearance flow interface to the leading edge plane are the exact mechanism of stall suppression imposed by bend skewed slot casing treatment.