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为了揭示叶顶喷气对高负荷压气机气动性能和稳定裕度的非定常影响机理,对一跨声速轴流压气机进行六通道三维非定常数值模拟,定量分析了两种喷嘴作用下压气机内部流场的变化。研究表明叶顶喷气提升了压气机的总压比和稳定裕度,对效率的影响不大,喷气量决定了对压气机气动性能的影响程度。喷气引起叶顶进出口流量的非同步周期性变化,当喷气流沿通道到达转子尾缘后完成对叶顶的降载作用,叶顶负荷呈周期性变化。喷嘴喉部高度不变时,27.3%和54.6%的周向覆盖比例分别获得3.3%和3.6%的裕度改进,分析可知喷气的扩稳效果取决于喷气对叶顶堵塞的抑制在通道出口产生的影响。喷气流在通道中的流动延迟使得喷气对通道出口堵塞抑制的时间大于对通道进口堵塞的抑制时间,因而较小宽度的喷嘴可以保证对叶顶堵塞的有效抑制,增加喷嘴的宽度对稳定裕度的影响不大。
In order to reveal the unsteady influence mechanism of tip-jet on aerodynamic performance and stability margin of high-load compressor, a six-channel three-dimensional unsteady numerical simulation of a transonic axial-flow compressor was carried out. The effects of two kinds of nozzles on the internal pressure of compressor Flow field changes. The research shows that the tip jet enhances the total pressure ratio and the stability margin of the compressor, and has little effect on the efficiency. The amount of jet determines the effect on the aerodynamic performance of the compressor. The unsteady periodic change of the flow at the tip of the jet caused by the jet air jet, when the jet flow reaches the rotor trailing edge of the rotor along the channel, the load on the blade tip is reduced and the load on the blade tip changes periodically. When the nozzle throat height is constant, the coverage ratio of 27.3% and 54.6% of the circumferential coverage is improved by 3.3% and 3.6%, respectively. It can be seen from the analysis that the effect of jet expansion depends on the inhibition of jet plugging at the outlet of the channel Impact. The delay of the jet flow in the passage causes the jet to block the exit of the passage more than the suppression of the entrance to the passage so that the smaller width of the nozzle can effectively prevent the blockage of the tip and increase the width of the nozzle against the stability margin Little effect.