叶尖小翼对跨声速压气机转子变工况性能的影响

为了进一步揭示叶尖小翼对跨声速压气机转子气动性能的影响机理,利用数值模拟方法研究了不同叶尖小翼安装方式对跨声速压气机转子气动性能的影响,并在分析跨声速压气机转子不同转速时的流动失稳机制的基础上探讨了叶尖小翼的扩稳机理.研究结果表明:最大宽度的压力面小翼在100%,80%及60%设计转速下分别使得跨声速压气机转子失速裕度增加8.1%,17.4%和7.1%.100%及80%设计转速时,转子叶尖区激波/叶尖泄漏涡干涉及泄漏涡破裂后产生的阻塞区是影响跨声速压气机转子内部流动失稳的关键因素.压力面小翼的扩稳机制在于降低了叶尖泄漏流强度,减弱了激波/叶尖泄漏涡干涉的强度,减小了叶尖泄漏涡破裂后产生的阻塞区.60%设计转速时,转子叶片吸力面气动过载导致的大面积的分离流动是诱发该跨声速压气机转子失稳的主要机制,此时压力面小翼的扩稳机制在于降低了转子叶尖来流的等效攻角,减弱了转子吸力面附面层三维分离的程度. 

Influence of blade tip winglet on the off-design performance of a transonic compressor rotor

In order to further reveal the influence mechanism of blade tip winglet on the aerodynamic performance of transonic compressor rotor, a numerical study of aerodynamic performance of transonic compressor rotor with different blade tip winglets was carried out. Base on the analysis of transonic compressor rotor flow instability at different speeds, the mechanism of stability enhancement by blade tip winglet was discussed. It is found that the stall margin of the transonic compressor rotor with the widest pressure-side winglet can be increased by 8.1%, 17.4% and 7.1% at 100%, 80% and 60% design speed conditions respectively. At 100% and 80% design speed conditions, the shock/tip leakage vortex interaction and the blockage zone caused by the tip leakage vortex breakdown are the key factors inducing the flow instability in a transonic compressor rotor. The mechanism of stability enhancement by pressure-side winglet contributes to the reduction of blockage zone caused by the tip leakage vortex breakdown, due to the strength reduction of tip leakage flow and shock/tip leakage vortex interaction. At 60% design speed condition, the large area boundary separation on the rotor blade suction surface plays an essential role to the flow instability inception. Compared with the rotor without tip winglet, the equivalent incidence of the rotor with pressure-side winglet is reduced and the degree of three-dimensional separation on the suction surface is weakened.