叶尖间隙对民用大涵道比跨音速压气机性能的影响

以某民用大涵道比涡扇发动机高压压气机进口级为研究对象,数值研究了叶尖间隙对进口级高负荷跨音速转子叶片气动性能的影响。数值结果表明：随着叶尖间隙值增加,流量-压比与流量-效率特性线向左下方偏移,最大流量、最高压比、峰值效率逐渐降低；存在间隙对该跨音转子性能影响不敏感的范围值0mm~0.3mm；当间隙值大于0.3mm,最大流量的减小与间隙的增大呈现出近似的线性关系,最高压比和峰值效率急剧下降；间隙从0.3mm增加至1.0mm,转子总压损失增大了41%；叶尖泄漏流与通道激波相互作用,泄漏流穿过激波后在叶片压力面侧形成较大的高熵值损失区域,当叶尖间隙增大到1.0mm,泄漏流平行额线方向流动,使得贴近前缘的激波变得不明显；叶尖泄漏流对叶片通道主流的影响集中在叶高80%以上区域。

Influence of tip clearance on civil high-bypass-ratio transonic compressor aerodynamic performance

Numerical study of tip clearance on the aerodynamic performance of high loading transonic compressor was conducted, based on inlet stage of high pressure compressor of one civil high-bypass-ratio turbofan engine. The results show that the performance curves of mass flow versus pressure ratio and adiabatic efficiency go to left and down direction. The value of maximum mass flow, maximum pressure ratio and peak efficiency decreases gradually. There is a range of tip clearance from 0 millimeter to 0.3 millimeter between which the influence of tip clearance on performance character is trivial. When tip clearance is larger than 0.3 millimeter, the reduction of maximum mass flow shows the liner relation with the increasing of tip clearance. Besides, maximum pressure ratio and peak efficiency decline rapidly. The total pressure loss of the rotor increases 41 percent at 1.0 millimeter, compared to tip clearance of 0.3 millimeter. Tip leakage flow penetrates the shock wave, reacts with it and forms high entropy flow near the pressure side of the passage. When tip clearance is 1.0 millimeter, tip leakage flow leaks traverse from leading edge across the passage. The shock wave appears unconspicuous. Tip leakage flow affects main flow above of 80 percent span of blade.