跨声速轴流压气机转子弯掠控制机理

Controlling mechanisms of bowed and swept of rotor in transonic axial compressor

以1.5级跨声速轴流压气机为研究对象,采用三维数值模拟方法研究弯掠叶片技术对压气机不同工况的控制机理.结果表明:设计转速时前掠与反弯的组合弯掠优于前掠与正弯的组合弯掠,而部分转速时正好相反,这是因为不同弯掠方案对跨声速压气机不同工况的控制机理不同.设计转速时弯掠叶片改变叶顶激波强度和位置以及叶顶间隙泄漏涡强度,并改变叶片表面展向"C"型压力分布,三者共同作用从而提高设计转速时压气机的喘振裕度,但也造成设计转速效率下降;而部分转速时,压气机流场中的激波消失,弯掠叶片改变叶顶吸力面逆压力梯度和增强展向"C"型压力分布,两者共同作用使压气机的稳定性提高,但效率也会下降.

In a 1.5-stage transonic axial compressor, the controlling mechanism of bowed and swept blades was researched by 3-D numerical simulation when the compressor was working at different conditions. Results show that the combined scheme of sweepfor- ward and positive bow is better than the combined scheme of sweepback and negative bow at the design speed, but it＇s completely opposite at the part speed, because the controlling mechanisms of different bowed and swept schemes are different at the design speed and the part speed. The intensity and position of shock can be changed by the bowed and swept blades at the design speed, the same as the leakage vortex in the shroud gap and the span- wise C-shape pressure distribution~ so the surge margin of compressor could be improved by combined action of three changed factors, but followed with the decrease of efficiency. How- ever, the shock disappeared at the part speed, the reverse pressure gradient of the suction surface at the top of blade and the spanwise C-shape pressure distribution are changed, im- proving the aerodynamic stability of compressor and cutting down the efficiency.