楔形涡流发生器影响高负荷叶栅性能的机理研究

Mechanism Investigation of Effects of Plow Vortex Generator on High-Load Compressor Cascade

关键词:  低马赫数  高负荷扩压叶栅  楔形涡流发生器  横向流动  角区分离

Key words:  Low Mach number  High-load compressor cascade  Plow vortex generator  Cross flow  Corner separation

摘要:

为探究楔形涡流发生器流动控制技术的作用机理，对一低来流马赫数高负荷扩压叶栅开展数值模拟研究。提出在叶片前缘安装涡流发生器的方案，并对比分析了采用涡流发生器前后叶栅性能及通道内二次流结构的改变。研究结果表明，楔形涡流发生器诱导的吸/压力面涡类似于叶片前缘的马蹄涡，卷吸附面层低能流体，提高其抗逆压梯度能力，进而削弱横向流动，抑制角区分离；涡流发生器的强漩涡结构改善了叶栅通道二次流，使得损失重新分布，叶栅-3°到7°攻角范围内的气动性能显著提升，设计点-1°攻角时平均总压损失系数下降8.04%，平均静压系数增大7.75%，5°攻角时平均总压损失系数下降15.87%，平均静压系数增大21.79%。

Abstract:

Numerical simulations were carried out to investigate the action mechanism of plow vortex generator (Plow VG) on flow control in a low-Mach number high-loaded compressor cascade. An approach installing vortex generators ahead of the blades leading edge was proposed， the change of the performance of the cascade and the structure of the secondary flow in the channel were compared and analyzed. According to the simulation results， vortex (suction / pressure surface vortex) induced by Plow VG is similar to the horseshoe vortex at the blade leading edge， owing to the vortex， low energy flow within boundary layer is rolled and the capability for resisting adverse pressure gradient is enhanced， weakening the cross flow and corner separation. Furthermore， strong vortex induced by Plow VG reduces the strength of secondary flow and redistributes the loss along the blade span， the aerodynamic performance of the cascade under -3° to 7° attack angle improved significantly， average total pressure loss coefficient decreased by 8.04% and average static pressure coefficient increases 7.75% at design point of -1° attack angle， average total pressure loss coefficient decreased by 15.87% and average static pressure coefficient increases 21.79% at the operating condition of 5° attack angle.