来流特性对高速扩压叶栅端壁射流旋涡的影响

Effects of Inflow Characteristics on the Performance of the VGJ in a High-speed Compressor Cascade

在进口马赫数Ma=0.67的高速平面扩压叶栅上,开展了不同来流附面层厚度和湍流强度对端壁射流旋涡发生器控制效果的影响研究。结果表明,与来流湍流强度相比,进口附面层厚度对栅内流动的影响更大,随着其厚度的增加,栅内二次流动增强,损失增大;来流湍流强度对叶栅气动性能的影响减弱。射流旋涡在较小附面层厚度条件下减小栅内损失的效果随着湍流强度的增加而减弱,甚至会恶化其气动性能;而当附面厚度较大时,射流穿透能力减弱,湍流强度的增大将减小射流旋涡上洗区掺混损失并减缓其下洗侧与吸力面间端壁附面层的发展,叶栅气动性能的提高更加显著。当δ=15%H、T_u=10%时,射流旋涡使得栅内损失减小达8.4%。

Effects of the inflow characterized by different boundary layer thickness and turbulence intensity on the performance of the end-wall vortex generator jet （VGJ） were numerically investigated in a high-speed compressor cascade with an inlet Mach Number of Ma = 0. 67. The results indicate that the influence of the boundary layer thickness is greater than the turbulence intensity. With the increase of the thickness, the secondary flow and the loss are enhanced, whereas the influence of the turbulence intensity is decreased, The strengthened turbulence level degrades the performance of the VGJ even gains loss penalties for the thin boundary layer. In contrast, for the thickened boundary layer, the penetration of jet is weakened, increasing the benefit of the VGJ. Moreover, the increased inflow turbulence intensity could decrease the mixing in the up-washed side and delay the development of the end-wall boundary layer between the down-washed side and the suction side. As a result, the cascade performance is improved more obviously by using VGJ. For 8 = 15% H, T, = 10%, a loss reduction up to 8.4% is obtained.