低雷诺数下尾迹与分离边界层的相互作用研究

 用有压力梯度平板模拟典型后加载负荷分布形式下低压涡轮吸力面边界层的发展，研究尾迹与分离边界层的相互作用，并对比了雷诺数变化的影响，还分析了在很低雷诺数下尾缘脱落旋涡和分离区的相互作用。结果表明，在相同出口马赫数下，随着雷诺数降低，壁面等熵马赫数发生变化，峰值马赫数有所降低。尾迹与分离区的相互作用，通过在分离区诱导卷起的旋涡，产生湍流以及Calmed区，抑制边界层分离。当雷诺数很低时，分离区与尾缘脱落旋涡的非定常现象需要在涡轮设计中给予关注。

Investigation of the Interaction Between Wake and Separated Boundary Layer at Low Reynolds Numbers

The suction boundary layer development of typical af t -loading low pressure turbine was modeled by flat plate with proper pressure gr adient.Interaction between the wake and the separated boundary layer was investi gated.The effect of Reynolds number was studied and the interaction of separated region with trailing edge vortex shedding at very low Reynolds number was analy zed.The results show that at the same exit Mach number, the isentropic Mach numb er of the wall changes and the peak Mach number decreases with decreasing Reynol ds number.The interaction of the wake and the separated region can suppress the boundary layer separation by turbulent and the calmed region produced by the bre akdown of rollup vortices induced by wake in the separated boundary layer.The un steadiness of the separated region and trailing edge vortex shedding should be p aid attention in turbine design process at very low Reynolds number.