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对不同雷诺数、不同来流湍流度条件下某典型高负荷低压涡轮叶片边界层流动进行了数值模拟,详细分析了雷诺数和湍流度对边界层分离与转捩的影响机制。结果表明:随着雷诺数的降低叶栅出口总压损失增大,一方面雷诺数减小吸力面边界层抗分离能力减弱,边界层分离引起损失增加,另一方面雷诺数减小吸力面层流边界层摩擦损失增大;随着湍流度的升高叶栅出口总压损失先减小后增大,这是因为低湍流度时流动分离损失占主要地位,湍流度增大分离减弱,叶栅总压损失减小;高湍流度时流动分离损失较小,边界层摩擦损失占主要地位,湍流度增大摩擦损失相应增加,叶栅总压损失增大。
The numerical simulation of the boundary layer flow at a typical high load and low pressure turbine blade under different Reynolds numbers and different turbulence flow conditions is carried out. The effects of Reynolds number and turbulence on the separation and transition of the boundary layer are analyzed in detail. The results show that as the Reynolds number decreases, the total pressure loss at the exit of the cascade increases. On the one hand, the Reynolds number reduces the anti-separation ability of the boundary layer on the suction side and the boundary layer separates. On the other hand, The friction loss of flow boundary layer increases; with the increase of turbulence, the total pressure loss at the exit of cascade first decreases and then increases, because the loss of flow separation plays a dominant role at low turbulence, the turbulence increases and the separation decreases, The loss of total pressure in the grid decreases. At high turbulence, the loss of flow separation is small, the boundary layer friction loss is the main factor, the turbulence increases with the increase of friction loss, and the total pressure loss of cascade increases.