尾缘造型及冷气喷射对跨声速涡轮叶栅损失的影响

Effects of Trailing Edge Profile and Coolant Ejection on the Loss in a Transonic Turbine Cascade

通过对不同尾缘造型、不同尾缘冷气喷射量下某跨声速涡轮叶栅的数值模拟,初步得出了尾缘劈缝冷却对尾缘损失以及叶栅能量损失影响的规律。其主要表现为:从减小叶栅能量损失角度来讲,尾缘冷气喷射流量存在最佳值,且随劈缝长度增加,此最佳冷气喷射流量越小;从减小尾缘激波强度角度来讲,较大的冷气流量以及较长的尾缘劈缝有利于减小激波损失,但会消耗过多冷气并增加掺混损失,导致总损失增加。

Numerical simulations had been performed in transonic cascades with different cut-back length and ejecting rate of trailing edge coolant in order to find out how the length of trailing edge cut-back and the mass flow rate of coolant affect the trailing edge loss and energy loss of cascade. The results showed that the coolant flow rate has a best value from the point of minimizing the energy loss. This best coolant flow rate decreases with the increasing length of cut-back. A higher coolant flow rate or a longer cut-back are beneficial for minimizing the intensity of trailing edge shockwave, which instead consumes too much coolant and increases mixing loss.