射流襟翼-低压涡轮叶栅主动流动控制数值研究

针对PAK-B低压涡轮叶型,基于耦合了Langtry-Menter转捩模型的Menter's SSTk-ω两方程模型,数值研究了不同流动状态下射流襟翼的流动控制机理.计算结果表明,射流襟翼能够有效控制PAK-B叶型失速流动状态下的损失,当射流流量百分数为2%,能量损失系数较无射流襟翼控制状态时下降40%;同时,气流转折角增大5%;影响并使主流进口质量流量减小10%,对于叶型未失速流动,控制不一定有效.结果还表明,射流襟翼能够推迟相邻叶型吸力面边界层转捩,从而延迟分离流动再附. 

Numerical study of active flow control using jet-flap for a low-pressure turbine cascade

Based on Menter's SST k-ω turbulence model coupled with Langtry-Menter transition model,the control mechanism of jet-flap,an active flow control method for PAK-Blow-pressure turbine blade profile,was numerically investigated under different flow conditions including different cascade inlet Reynolds numbers,free stream turbulence levels,and cascade outlet Mach numbers.The results show that the jet-flap effectively reduces flow loss when PAK-Bprofile is stalled.With jet flow mass fraction equal to 2%,relative to the baseline,the energy loss coefficient reduced by about 40%;the flow turning angle increased by about 5%;and the inlet primary flow mass reduced by about 10%.When the flow was not stalled,the control could be ineffective.The results also show that the jet-flap delays boundary layer transition on adjacent blade profile suction side, which in turn delays the boundary layer reattachment.