摘要
针对基于Pack B叶型的低稠度大负荷涡轮叶栅,采用定常数值模拟方法研究了两种流动控制技术——射流襟翼与Gurney襟翼(圆形、方形和圆弧凸起形)对低雷诺数下涡轮叶栅流动分离损失的控制.结果表明,射流襟翼和Gurney襟翼均可使主流流动偏转,增大叶型的气流转折角,影响叶型载荷系数;由于主流流动的偏转,影响并加速相邻叶型吸力面边界层流动,使得主流对于相邻叶片吸力面后缘处的逆压梯度降低,推迟了边界层层流向湍流的转捩,延长加速区,推迟了边界层分离,使得再附点位置提前,减小由逆压梯度引起的叶型吸力面分离区范围;H=1%的圆形Gurney襟翼和H=0.8%的方形Gurney襟翼均能在保证提高同等水平Zweifel载荷系数值的同时,将能量损失系数降到与设计栅距时相当的水平.
Detailed numerical simulations were performed to study the effect of the flow control,jet-flap and Gurney-flap（round,square and smooth-convex） on the loss of high-loading turbine cascade flow separation with low Reynolds number,whose pitch was enlarged by 12.5% based on Pack B airfoil.The results show that the flow direction of the turbine cascade mainstream can be changed by both jet-flap and Gurney-flap,and then the flow angle is increased,all of which contribute to Zweifel loading coefficient.The deflection of the cascade mainstream can decrease the adverse pressure gradient along the rear suction side of the adjacent blade,affect and accelerate the flow at suction side of the adjacent blade,and then extend the accelerating section,consequently delay the boundary layer separation and bring forward the reattachment point,thus shortening the separation zone induced by the adverse pressure gradient.With H=1% round Gurney-flap and H=0.8% square Gurney-flap,the cascade Zweifel loading coefficient is improved by 12.5% and 13.3%,while the cascade energy loss coefficient is reduced to the equivalent level as the design condition.
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2010年第11期2528-2538,共11页
Journal of Aerospace Power
基金
国防预研课题
