通过商用计算流体力学软件Fluent 6.1求解Reynolds平均Navier-Stokes方程,研究了孔口倾斜角对合成射流激励器处于NACA0015翼型回流区时(20°攻角)控制分离剪切层的影响。结果表明:在孔口倾斜角为30°时,即吹气方向顺流向贴近壁面时,合成射流激励器控制翼型背风区分离剪切层的能力增加,合成射流对翼型的控制达到最佳效果;升力系数较垂直射流控制时增加5%,而阻力系数降低15%.通过对翼型气动力特性、脱落漩涡结构以及射流孔口附近流动结构的分析,揭示了小的孔口倾斜角下控制效果提升的内在机制。
Numerical simulation on effect of orifice inclined angle on separation flow control of the stalled NACA0015 airfoil was carried out by the Reynolds averaged Navier-Stocks equations solved with Fluent 6.1 at the high angle of attack(α=20°),i.e.orifice inclined angle relative to synthetic jet actuator locates in recirculation region of the airfoil.The calculated results demonstrate that the optimum orifice inclined angle is 30 degree for the synthetic jet controls the separated shear layer of the airfoil,which means the jet points to the stream-wise flow direction and is very close to the wall;at the inclined angle,lift coefficient of the airfoil increases by 5% compared with that with vertical jet flow control,meanwhile,drag coefficient of the airfoil decreases by 15%.The mechanism of the enhancement flow control effect at lower orifice inclined angle was also revealed by analyzing the vortex structure separated from the airfoil and the flow field near the actuator orifice.