为了研究合成射流激励器处于NACA0015翼型回流区时对其分离流动的控制,采用商用计算流体力学软件Fluent 6.1求解Reynolds平均Navier—Stokes方程,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,揭示了合成射流处于分离区时对边界层控制的机理.结果表明:当合成射流孔口处于回流区时仍可有效推迟翼面边界层分离点,缩小回流区范围,从而有效提高翼型的升力.当射流方向垂直于壁面,无量纲频率以及吹气速度比都等于1时,翼型平均升力系数提高40%左右.
Numerical simulation on the separation flow control of stalled NACA0015 airfoil at high angle of attack (20°) was carried out with synthetic jet actuator in the reeireulation region. The Reynolds averaged Navier-Stoeks equations were solved by commercial computational fluid dynamic software package Fluent6.1. The mechanism of flow separation control with the synthetic jet actuator in the reeireulation region was also discussed by analyzing the vortex structure separated from the airfoil and the flow field near the actuator orifice. When the synthetic jet actuator is in the recirculation region of the airfoil, the separation point on the suction side of the airfoil can be delayed and the reeireulation region can be decreased, which result in the lift enhancement of the airfoil. When the jet orientation is perpendicular to the airfoil wall with the normalized actuator frequency and the jet velocity ratio setting as 1, the lift of the airfoil is increased by about 40%.