微型射流涡流发生器对边界层控制的数值研究

NUMERICAL INVESTIGATION OF BOUNDARY-LAYER CONTROL USING MINUTE JET VORTEX GENERATOR

运用数值方法,研究了展向分布的倾斜微型射流列对平板湍流边界层的作用,验证了利用微型射流列产生流向涡列来进行边界层控制的可行性,并分析了射流列各主要参数对控制作用的影响。当各射流同向倾斜时,顺射流倾斜方向流向涡控制作用逐个减弱;当相邻射流反向倾斜时,流向涡列在较大流向区域内对边界层形成较均匀的控制。随射流间距减小,流向涡列初始控制作用增强,但流向控制区域减小。在射流速度较小情况下,随射流速度提高,流向涡列控制作用增强;但过高的射流速度会导致流向涡列穿透边界层,反而导致控制作用下降。采用俯仰角较小(一般小于30°)、倾斜角较大(一般大于60°)的微型射流列对流向涡列控制作用有利。

The effect of spanwise-arranged inclined minute jets on the turbulent flat-plate boundary layer is investigated numerically, and it is confirmed that such minute jets can produce streamwise vortices to control boundary layer. The influences of jet primary parameters on the control action are analyzed. When the skew directions of jets are one, the control action of streamwise vortices weakens one by one along the skew direction; while the skew directions of neighbor jets are contrary, the control action is more uniform in a larger streamwise extent. With the jet spacing decreasing, the initial control action of streamwise vortices improves, but the control action fades more quickly downstream. Under lesser jet velocity, higher jet velocity brings better control action of streamwise vortices; while excessively high jet velocity leads poor control action instead due to streamwise vortices penetrating through boundary layer. Lower jet pitching angle （generally less than 30°） and higher jet skew angle （generally larger than 60°） are helpful to the control action of streamwise vortices.