低雷诺数下协同射流关键参数对翼型气动性能的影响

协同射流是一种高效的新型主动流动控制技术，至今缺乏关键参数对翼型气动性能影响规律的系统研究。通过引入螺旋桨激励盘模型，发展了一种新的协同射流翼型流动模拟方法，使得射流反作用力计算更符合实际。在低雷诺数条件下，以NACA6415为基准翼型开展了射流动量系数、开口尺寸和位置等关键参数对翼型气动性能的影响规律研究，并探讨了相应的物理机制。结果表明：大迎角分离流状态下，射流动量系数对翼型气动性能的影响规律比小迎角附着流状态更复杂；随着吹气口尺寸增加，气泵功率系数先减后增，有效升阻比先增后减；随着吸气口尺寸增加，气泵功率系数逐渐减小，有效升阻比先增加后趋于平稳；吹/吸气口位置对翼型气动性能和气泵功率系数的影响很小。

Influence of co-flow jet key parameters on airfoil aerodynamic performance at low Reynolds number

Co-flow jet is an efficient and novel active flow control technology. There is no systematic study on the influence of key parameters of co-flow jet on airfoil aerodynamic performance. By introducing the actuator disk model of propeller, a new method for simulation of the flow around the co-flow jet airfoil is developed, resulting in a more practical method for calculating the jet reaction force. Under the condition of low Reynolds number, the effects of key parameters, including jet momentum coefficient, opening size and opening location, on the aerodynamic performance of the NACA6415 airfoil are studied, and the corresponding physical mechanism is discussed. The results demonstrate that compared to the attached flow at small angle of attack, the influence of jet momentum coefficient on aerodynamic performance is more complicated for the separated flow at larger angle of attack. With the increase of injection size, the pump power coefficient decreases first and then increases, the effective lift to drag ratio increases first and then decreases. As the suction size increases, the pump power coefficient gradually decreases, and effective lift to drag ratio increases first and then tends to be stable. The location of the injection and suction has little effects on both the aerodynamic performance of the airfoil and the pump power coefficient.