微飞行器前后同频双扑动翼的推进效果

Propulsive effects of same frequency dual flapping airfoils in a micro air vehicle

为了解微飞行器前后双扑动翼的推进效果,该文通过在动态网格上求解Navier-Stokes方程,对前翼扑动后翼静止、前后翼同相扑动和前后翼反相扑动3种运动方式的流场进行了数值模拟和气动干扰的分析。前翼扑动后翼静止,其推力系数和推进效率比单翼扑动分别增加65%和44%;前后翼同相扑动时产生的推力甚至超过单翼扑动的2倍;但前后翼反相扑动时,推力大大减小,不足同相扑动的一半。结果表明,处于前翼扑动尾流中的后翼对气动特性影响很大。

Dual flapping airfoils in tandem configurations have better propulsive efficiency than single flapping airfoils. The unsteady viscous flow fields around dual flapping airfoils in tandem configurations were simulated by a Navier-Stokes solver using dynamic deformable hybrid meshes. The aerodynamic interactions of three motion models were studied including a flapping fore airfoil with a fixed aft airfoil and two airfoils flapping in phase and out-of-phase. With a flapping fore airfoil and a fixed aft airfoil, the thrust coefficient increased by 65% over a single flapping airfoil and the thrust propulsive efficiency increased by 44%. When the two airfoils moved in phase, the thrust generation was twice that of a single flapping airfoil. However, the out-of-phase motion produced much lower thrust which was less than half in phase. The results indicate that the aft airfoil in the wake of the flapping fore airfoil greatly influences on the aerodynamic performance.