Numerical study on aerodynamic characteristics of two-dimensional propulsive wing in cruise and hover

The propulsive wing vehicle is a new concept vehicle, which is driven by a cross-flow fan (CFF) embedded in the trailing edge of the wing. The propulsive wing vehicle is capable of cruising and hovering at high angles of attack with very high aerodynamic force coefficients, and has the potential to become a new type of vertical take-off and landing (VTOL) vehicle. The cruise and hover states of the propulsive wing vehicle are defined, and a numerical model of the two-dimensional propulsive wing is established. Based on the computational fluid dynamics (CFD) method, the rotation of the CFF is simulated by using the sliding mesh technique. The effects of cruise speed, angle of attack and CFF rotation speed on the aerodynamics of the two-dimensional propulsive wing are evaluated, and the mechanism of the propulsive wing flow field changes is revealed. The results show that the propulsive wing has a very high lift coefficient of up to 60 at low speed and high angle of attack cruise, and a high thrust coefficient of up to 40 at low speed and small angle of attack cruise. The aerodynamic force of the propulsive wing fluctuates periodically with the rotation of the CFF, and the amplitude of the fluctuation is related to the vorticity of the CFF blade shedding vortex. In hover, the flow field of the propulsive wing is affected by the geometry and wake deflection into an asymmetric distribution, forming a vortex on each side of the airfoil, and the vortex diameter varies with the CFF rotation speed, which in turn has an impact on the hovering performance of the propulsive wing.