Interactive aerodynamic characteristics of canard rotor wing aircraft in helicopter forward flight

Compared with the traditional helicopter, the aerodynamic interaction of rotor wing, fuselage, canard and horizontal tail of canard rotor wing (CRW) aircraft in forward flight is severer. In order to get better understanding of the unsteady aerodynamic interaction, the moving structural chimera grid is used to model the moving rotor and three-dimensional unsteady Reynolds averaged Navier-Stokes (URANS) equations are solved to simulate the flow fields of rotor in forward flight. The traditional helicopter's rotor-body interaction model is computed first to validate the method. Then the analyses on rotor wing/fuselage/canard/horizontal tail/vertical tail interactive flow field for an unmanned CRW aircraft in helicopter forward flight are given using the present method. The variations of unsteady aerodynamic forces and moments of the rotor-wing, fuselage, canard, horizontal tail and vertical tail with respect to the rotor azimuth are obtained. The result shows that the fuselage and other components have little effect on the rotor wing, resulting in a slight increase in thrust; the rotor wing has almost no impact on the aerodynamics of canard and vertical tail, but does have strong interference on fuselage and horizontal tail. The horizontal tail produces large vertical force and nose-up pitching moment as the forward flight speed increases, to which great attention should be paid. The research could provide some guidance for the design of a CRW aircraft.