Turning flight simulation of tilt-rotor plane with fluid-rigid body interaction

Abstract

Six degrees of freedom turning flight simulation is presented for a tilt-rotor aircraft represented by V-22 Osprey, considering interaction of fluid and rigid body in a coupled manner. A tilt-rotor aircraft has a hovering function like a helicopter by turning axes of rotor toward the sky during takeoff or landing. On the other hand, it behaves as a reciprocating aircraft by turning axes of rotor forward in flight. The tilt-rotor aircraft is known to be susceptible to instable state compared to conventional aircraft. For realizing Digital Flight of turning flight of the aircraft, combination with the Moving Computational Domain (MCD) method and the multi-axis sliding mesh approach is applied. In the MCD method, the whole of the computational domain itself moves with the bodies included inside the domain, which makes an airplane possible to fly freely in the physical space without any restriction of region size. Moreover, this method is also applied to rotation of rotors. The multi-axis sliding mesh approach is computational technique to enable us to deal with multiple rotating axes of different direction, and it is used to rotate two rotors and change flight attitude of the aircraft. As a result of the coupled computation between flow field and rigid body using above approach, the airplane gained lift and propulsion by rotating the rotor and flew in turning by operating flight control surfaces such as flaperons, elevator and rudders. Moreover, the manipulating variables of flight control surfaces needed for turning flight, flight attitude of the aircraft and generated lift were found. Differences of fluid flow between straight flight and turning flight were also captured.