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Aerodynamic characteristics of tilt-rotor UAVs are usually simulated by computational fluid dynamics (CFD) only, and the fuselage/wing is fixed in simulations. It is difficult for this method to consider drastic… Click to show full abstract
Aerodynamic characteristics of tilt-rotor UAVs are usually simulated by computational fluid dynamics (CFD) only, and the fuselage/wing is fixed in simulations. It is difficult for this method to consider drastic changes of the aerodynamic forces and flowfield originating from conversion of flight modes. And during flight-mode conversions, the rapid changes of postures of tilt-rotors will unavoidably bring great influence on aerodynamic characteristics. In addition, the simulation of the control system for flight-mode conversions cannot be realised by CFD only. In this paper, considering the motion of the fuselage/wing and the dynamic tilting process of tilt-rotors, a new computational method by coupling CFD and multi-body dynamics (MBD) is presented for flight-mode conversions of a tilt tri-rotor UAV with the large-space computational domain. The numerical results validate the feasibility of the coupling method and also show effects of the fuselage/wing motion and flight-mode conversions to aerodynamic characteristics of the tilt tri-rotor UAV.