Abstract：A numerical simulation model is established by CFD method for quad tilt rotor aircraft in conversion state. The method can be used to calculate and analyze the aerodynamic characteristics. Firstly, based on the momentum source method, the lift force and power of the isolated rotor are calculated and compared with the experimental results, and the effectiveness of the momentum source method is verified. Then the aerodynamic interference calculation model of the whole aircraft is established, in which the rotors are represented by momentum source and divided by structured grids, and the unstructured grids are applied to the fuselage, wings and nacelles. Finally, the aerodynamic interference characteristics of the rotors and the wings in conversion state are analyzed, some aerodynamic interference laws are obtained and the aircraft overall design is supported.
