Considering three flights (hover/cruise/transitional mode) of tilt-rotor

numerical simulations on the aerodynamic characteristics of tilt-rotor under different conditions were conducted respectively. Firstly

a multi-layer moving embedded grid method was established. Secondly

the unsteady RANS ( Reynolds averaged Navier-Stokes) equations were taken to simulate the unsteady characteristics of the flowfield around tilt-rotor. In order to improve the computational efficiency

the implicit LU-SGS (lower upper symmetric Gauss Seidel) method and the SPMD (single program multiple data) mode of parallel computing were employed. Finally

based on the grid method generation and flow solver

the aerodynamic characteristics of tilt-rotor under different flight conditions were numerically analysed

proving that the method presented is effective to simulate the aerodynamic characteristics of tilt-rotor. Result shows that

in hover mode

the downwash of the tilt-rotor is more obvious than the helicopter rotor. The aerodynamic interference between the tilt-rotor is apparent when the distance of the tilt-rotor shafts is 2.5R in cruise mode. In the conversion mode

the thrust decreases rapidly before the 45° tilting angle

and the thrust distribution on surface of tilt-rotor blade is similar to the helicopter rotor.