The method of solving the Navier-Stokes (RANS) equation by the sliding mesh technique was studied

and the interaction problem of the coaxial rigid rotor/fuselage was analyzed. The correctness of the numerical simulation of the flow field related to rotor was verified by the examples of Caradonna-Tung rotor

Robin helicopter

Maryland helicopter rotor/fuselage interaction

and Harrington 2 coaxial rotors. On this basis

with the Maryland fuselage as the model prototype

the interference characteristics between the coaxial rigid rotor with different pitches and the fuselage were analyzed. Results showed that numerical simulation method can simulate the aerodynamic interference characteristics of the coaxial rigid rotor/fuselage very well; the hovering efficiency of the rotor increased by about 5% due to the blockage of the airflow field of the coaxial rigid rotor.

and the increase of the hovering efficiency was more obvious with the increase of the pulling coefficient; the increase of the hovering efficiency of the rotor was mainly related to the increase of the blade lift coefficient near the 0° azimuth of the lower rotor

and the increment of the tensile coefficient was gradually reduced from the root of the blade to the tip of the blade.