Investigation on Aerodynamic Noise Characteristics of Coaxial Rotor in Hover

A numerical method based on Reynolds Averaged Navier–Stokes (RANS) equations and a high-efficiency trim model is developed to simulate the aerodynamics of coaxial rotor. Farassat 1A are used for prediction thickness loading noise. Hover cases different thrust coefficients with torque balance conducted. The sound pressure history observation points positioned below rotor disk plane analyzed. Results indicate that special noise characteristics mainly caused by superposition twin rotors unsteady loads aerodynamic interaction. new kind impulsive induced blade-meeting In contract single rotor, has much larger level in high-frequency band. obviously enhanced around azimuths. maximum located immediately center, while it minimum location.