Aeroacoustics Research in Europe: 5.1 Tail Rotor Noise Under Main/Tail Rotor Interaction

To demonstrate the effects of main rotor (MR) and tail rotor (TR) mutual interaction on the aerodynamics and noise characteristics, a BO105 MR/TR configuration is chosen in the numerical simulations. A Main and Tail rotor Interaction Code (UPM-MANTIC) (Ref. 1) based on Unsteady free wake 3-D Panel Method is used to account for the mutual aerodynamic interference between MR and TR. The unsteady pressure on the MR and TR blade is calculated with (UPM-MANTIC and used as input to another DLR aeroacoustic code (APSIM = Aeroacoustic Prediction System based on Integral Method) to calculate rotor noise. Free wake and rotor noise computations were performed to study the effect of MR/TR mutual interaction on rotor wake development, blade loads and noise radiation. With the special emphasis on tail rotor noise, a climb flight is simulated