Numerical Simulation of Bo105 Main/Tail Rotor Interaction Noise And Preliminary Comparisons with Flight Test Results

Abstract

To demonstrate the effects of main rotor (MR) and tail rotor (TR) mutual interaction on the aerodynamics and noise characteristics, a B0105 MR/TR configuration is chosen in the numerical simulations. A MAiN and Tail rotor Interaction Code (MANTIC) 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 surface is calculated with 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. Some results of aerodynamic and aeroacoustic computations are compared with wind tunnel measured data as well as data obtained from a recent flight test at DLR with a fully instrumented BO105 helicopter. A brief description of the flight test procedures and some preliminary flight test results will be provided in this paper. In order to speed up the aerodynamic computation some numerical approximations were introduced in the simulation and the effects of these numerical approximations on the computational results are studied.