Application of the Prediction Code of the Helicopter Rotor Noise ROTAC to a Real-Size Helicopter: Comparison of Calculations with Measurements

摘要

The acoustic detection of aircraft is a crucial problem for the national defenseauthorities. This paper presents the application of the ROTAC code to one real-size helicopter in hover and forward flights. The acoustic signatures measured at Dreux-Senoches are compared with the thickness noise ones calculated by running the ROTAC code for the main rotor of the helicoptor. The flight cases presented in this paper have been chosen on purpose as the meteorological fluctations seemed to be relatively steady because the computation does not take into account these effects during the acoustic propagation.