Near Real-Time Simulation of Rotorcraft Acoustics and Flight Dynamics

In this paper, a near-real time rotorcraft flight dynamics–acoustics prediction system is presented. Limited internal consistency checks and comparison with previous maneuver noise predictions, based on CAMRAD 2 airloads and motions, are presented to partially validate the system. A complex 80-second maneuver was used to demonstrate the capability of the coupled GENHEL–PSU-WOPWOP system. This realistic maneuver includes a climb, coordinated turn, and level flight conditions. Prediction of overall sound pressure level was performed over a region 2000 meters by 1600 meters with 8181 individual measurement locations. The noise predictions show changes in noise radiation strength and directivity due to maneuver transients, aircraft attitude changes, and the aircraft flight. A comparison of the total noise with the thickness and loading noise components helps explain the noise directivity. The computations for a single observer were very fast—although not real-time. Real-time loading noise prediction is demonstrated and the feasibility of real-time noise prediction of the total noise signal is evaluated.