Analysis of Rotor Noise during Maneuvering Flight based on CLORNS Solver

Based on FW-H equations and the CFD method, aeroacoustic characteristics of rotor during collective pitch aperiodic variation are calculated and analyzed. At first, a set of analysis method for aperiodic rotor aeroacoustic characteristics is developed. The aerodynamic and aeroacoustic characteristics of BO-105 rotor in hover and NACA rotor in a ramp increase of collective pitch are calculated, and the employed numerical analysis method is validated through comparisons with experimental data. Then, the aeroacoustic characteristic of BO-105 rotor in hover and in forward flight during collective pitch aperiodic variation is calculated. Finally, parameters, such as the collective pitch change rate, are quantified, and some conclusions are obtained.