Numerical Simulation of Noise Characteristics of Open Rotor

Abstract

In order to investigate the noise characteristics of open rotor, numerical simulation was performed for an open rotor which contains 11 blades for the front row and 9 blades for the rear row. The aerodynamic noise of the open rotor was compared with a single propeller, i.e. the front row propeller. Numerical results show that predicted noise field results agree well with the literature. The noise spectrum of the open rotor is obviously more complex and higher than that of the single propeller. In addition, the contribution of different noise generation mechanisms was studied for the interaction noise. Results show that the blade tip vortex interaction noise and the wake interaction noise are the main noise generation mechanisms while the hub vortex interaction noise contributes less to the interaction noise. Blade tip vortex interaction noise and wake interaction noise need to be paid more attention. The investigation result may help to develop relevant noise reduction techniques for the open rotor.