Numerical analysis and active control of wake/blade-row interaction noise

Abstract

A computational approach for investigating and controlling the wake/blade-row interaction noise through the use of actuators or blowing/suction on the stator blade surfaces is presented in this paper. This approach includes a solution-adaptive finite volume upwind scheme, adaptive/dynamic mesh technique, boundary treatments for aeroacoustic computations, and an active noise control algorithm. A two-dimensional section of a fan stage, which is composed of an upstream rotor and a downstream fan exit guide vane (FEGV), is investigated. By utilizing a rotor wake model, the acoustic fields of the FEGV are presented and analyzed to understand the accuracy and suitability of the present adaptive scheme. Also, the noise generation mechanics are studied. Finally, the active noise control algorithm is introduced. From the computational results, the reduction of noise due to actuators on the blade surfaces is more significant than that of using blowing/suction. The downstream propagating acoustic waves are more difficult to control than the upstream propagating waves. [Work supported by NSC.]