Experimental Research on Reducing Flow-Induced Cavity Resonance with a Narrowband Active Noise Control System

Abstract

In this paper, active control of flow-induced cavity resonance noise is addressed. A hybrid numerical method is presented to predict the resonance frequency and, instead of traditional active flow control, a narrowband active noise control system is utilized to suppress the resonance. A duct system is built up at low Mach numbers and experiments are carried out to validate the proposed methods. The results have shown that the resonance frequency could be predicted with 1.5% errors and the flow-induced narrowband noise could be effectively suppressed at both the fundamental frequency and its first harmonic. More than 10 dB global attenuations could be achieved for the fundamental resonance frequency without noise enhancements at other frequencies. Further, it was also found that the optimal reference frequency of the narrowband active noise control system could be largely biased from the original resonance frequency, which indicates a nonlinear mechanism of the control system.

Research on the Generation Mechanism and Suppression Method of Aerodynamic Noise in Expansion Cavity Based on Hybrid Method

“…The simulations assisted in experimental measurements and verification. An et al [18] constructed an experimental platform to test and analyze cavity resonance noise caused by airflow, and a narrow-band active noise control system was utilized to mitigate cavity resonance noise. Results indicated that the active control system achieved a significant global attenuation of over 10 dB at the fundamental resonance frequency.…”