Absorptive Characteristics of a Helmholtz Resonator Damped by a Flexible Porous Screen

유연한 다공성 스크린을 가진 헬름홀쯔 공명기의 흡음특성

A Helmholtz resonator is one of noise control elements widely used in many practical applications. The resonator has very high absorption at resonance frequency but the frequency bandwidth is very small. Therefore many kinds of additional resistive screens have been applied to the resonator's neck in order to increase the bandwidth. This paper discusses the absorptive characteristics of a Helmholtz resonator damped by a flexible porous screen in form of wire mesh. First, various experimental results are introduced and studied. Secondly, the effect of the resistive screen is theoretically predicted. It is shown that the distance between the screen and aperture affects on the resonance frequency as well as the absorption of the system.