A Note on Helmholtz Attenuators with Air Cavity and Membrane

In this paper, we present an analytical expression for the resonance frequency of Helmholtz attenuators with air cavity and membrane. We derive the characteristic equations based on one-dimensional isentropic acoustic models and illustrate the eeects on the resonance frequency of certain design variations. 1 INTRODUCTION The development of high speed paper machines requires a better control of pressure pulsation in approach ow systems. The design of current pressure pulsation attenuators can signiicantly reduce pressure variations, however, they also have been found to be ineeective in dealing with low frequency pulsations (< 1 Hz). The basic design concept of the attenuator used in the paper industry is the Helmholtz resonator. The characteristic property of such a resonator is its ability to eeectively absorb pressure waves around a particular frequency, i.e., the so-called resonant frequency. As one of the fundamental acoustic devices, the Helmholtz resonators have been studied extensively (2) (3) (5). The purpose of this paper is to present an analytical study of the resonance frequency for a particular Helmholtz resonator used in the paper industry.