Helmholtz Resonator Impedance Model, Part 1: Nonlinear Behavior

Abstract

A one-dimensional preliminary design impedance prediction model is derived for Helmholtz resonators constructed with circular orie ces. The model addresses only the effects of resonator geometry and incident sound-pressure amplitude. The effects of grazing e ow are not included. An experimental program was conducted to calibrate unknown empirical parameters derived in the model. The model was shown to predict, reasonably accurately, impedance data published in the open literature for resonators constructed with single and multiple orie ces over a wide range of sound-pressure amplitudes and frequencies. The model provides a rapid means of calculating resonator impedance as a function of resonator geometry, incident sound-pressure amplitude, and frequency.