A.S. Hersh, B.E. Walker

A non linear fluid mechanical-lumped element hybrid model of the acoustic behavior of Helmholtz resonators has been derived. Both data and model show that resonator resistance is very sensitive to incident sound pressure amplitude in a frequency range centered at its tuned frequency. At frequencies very much below or above resonance, the resistance becomes independent of SPL, the so-called linear regime. The nonlinear behavior of Helmholtz resonators was modeled in terms of empirical nonlinear acoustic discharge coefficients and lumped element end correction parameters. Both parameters were correlated in terms of the characteristic velocities [omega]de and [formula omitted]. Despite the intense nonlinear orifice jetting at high sound pressure amplitudes, both data and the model show that the reactance has a profound effect upon the resonator resistance but the resistance only negligibly affects resonator reactance. The negligible coupling between nonlinear resistance and resonator reactance permits the partition of reactance into the familiar inertial and stiffness components. The tuned or resonant frequency is only weakly dependent upon SPL. The hybrid impedance model was validated by the close agreement between predicted and measured impedance of a large number of resonators over a large sound pressure amplitude and frequency range.

First Joint CEAS/AIAA Aeroacoustics Conference, München, 1995

Conference Paper

englisch

21,0 x 29,7 cm, 10 Seiten

DGLR-Bericht, 1995, 1995-01, First Joint CEAS/AIAA Aeroacoustics Conference - Proceedings; S.585-594; 1995; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroacoustics, helmholtz resonators

Bibliothek

1995