Nonlinear Acoustic Damping Induced by Gas-Liquid Scheme Injector in an Acoustic Tube

Abstract

Nonlinear acoustic damping induced by gas-liquid scheme injector is investigated numerically by adopting nonlinear analysis. Governing equations describing nonlinear acoustic fields in an acoustic tube or channel are solved simultaneously. The acoustic property of insertion loss is adopted to quantify acoustic damping capacity of the injector or resonator. From the acoustic fields in the acoustic channel with a single resonator, the insertion losses are calculated with two adjustable parameters of the resonator length and sound pressure level. It is validated by the insertion-loss approach that the injector or resonator functions as a half-wave resonator in a non-linear range. From nonlinear responses of the resonator, it is found that damping capacity becomes identical irrespective of the resonator length when high-amplitude acoustic oscillation is excited. Accordingly, damping capacity of a half-wave resonator is degraded by high-amplitude pressure fluctuation and the resonator length does not affect damping capacity of the resonator in nonlinear acoustics.