Numerical analyses of acoustic vibrational resonance in a Helmholtz resonator

In this study, the numerical analyses of a system, which describes the motion of air particles in the cavity of a Helmholtz resonator (HR), excited by a sound wave, was conducted. The low-frequency (LF) signal in the acoustic field is amplitude-modulated by an additive high-frequency (HF) perturbation, which can enhance the detection of the low-frequency, through Vibrational Resonance (VR) phenomena. The focus was on the combined effect, of amplitude and frequency of the acoustic excitation, on the motion of particles and induction of resonance. It was demonstrated that the system exhibits several nonlinear behaviours, VR ceasing to exist for a particular motion of the particles, which is dictated by the excitation frequency in relation to the resonator’s geometry. Furthermore, the regimes in which the performance of the system can be optimized, was identified, which facilitated the design of broadband acoustic resonators, suitable for most applications.