Generation of acoustic solitary waves in a lattice of Helmholtz resonators

• Numerical modeling of nonlinear hyperbolic systems with nonlinear relaxation.
• Experimental investigation of nonlinear propagation.
• Validation of a theoretical model involving acoustic solitary waves.

This paper addresses the propagation of high amplitude acoustic pulses through a 1D lattice of Helmholtz resonators connected to a waveguide. Based on the model proposed by Sugimoto (1992), a new numerical method is developed to take into account both the nonlinear wave propagation and the different mechanisms of dissipation: the volume attenuation, the linear viscothermal losses at the walls, and the nonlinear absorption due to the acoustic jet formation in the resonator necks. Good agreement between numerical and experimental results is obtained, highlighting the crucial role of the nonlinear losses. Different kinds of solitary waves are observed experimentally with characteristics depending on the dispersion properties of the lattice.