Acoustic seminar | 12 December 2024

Nonlinear wave propagation plays an important role in many applications, including ultrasonic focusing and musical sound production, among others. In particular, the spectral enrichment ("brassiness") in the sound generation of brass musical instruments is a result of nonlinear propagation inside the bore. From a computational point of view, the simulation of nonlinear acoustic propagation is challenging, as the field quantities become discontinuous in the presence of shocks.

In this talk, unidimensional computational models of weakly nonlinear acoustic propagation are examined, focusing on applications in musical acoustics. We compare a finite volume-based solution of the Menguy-Gilbert model to a finite element implementation of Kuznetsov's equation. The  numerical dispersion and dissipation are evaluated first in the linear regime. Then, the nonlinear behavior is assessed by simulating shock formations and reflections. Finally, possibilities of extending the models by additional effects such as thermoviscous losses at the walls or coupling to an excitation mechanism are discussed.