Article
Examination of computational models of weakly nonlinear sound propagation in ducts (en)
* Presenting author
Abstract:
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. Techniques such as shock capturing, flux limiting, and artificial dissipation can be used for treating shock waves in numerical solutions. This contribution investigates unidimensional computational models of weakly nonlinear acoustic propagation, focusing on applications in musical acoustics. We compare the performance of a finite volume-based solution of the Menguy-Gilbert model to a finite element implementation of Kuznetsov's equation. Both models are validated first in the linear case, where numerical dispersion and dissipation are evaluated. 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.