Nonlinear acoustics in a general 3D duct #

Freddie Jensen, Ed Brambley

11:50 Monday in 4Q05.

Part of the Acoustics session.

Abstract #

The aim of this project is to reproduce and build upon the work of McTavish, J. P. (2019) in modelling nonlinear sound propagation in 3D waveguides, with an application to the harmonic series of brass instruments. Time-harmonic perturbations about a state of rest are considered up to second order (weak nonlinearity). The governing equations for weakly nonlinear sound are then projected onto a basis of straight, cylindrical duct modes before the consideration of the duct outlet physics. Eventually the impedance along the duct is calculated for various geometries and endpoint conditions; this can be informative as to the harmonic series of a brass instrument, for example.