Improved multimodal formulation of the wave propagation in a 3D waveguide - Archive ouverte HAL Access content directly
Conference Papers Year : 2020

Improved multimodal formulation of the wave propagation in a 3D waveguide

, (1) , (2) , (3) , (4)
1
2
3
4
Thomas Guennoc
  • Function : Author
Jean-Baptiste Doc
Agnès Maurel

Abstract

The standard multimodal formulation in waveguides consists in discretizing the transverse problem into transverse modes, so that the solving can be reduced to the one longitudinal dimension. In addition to provide an efficient numerical method, one of the main advantages of this method is to provide a direct access to the physical quantities that are relevant to the understanding of the problem, such as impedances and scattering coefficients. In 3D waveguides with circular cross-section, the Bessel's function satisfying Neumann boudary conditions are naturally chosen to be the transverse modes of the waveguides. They indeed have the useful property of being uncoupled in the straight parts of the guide. However, they do not have the ability to fulfill the exact boundary condition in the varying radius parts of the waveguide, as the radial vector is no longer the normal vector to the wall. This has a strong impact on the convergence, that is significantly lowered. To tackle this issue, we add an orthogonalized boundary mode to our transverse basis (hence the *improved* multimodal formulation), that makes the fulfilling of the boundary condition at the wall much easier. As we will show in our presentation, this both keeps the propagation equation unchanged and restores the fast convergence.
Not file

Dates and versions

hal-03240342 , version 1 (28-05-2021)

Identifiers

Cite

Thomas Guennoc, Jean-Baptiste Doc, Simon Félix, Agnès Maurel, Jean-François Mercier. Improved multimodal formulation of the wave propagation in a 3D waveguide. Forum Acusticum, Dec 2020, Lyon, France. pp.1875-1875, ⟨10.48465/fa.2020.0892⟩. ⟨hal-03240342⟩
53 View
0 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More