Non-reflecting boundary conditions for acoustic propagation in ducts with acoustic treatment and mean flow
| Autor: | Jean-François Mercier, Emmanuel Redon, S. Poernomo Sari, A. S. Bonnet-Ben Dhia |
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| Rok vydání: | 2011 |
| Předmět: |
Numerical Analysis
Scattering Applied Mathematics Mathematical analysis General Engineering Boundary (topology) Geometry 01 natural sciences Finite element method Domain (mathematical analysis) 010305 fluids & plasmas 010101 applied mathematics 0103 physical sciences Acoustic propagation Waveguide (acoustics) Mean flow Boundary value problem 0101 mathematics Mathematics |
| Zdroj: | International Journal for Numerical Methods in Engineering. 86:1360-1378 |
| ISSN: | 0029-5981 |
| DOI: | 10.1002/nme.3108 |
| Popis: | We consider a time-harmonic acoustic scattering problem in a 2D infinite waveguide with walls covered with an absorbing material, in the presence of a mean flow assumed uniform far from the source. To make this problem suitable for a finite element analysis, the infinite domain is truncated. This paper concerns the derivation of a non-reflecting boundary condition on the artificial boundary by means of a Dirichlet-to-Neumann (DtN) map based on a modal decomposition. Compared with the hard-walled guide case, several difficulties are raised by the presence of both the liner and the mean flow. In particular, acoustic modes are no longer orthogonal and behave asymptotically like the modes of a soft-walled guide. However, an accurate approximation of the DtN map can be derived using some bi-orthogonality relations, valid asymptotically for high-order modes. Numerical validations show the efficiency of the method. The influence of the liner with or without mean flow is illustrated. |
| Databáze: | OpenAIRE |
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