hal-00974778
https://hal-ensta-paris.archives-ouvertes.fr/hal-00974778
arxiv:0907.5562
doi:10.1137/09077237X
[ENSTA] ENSTA Paris
[CNRS] CNRS - Centre national de la recherche scientifique
[INRIA] INRIA - Institut National de Recherche en Informatique et en Automatique
[INRIA-SACLAY] INRIA Saclay - Ile de France
[INSMI] CNRS-INSMI - INstitut des Sciences Mathématiques et de leurs Interactions
[INRIA_TEST] INRIA - Institut National de Recherche en Informatique et en Automatique
[TESTALAIN1] TESTALAIN1
[UMA_ENSTA] Unité de Mathématiques Appliquées (UMA)
[INRIA2] INRIA 2
Analysis of Acoustic Wave Propagation in a Thin Moving Fluid
Joly, Patrick
Weder, Ricardo
[MATH] Mathematics [math]
ART
We study the propagation of acoustic waves in a fluid that is contained in a thin two-dimensional tube and that it is moving with a velocity profile that depends only on the transversal coordinate of the tube. The governing equations are the Galbrun equations or, equivalently, the linearized Euler equations. We analyze the approximate model that was recently derived by Bonnet-Bendhia, Durufle, and Joly to describe the propagation of the acoustic waves in the limit when the width of the tube goes to zero. We study this model for strictly monotonic stable velocity profiles. We prove that the equations of the model of Bonnet-Bendhia, Durufle, and Joly are well posed, i.e., that there is a unique global solution, and that the solution depends continuously on the initial data. Moreover, we prove that for smooth profiles the solution grows at most as t(3) as t -> infinity, and that for piecewise linear profiles it grows at most as t(4). This establishes the stability of the model in a weak sense. These results are obtained by constructing a quasi-explicit representation of the solution. Our quasi-explicit representation gives a physical interpretation of the propagation of acoustic waves in the fluid and provides an efficient way to compute the solution numerically.
2010
en
SIAM Journal on Applied Mathematics
Society for Industrial and Applied Mathematics