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Comparison of outflow boundary conditions for subsonic aeroacoustic simulations
Author(s) -
Fosso P. A.,
Deniau H.,
Lamarque N.,
Poinsot T.
Publication year - 2011
Publication title -
international journal for numerical methods in fluids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 112
eISSN - 1097-0363
pISSN - 0271-2091
DOI - 10.1002/fld.2597
Subject(s) - aeroacoustics , computational aeroacoustics , aerodynamics , vortex , euler equations , boundary value problem , physics , boundary (topology) , euler's formula , mechanics , acoustics , mathematics , mathematical analysis , sound pressure
SUMMARY Aeroacoustics simulations require much more precise boundary conditions than classical aerodynamics. Two classes of non‐reflecting boundary conditions for aeroacoustics are compared in the present work: the characteristic analysis‐based methods and the Tam and Dong approach. In the characteristic methods, waves are identified and manipulated at the boundaries, whereas the Tam and Dong approach use modified linearized Euler equations in a buffer zone near outlets to mimic a non‐reflecting boundary. The principles of both approaches are recalled, and recent characteristic methods incorporating the treatment of transverse terms are discussed. Three characteristic techniques—the original Navier–Stokes characteristic boundary conditions (NSCBC) of Poinsot and Lele and two versions of the modified method of Yoo and Im—are compared with the Tam and Dong method for four typical aeroacoustics problems: vortex convection on a uniform flow, vortex convection on a shear flow, acoustic propagation from a monopole, and acoustic propagation from a dipole. Results demonstrate that the Tam and Dong method generally provides the best results and is a serious alternative solution to characteristic methods even though its implementation might require more care than the usual NSCBC approaches. Copyright © 2011 John Wiley & Sons, Ltd.