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Comparison of computational aeroacoustics with theory using the benchmark case of sound waves excited from a semi‐infinite duct
Author(s) -
Morgenweck Daniel,
Schemel Christoph,
Thiele Frank
Publication year - 2004
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.200410245
Subject(s) - duct (anatomy) , infinitesimal , computational aeroacoustics , aeroacoustics , rotational symmetry , benchmark (surveying) , acoustics , sound propagation , mechanics , sound pressure , physics , mathematics , mathematical analysis , geology , medicine , geodesy , pathology
In this paper the benchmark problem of radiation from a semi infinite duct is discussed. The duct is modeled by an infinitesimal thin wall. Comparisons are made between the analytic solutions of R. M. Munt and the 2 nd CAAWorkshop with our CAA‐code. In all cases a 3D axisymmetric approach is chosen to describe the propagation of a single mode. The procedure consists of two steps. Step 1 concerns a numerical simulation of the near‐field‐region. Step 2 calculates the farfield‐solution by means of the acoustic‐analogy of FfowcsWilliams and Hawkings. Since the wall is of infinitesimal thickness, the edge needs to be treated in a special way. Two different approaches are persecuted and the results are compared. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)