Jet noise prediction based on a self-adjoint operator
Résumé
The adjoint method introduced by Tam and Auriault [1]enables the proper taking into account of acoustic propa-gation effects when jet noise is modelled from the statisticsof a turbulent flow. This technique is recast in a systematicway valid for arbitrary propagation media, linear operatorsand sound sources. An acoustic analogy based on Pierce’swave equation for the acoustic potential [2] is proposedand Tam and Auriault’s mixing noise model [3] is refor-mulated for this operator. This formulation presents threemain advantages; no instability wave can occur since theacoustic energy conservation is enforced, then for beingself-adjoint the adjoint solution to the propagation prob-lem may straightforwardly be computed by flow reversal,finally Pierce’s wave equation is a simple and cheap equa-tion that several existing solver are able to solve. Workperformed withFFT’s softwareActran TMis presentedillustrating the ability of a commercial tool to solve thisequation and to compute adjoint Green’s function requiredin statistical jet noise modelling.
Origine | Accord explicite pour ce dépôt |
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