P. di Francescantonio

A numerical method for the prediction of the surface component of the quadrupole term of the F.W.H. equation is presented. Since its ability to execute integrals on deformable surfaces the proposed method is naturally applied to the prediction of shock wave noise, but can also be used for the wake and the blade itself. The problem of the integration on a deformable surface is solved using a finite-element-like schematization that automatically allows to execute a local mapping of the deformable panels into indeformable elements on which the integration is executed. This approach seems to present some advantages in respect of a global mapping of the surface, since there is no more the need of an external code to perform the mapping, and since the shock wave has no more to remain topologically equivalent during the motion. The use of an isoparametric approach allows besides to use an efficient description of the retarded values of all the quantities defined inside the panel. Since the knowledge of the surface curvature is required, high order panels are used, and a method to obtain the surface curvature in function of the positions of the nodes is derived. The method even if is specialized. for the prediction of the shock wave noise, can be seen as a general approach that allows the evaluation of all the surface terms of the F.W.H equation with an unique formulation.

DGLR/AIAA 14th Aeroacoustics Conference, 1992

Conference Paper

englisch

21,0 x 29,7 cm, 10 Seiten

DGLR-Bericht, 1992, 1992-03, DGLR/AIAA 14th Aeroacoustics Conference - Proceedings; S.714-723; 1992; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroacoustics, ffowcs william-hawkings equation

Bibliothek

1992