Hybrid methods for airframe noise numerical predic

Authors: M Terracol E Manoha C Herrero E Labourasse S Redonnet P Sagaut

Publish Date: 2005/06/08

Volume: 19, Issue: 3, Pages: 197-227

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Abstract

This paper describes some significant steps made towards the numerical simulation of the noise radiated by the highlift devices of a plane Since the full numerical simulation of such configuration is still out of reach for present supercomputers some hybrid strategies have been developed to reduce the overall cost of such simulations The proposed strategy relies on the coupling of an unsteady nearfield CFD with an acoustic propagation solver based on the resolution of the Euler equations for midfield propagation in an inhomogeneous field and the use of an integral solver for farfield acoustic predictionsIn the first part of this paper this CFD/CAA coupling strategy is presented In particular the numerical method used in the propagation solver is detailed and two applications of this coupling method to the numerical prediction of the aerodynamic noise of an airfoil are presentedThen a hybrid RANS/LES method is proposed in order to perform some unsteady simulations of complex noise sources This method allows for significant reduction of the cost of such a simulation by considerably reducing the extent of the LES zone This method is described and some results of the numerical simulation of the threedimensional unsteady flow in the slat cove of a highlift profile are presented While these results remain very difficult to validate with experiments on similar configurations they represent up to now the first 3D computations of this kind of flow

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