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The Simulation of Airframe Noise Applying Euler-Perturbation and Acoustic Analogy Approaches

Ewert, R. and Delfs, J.W. and Lummer, M. and Bauer, M. (2004) The Simulation of Airframe Noise Applying Euler-Perturbation and Acoustic Analogy Approaches. In: ECCOMAS 2004, 4th European Congress on Computational Methods in Applied Sciences and Engineering, CD-ROM. ECCOMAS 2004, Jyväskylä (fi), 24.-28.07.2004. ISBN 951-39-1869-6.

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Abstract

The application of perturbation approaches to simulate airframe noise mechanisms of aircraft during landing approach is discussed. Euler-perturbation approaches that simulate sound generation at obstacles due to upstream injected test-vorticity allow to assess the efficiency of a geometry to transform vortical energy into acoustic energy. Acoustic analogies with sources determined either by an unsteady flow simulation or described statistically yield hybrid two-step methods that in addition take into account the turbulent source strength. An acoustic analogy is presented that uses acoustic perturbation equations (APE)for the simulation of the acoustic radiation problem in space and time. The acoustic convection and refraction effects are part of the simulation of wave propagation such that the source domain is limited to the vicinity of the sound generating geometry where the unsteady vorticity has a considerable magnitude. Using linearized acoustic perturbation equations the unbounded growth of hydrodynamic instabilities in critical mean flows is prevented completely. Computational results for trailing edge noise based on a Large Eddy Simulation (LES) of the compressible flow problem and acoustic perturbation equations for the acoustic simulation are presented. The acoustic source terms are computed furthermore from a synthetic turbulence model and first results for trailing edge noise are presented. The far field sound field is computed via Kirchhoff extrapolation.

Document Type:Conference or Workshop Item (Paper)
Additional Information: LIDO-Berichtsjahr=2005,
Title:The Simulation of Airframe Noise Applying Euler-Perturbation and Acoustic Analogy Approaches
Authors:
AuthorsInstitution or Email of Authors
Ewert, R.UNSPECIFIED
Delfs, J.W.UNSPECIFIED
Lummer, M.UNSPECIFIED
Bauer, M.Technische Universität Dresden
Date:2004
Journal or Publication Title:ECCOMAS 2004, 4th European Congress on Computational Methods in Applied Sciences and Engineering
Volume:CD-ROM
Editors:
EditorsEmail
ECCOMAS, UNSPECIFIED
ISBN:951-39-1869-6
Status:Published
Keywords:Airframe Noise, Computational Aeroacoustics (CAA), Acoustic Analogy, Acoustic Perturbation Equations (APE), Stochastic Noise Generation and Radiation (SNGR), Large Eddy Simulation (LES)
Event Title:ECCOMAS 2004, Jyväskylä (fi), 24.-28.07.2004
Organizer:ECCOMAS
HGF - Research field:Aeronautics, Space and Transport (old)
HGF - Program:Aeronautics
HGF - Program Themes:Aircraft Research
DLR - Research area:Aeronautics
DLR - Program:L AR - Aircraft Research
DLR - Research theme (Project):L - Concepts & Integration
Location: Köln-Porz , Braunschweig , Göttingen
Institutes and Institutions:Institute of Aerodynamics and Flow Technology
Deposited By: Claudia Grant
Deposited On:31 Jan 2006
Last Modified:14 Jan 2010 19:46

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