Computation of Aeroacoustic Sound Via Hybrid CFD/CAA-Methods

Abstract

Different formulations for a two step CFD/CAA approach are investigated. The acoustic field is simulated using linearized perturbation equations which are excited by sources determined from the unsteady compressible near field flow. The sound generated by a cylinder in laminar at Mach number M=0.3 and Reynolds number Re=200 is used as a test problem. It is examined whether the viscous/acoustic splitting method of Shen et al., which is based on a simulation of the incompressible flow field, can be adapted to a compressible base flow simulation. It is found that excessive artificial vorticity is generated in the wake of the cylinder due to the excitation of hydrodynamic instabilities. A new set of governing acoustic perturbation equations (APE) is proposed, which includes sources determined from a compressible flow simulation. As shown for the test problem, the occurrence of vorticity is prevented completely since the source solely excites acoustic modes in the APE.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 2003
Accession Number
ADP014109

Entities

People

  • M. Meinke
  • R. Ewert
  • W. Schroder

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Acoustic Fields
  • Acoustic Signals
  • Acoustics
  • Base Flow
  • Compressible Flow
  • Computational Fluid Dynamics
  • Computational Science
  • Dispersion Relations
  • Equations
  • Far Field
  • Incompressible Flow
  • Mach Number
  • Near Field
  • Reynolds Number
  • Simulations
  • Sound Pressure
  • Turbulent Mixing

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.
  • Computational Fluid Dynamics (CFD)
  • Fluid Dynamics.