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Computational Aeroacoustics Based on Large Eddy Simulation and Acoustic Analogies

Mihaescu, Mihai LU (2005)
Abstract
The thesis presents a numerical method developed by the author and its applications for computing the generated sound by an unsteady flow field and its propagation.



The full equations of motion for compressible and unsteady flows describe both flow field and sound generation and propagation. It is assumed that the flow variables can be decomposed into semi-compressible / incompressible components and inviscid, irrotational acoustic components. The present method is based on Large Eddy Simulation (LES) to compute the turbulent flow and an approach based on an inhomogeneous wave equation to compute the radiated acoustic field. In this way one can avoid the necessity for a very large computational effort associated with... (More)
The thesis presents a numerical method developed by the author and its applications for computing the generated sound by an unsteady flow field and its propagation.



The full equations of motion for compressible and unsteady flows describe both flow field and sound generation and propagation. It is assumed that the flow variables can be decomposed into semi-compressible / incompressible components and inviscid, irrotational acoustic components. The present method is based on Large Eddy Simulation (LES) to compute the turbulent flow and an approach based on an inhomogeneous wave equation to compute the radiated acoustic field. In this way one can avoid the necessity for a very large computational effort associated with direct simulation of the near- and specially far- field sound generated by a turbulent flow. The governing equations are written in the form of a non-homogeneous wave equation for the acoustic fluctuation with acoustic sources on the right-hand side. The thesis includes the details of the coupling between the flow solver and the acoustic one, as well as the results for test cases employed to validate the numerical algorithm and the implemented boundary conditions.



The method has been successfully applied to compute the near- and far- acoustic fields generated by various unsteady flows such as a round hot turbulent jet ejected from a pipe close to a solid boundary, coaxial turbulent non-isothermal jets (separate exhaust system), or the flow around a wind-turbine. (Less)
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author
supervisor
opponent
  • Professor Sorensen, Jens N., Technical University of Denmark (DTU)
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Mechanical engineering, hydraulics, plasma, Technological sciences, Teknik, fluiddynamik, plasmas, Gaser, fluid dynamics, Gases, Inhomogeneous Wave Equation, Acoustic Boundary Conditions, Acoustic Source Terms, LES, Computational Aeroacoustics, Turbulent Flows, vacuum technology, vibration and acoustic engineering, Maskinteknik, hydraulik, vakuumteknik, vibrationer, akustik
pages
215 pages
publisher
KFS AB
defense location
Room M:E, M-building, Ole Römers väg 1, Lund Institute of Technology
defense date
2005-04-14 13:15
external identifiers
  • other:ISRN: LUTMDN/TMHP--05/1030--SE
ISSN
0282-1990
ISBN
91-628-6443-2
language
English
LU publication?
yes
id
882be64e-2cc2-4230-a7d1-7231d9b1fc94 (old id 544563)
date added to LUP
2007-10-13 12:43:22
date last changed
2016-09-19 08:44:59
@phdthesis{882be64e-2cc2-4230-a7d1-7231d9b1fc94,
  abstract     = {The thesis presents a numerical method developed by the author and its applications for computing the generated sound by an unsteady flow field and its propagation.<br/><br>
<br/><br>
The full equations of motion for compressible and unsteady flows describe both flow field and sound generation and propagation. It is assumed that the flow variables can be decomposed into semi-compressible / incompressible components and inviscid, irrotational acoustic components. The present method is based on Large Eddy Simulation (LES) to compute the turbulent flow and an approach based on an inhomogeneous wave equation to compute the radiated acoustic field. In this way one can avoid the necessity for a very large computational effort associated with direct simulation of the near- and specially far- field sound generated by a turbulent flow. The governing equations are written in the form of a non-homogeneous wave equation for the acoustic fluctuation with acoustic sources on the right-hand side. The thesis includes the details of the coupling between the flow solver and the acoustic one, as well as the results for test cases employed to validate the numerical algorithm and the implemented boundary conditions.<br/><br>
<br/><br>
The method has been successfully applied to compute the near- and far- acoustic fields generated by various unsteady flows such as a round hot turbulent jet ejected from a pipe close to a solid boundary, coaxial turbulent non-isothermal jets (separate exhaust system), or the flow around a wind-turbine.},
  author       = {Mihaescu, Mihai},
  isbn         = {91-628-6443-2},
  issn         = {0282-1990},
  keyword      = {Mechanical engineering,hydraulics,plasma,Technological sciences,Teknik,fluiddynamik,plasmas,Gaser,fluid dynamics,Gases,Inhomogeneous Wave Equation,Acoustic Boundary Conditions,Acoustic Source Terms,LES,Computational Aeroacoustics,Turbulent Flows,vacuum technology,vibration and acoustic engineering,Maskinteknik,hydraulik,vakuumteknik,vibrationer,akustik},
  language     = {eng},
  pages        = {215},
  publisher    = {KFS AB},
  school       = {Lund University},
  title        = {Computational Aeroacoustics Based on Large Eddy Simulation and Acoustic Analogies},
  year         = {2005},
}