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Numerical Simulations of Turbulent Flows at Widely Different Mach Numbers

Moroianu, Dragos LU (2005)
Abstract
The present thesis mainly focuses on the numerical simulation of the turbulent flow field and acoustics developed in different industrial applications. The study covers a large range of Mach numbers, starting from incompressible regimes and ending with a fully compressible flow.



In the first part of the thesis, several computations of an incompressible flow, are performed in order to study the behavior of an aircraft engine running close to the ground. The ground vortex interaction and particle ingestion are the investigated topics. The methods involved for solving the flow are the Reynolds Averaged Navier Stokes with a k-epsilon turbulence model closure, Large Eddy Simulation with Smagorinsky sub grid scale model. The... (More)
The present thesis mainly focuses on the numerical simulation of the turbulent flow field and acoustics developed in different industrial applications. The study covers a large range of Mach numbers, starting from incompressible regimes and ending with a fully compressible flow.



In the first part of the thesis, several computations of an incompressible flow, are performed in order to study the behavior of an aircraft engine running close to the ground. The ground vortex interaction and particle ingestion are the investigated topics. The methods involved for solving the flow are the Reynolds Averaged Navier Stokes with a k-epsilon turbulence model closure, Large Eddy Simulation with Smagorinsky sub grid scale model. The particle ingestion problem is investigated using a one way coupling lagrangian particle tracking algorithm.



The second part concerns the study of the flow around moving bodies and the acoustical field generated by it. Based on the flow incompressibility assumption, the problem is decoupled: first the flow solution is computed using Large Eddy Simulation frame work, then the acoustic sources are extracted and finally the acoustical wave propagation is studied using an acoustic analogy developed by Ffowcs-Williams and Hawkings. Three different cases are presented in the papers, all involving rotating bodies: an axial fan, a wind turbine and a propeller. From these



three cases, only the wind turbine computation is presented in more detail in the thesis.



The dynamics of a shock wave in a transonic flow in a channel are investigated in the third part of this thesis using the Large Eddy Simulation framework. Similar phenomena with those encountered in supersonic flows are found: Mach reflection shock wave, regular reflection shock wave, outlet pressure induced hysteresis, unsteady shock wave. (Less)
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author
supervisor
opponent
  • Professor Jens, Soerensen, Department of Energy Engineering, Technical University of Denmark
organization
publishing date
type
Thesis
publication status
published
subject
keywords
vibration and acoustic engineering, Maskinteknik, hydraulics, vacuum technology, Mechanical engineering, plasma, Energy research, Energiforskning, fluiddynamik, plasmas, Gaser, fluid dynamics, Gases, computational fluid dynamics, Acoustic, hydraulik, vakuumteknik, vibrationer, akustik, compressible flow
pages
240 pages
publisher
KFS AB
defense location
Room M:E, M-building, Ole Römers väg 1, Lund Institute of Technology
defense date
2005-12-06 10:15
external identifiers
  • other:ISRN:LUTMDN/TMHP--05/1036--SE
ISSN
0282-1990
ISBN
91-628-6707-5
language
English
LU publication?
yes
id
85f3afd8-ac8a-467a-b150-bbc101cc5ec1 (old id 545748)
date added to LUP
2007-09-10 13:02:30
date last changed
2016-09-19 08:44:58
@phdthesis{85f3afd8-ac8a-467a-b150-bbc101cc5ec1,
  abstract     = {The present thesis mainly focuses on the numerical simulation of the turbulent flow field and acoustics developed in different industrial applications. The study covers a large range of Mach numbers, starting from incompressible regimes and ending with a fully compressible flow.<br/><br>
<br/><br>
In the first part of the thesis, several computations of an incompressible flow, are performed in order to study the behavior of an aircraft engine running close to the ground. The ground vortex interaction and particle ingestion are the investigated topics. The methods involved for solving the flow are the Reynolds Averaged Navier Stokes with a k-epsilon turbulence model closure, Large Eddy Simulation with Smagorinsky sub grid scale model. The particle ingestion problem is investigated using a one way coupling lagrangian particle tracking algorithm.<br/><br>
<br/><br>
The second part concerns the study of the flow around moving bodies and the acoustical field generated by it. Based on the flow incompressibility assumption, the problem is decoupled: first the flow solution is computed using Large Eddy Simulation frame work, then the acoustic sources are extracted and finally the acoustical wave propagation is studied using an acoustic analogy developed by Ffowcs-Williams and Hawkings. Three different cases are presented in the papers, all involving rotating bodies: an axial fan, a wind turbine and a propeller. From these<br/><br>
<br/><br>
three cases, only the wind turbine computation is presented in more detail in the thesis.<br/><br>
<br/><br>
The dynamics of a shock wave in a transonic flow in a channel are investigated in the third part of this thesis using the Large Eddy Simulation framework. Similar phenomena with those encountered in supersonic flows are found: Mach reflection shock wave, regular reflection shock wave, outlet pressure induced hysteresis, unsteady shock wave.},
  author       = {Moroianu, Dragos},
  isbn         = {91-628-6707-5},
  issn         = {0282-1990},
  keyword      = {vibration and acoustic engineering,Maskinteknik,hydraulics,vacuum technology,Mechanical engineering,plasma,Energy research,Energiforskning,fluiddynamik,plasmas,Gaser,fluid dynamics,Gases,computational fluid dynamics,Acoustic,hydraulik,vakuumteknik,vibrationer,akustik,compressible flow},
  language     = {eng},
  pages        = {240},
  publisher    = {KFS AB},
  school       = {Lund University},
  title        = {Numerical Simulations of Turbulent Flows at Widely Different Mach Numbers},
  year         = {2005},
}