Sökning: "large eddy simulation LES"

Visar resultat 21 - 25 av 128 avhandlingar innehållade orden large eddy simulation LES.

1. 21. Computational Aeroacoustics Based on Large Eddy Simulation and Acoustic Analogies

   Författare :Mihai Mihaescu; Laszlo Fuchs; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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; Computational Aeroacoustics;

   Sammanfattning : 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. LÄS MER

3. 22. Transonic flow: large eddy simulation, numerical methods and subgrid modeling

   Författare :Christian Wollblad; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LES; SGS modeling; Transonic flow; semi-implicit numerical scheme; shock wave turbulent boundary layer interaction;

   Sammanfattning : Shock wave turbulent boundary layer interactions (SWTBLI) commonly arise in turbomachinery and aerospace applications and on the exterior of high speed aircrafts. In all these cases, SWTBLI can significantly change the flow and hence the physical load imposed by it. LÄS MER

4. 23. Large Eddy Simulation of Turbulent Swirling Flows in Combustor Related Geometries

   Författare :Yajing Wu; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Swirling flow; swirler; vortex breakdown; precessing vortex core PVC ; large eddy simulation LES .;

   Sammanfattning : This thesis deals with the physics of turbulent swirling flows. Large eddy simulation (LES) method is used to investigate the vortex breakdown process, the precessing vortex core (PVC), and the effect of swirl number and flow field configuration on swirling flows. The study is based on an open source CFD code, \textit{OpenFoam}. LÄS MER

5. 24. Large Eddy Simulation of Turbulent Flow and Combustion in HCCI Engines

   Författare :Rixin Yu; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulent combustion; Numerical methods.; LES; Temperature inhomogeneity; HCCI combustion; In-cylinder flow;

   Sammanfattning : This thesis deals with numerical simulations of the turbulent combustion process in Homogeneous Charge Compression Ignition (HCCI) engines. An accurate and computationally efficient Large Eddy Simulation (LES) model was developed and used throughout this thesis to investigate the development of in-cylinder turbulence, temperature stratification, onset of auto-ignition, and development of the reaction fronts. LÄS MER

7. 25. Modelling Techniques for Large-Eddy Simulation of Wall-Bounded Turbulent Flows

   Författare :Timofey Mukha; Mattias Liefvendahl; Hrvoje Jasak; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Wall modelling; Inflow generation; Large-eddy simulation; OpenFOAM; Computational fluid dynamics; Scientific Computing; Beräkningsvetenskap;

   Sammanfattning : Large-eddy simulation (LES) is a highly accurate turbulence modelling approach in which a wide range of spatial and temporal scales of the flow are resolved. However, LES becomes prohibitively computationally expensive when applied to wall-bounded flows at high Reynolds numbers, which are typical of many industrial applications. LÄS MER