Sökning: "large-eddy simulation LES"

Visar resultat 21 - 25 av 127 avhandlingar innehållade orden large-eddy simulation LES.

1. 21. Development of a Multidimensional Residual Distribution Solver for Large Eddy Simulation of Industrial Turbulent Flows

   Författare :Doru Caraeni; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Thermal engineering; High-Order Compact Schemes.; Compressible Flows; Parallel Computations; Multidimensional Residual Distribution Schemes; Large Eddy Simulation; applied thermodynamics; Termisk teknik; termodynamik;

   Sammanfattning : This thesis presents the results of the author's research activity to develop a time-space accurate flow-solver for Large Eddy Simulations (LES), based on the Multidimensional Residual Distribution approach. The aim of this work is the attempt to develop a compact high-order algorithm which includes multidimensional flow physics, in hope of creating a better algorithm for LES of turbulent compressible flows. LÄS MER

3. 22. Anisotropy-resolving subgrid-scale modelling using explicit algebraic closures for large eddy simulation

   Författare :Amin Rasam; Arne Johansson; Bernard Geurts; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulence; large eddy simulation; explicit algebraic subgridscale model; passive scalar; stochastic modelling; periodic hill flow; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : The present thesis deals with the development and performance analysis ofanisotropy-resolving models for the small, unresolved scales (”sub-grid scales”,SGS) in large eddy simulation (LES). The models are characterised by a descriptionof anisotropy by use of explicit algebraic models for both the subgridscale(SGS) stress tensor (EASSM) and SGS scalar flux vector (EASSFM). LÄS MER

4. 23. Numerical and modelling aspects of large-eddy and hybrid simulations of turbulent flows

   Författare :Matteo Montecchia; Arne V. Johansson; Gert Brethouwer; Stefan Wallin; Dominic Von Terzi; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbulence; wall-bounded flows; large-eddy simulation; SGS modelling; OpenFOAM; hybrid RANS-LES; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : In this study, the explicit algebraic sub-grid scale (SGS) model (EAM) has been extensively validated in wall-resolved large-eddy simulations (LES) of wall-bounded turbulent flows at different Reynolds numbers and a wide range of resolutions. Compared to eddy-viscosity based models, the formulation of the EAM is more consistent with the physics and allows to accurately capture SGS anisotropy,which is relevant especially close to walls. LÄS MER

5. 24. Approaching Large Eddy Simulation of Cavitating Flows for Marine Applications

   Författare :Niklas Wikström; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VOF; OpenFOAM; CFD; LES; Navier-Stokes; incompressible free surface flow; Cavitation;

   Sammanfattning : Cavitation is a major concern in naval craft design as well as in the shipping industry. Although the nature of cavitation is not fully understood, propellerdesigns are presently improved by experimental analysis of the phenomena. LÄS MER

7. 25. 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