Searched for: +
(1 - 19 of 19)
document
Muscari, C. (author), Schito, Paolo (author), Viré, A.C. (author), Zasso, Alberto (author), van Wingerden, J.W. (author)
Actuator line modeling of wind turbines requires the definition of a free-stream velocity in a computational mesh and a regularization kernel to project the computed body forces onto the domain. Both choices strongly influence the results. In this work, a novel velocity sampling method—the so-called effective velocity model (EVM)—is...
journal article 2024
document
Soli, Alessandro (author), Langella, I. (author), Chen, Zhi X. (author)
The physical mechanism leading to flame local extinction remains a key issue to be further understood. An analysis of large eddy simulation (LES) data with presumed probability density function (PDF) based closure (Chen et al., 2020, Combust. Flame, vol. 212, pp. 415) indicated the presence of localised breaks of the flame front along the...
journal article 2021
document
Klapwijk, M.D. (author), Lloyd, T. (author), Vaz, G. (author), van Terwisga, T.J.C. (author)
Different variable resolution turbulence modelling approaches (Hybrid, Bridging models and LES) are evaluated for turbulent channel flow at Re<sub>τ</sub>=395, for cases using either streamwise periodic boundary conditions or a synthetic turbulence generator. The effect of iterative, statistical and discretisation errors is investigated. For...
journal article 2020
document
Böing, S.J. (author)
Deep convective clouds play a key role in tropical weather patterns, summertime rainfall, and the global transport of energy from the tropics to higher latitudes. Current weather and climate models struggle to realistically represent the development and behavior of these clouds. Both the timing of the convection and the role of humidity in the...
doctoral thesis 2014
document
de Wit, L. (author)
conference paper 2010
document
Kenjeres, S. (author)
We conducted a large eddy simulation (LES) of a locally applied electromagnetic control of turbulent thermal convection of an electrically conductive fluid (electrolyte solution) inside of a slender enclosure. Generic configurations, consisting of two or three magnets of opposite polarities located below the lower wall, and two oppositely...
journal article 2009
document
Tessicini, F. (author), Li, N. (author), Leschziner, M.A. (author)
The focus of the paper is on the performance of an approximate 'zonal' near- wall treatment applied within a LES strategy to the simulation of flow separating from a three-dimensional hill at high Reynolds numbers. In the zonal scheme, the state of the near-wall layer of the flow is described by parabolized Navier-Stokes equations solved on a...
conference paper 2006
document
Grinstein, F.F. (author), Fureby, C. (author)
We review our recent progress in understanding the theoretical basis of Implicit Large Eddy Simulation (ILES) and fundamental features relating to its performance. We use the Modified Equation Analysis (MEA) to show that the leading order truncation error terms introduced by a particular class of hybrid methods provide implicit Subgrid Scale ...
conference paper 2006
document
Patnaik, G. (author), Boris, J.P. (author), Grinstein, F.F. (author)
Airborne contaminant transport in cities presents challenging new requirements for CFD. The unsteady flow physics is complicated by very complex geometry, multi-phase particle and droplet effects, radiation, latent, and sensible heating effects, and buoyancy effects. Turbulence is one of the most important of these phenomena and yet the overall...
conference paper 2006
document
Hemida, H. (author), Krajnovic, S. (author)
Large-eddy simulation (LES) is made to investigate the flow around a generic train under side wind conditions. Two different side-wind yaw angles are used in the investigation: 35 and 90 degrees. The Reynolds numbers based on the height of the train and the freestream velocity are 300,000 and 370,000 for the 90 and 35 degrees yaw angles,...
conference paper 2006
document
Davidson, L. (author)
The SAS model (Scale Adapted Simulation) was invented by Menter and co-workers. The idea behind the SST-SAS k-omega model is to add an additional production term -- the SAS term -- in the omega equation, which is sensitive to resolved (i.e. unsteady) fluctuations. When the flow equations resolve turbulence, the length scale based on velocity...
conference paper 2006
document
Thornber, B. (author), Drikakis, D. (author)
This paper derives the implicit model for high-resolution MUSCL reconstruction-based upwind Godunov schemes for turbulent flows. A Mach number expansion of the numerical scheme allows analysis of the theoretical behaviour of the implicit subgrid model as the Mach number becomes small. This shows that different limiting methods within the same...
conference paper 2006
document
Fureby, C. (author)
The present study concerns the application of Large Eddy Simulation (LES) and Implicit LES (ILES) to engineering flow problems. Such applications are often very complicated, involving both complex geometries and complex physics, such as turbulence, chemical reactions, phase changes and compressibility. The aim of the study is to illustrate what...
conference paper 2006
document
Borrel, M. (author), Ryan, J. (author), Billet, G. (author)
A patch adaptive mesh refinement (AMR) platform is presented. Presently two Navier-Stokes solvers are available within this platform : a MUSCL and DG solver (FLUX AMR) and a multi-species MUSCL solver (MAJIC) for reacting flows. The first solver is based on cell centered approaches of finite volume type, the second solver is based on a cell...
conference paper 2006
document
Brandt, T.T. (author)
In large eddy simulations (LES) using low-order finite-difference-type methods, the numerical error can be large in comparison to the effect of the sub-grid scale (SGS) model. In this paper, we study two approaches to explicit filtering which can reduce the numerical error involved. In the first approach, the non-linear convection term of the...
conference paper 2006
document
Panara, D. (author), Porta, M. (author), Schoenfeld, T. (author)
The use of wall functions has been investigated for LES and URANS numerical simulation in pulsating and oscillating channel flow applications. The results show that the wall function approach is accurate in the so-called quasi-steady regime but there are discrepancies with the experimental results in the intermediate frequency range. A special...
conference paper 2006
document
Sternel, D.C. (author), Schäfer, M. (author), Gauss, F. (author), Yigit, S. (author)
Large eddy simulation (LES) becomes more and more important for the simulation of practical turbulent flows. The application for technically relevant, complex configurations leads to systems from around 500,000 up to several million degrees of freedom. For a statistical analysis of the turbulent flow field a large number of time steps have to be...
conference paper 2006
document
Thornber, B. (author), Drikakis, D. (author)
Simulations of three dimensional freely decaying homogeneous turbulence in a periodic cube have been used to examine in a detailed and quantitative manner the behaviour of a Large Eddy Simulation (LES) using implicit subgrid modelling. This paper details the form and behaviour of the implicit subgrid models for the Minmod and third order...
conference paper 2006
document
Hadziabdic, M. (author)
This thesis reports on a numerical study of a round, isothermal turbulent jet of incompressible fluid, impinging normally on a flat wall at a different temperature. The aim was to generate detailed information about the ime-dependent three-dimensional velocity and temperature field, and, based on this, to extract statistically averaged flow and...
doctoral thesis 2006
Searched for: +
(1 - 19 of 19)