Searched for: subject%3A%22simulation%22
(1 - 20 of 25)

Pages

document
Tosto, F. (author), Wheeler, Andrew (author), Pini, M. (author)
In this work, we investigate the sources of dissipation in adiabatic boundary layers of non-ideal compressible fluid flows. Direct numerical simulations of transitional, zero-pressure gradient boundary layers are performed with an in-house solver considering two fluids characterized by different complexity of the fluid molecules, namely air...
book chapter 2023
document
Blishchik, A. (author)
Steel is found irreplaceable in many industrial applications. It is currently predicted that steel consumption will increase significantly in the coming decades. Humanity is expected to produce more and more steel-based products, such as cables, cars, railways, bridges, stadiums, skyscrapers, etc. The increased demand will pose a serious...
doctoral thesis 2022
document
Klapwijk, M.D. (author)
There is increasing attention for the effects of anthropogenic underwater radiated noise (URN) on marine fauna. This is expected to lead to regulations with respect to the maximum permitted sound emissions of ships. It is known that cavitating tip vortices, generated by ship propellers, are some of the key contributors to URN. Consequently,...
doctoral thesis 2021
document
Schoenmaker, Lars (author)
In this thesis diffuser performance will be simulated with computational fluid dynamics, which will be done with the program Ansys Fluent. The expanding geometry creates an adverse pressure gradient and under certain conditions there will also be separation.<br/><br/>At first a relative simple simulation will be done of a one-directional...
master thesis 2017
document
Van der Dussen, J.J. (author)
Clouds have a strong net cooling effect on our planet, as they reflect a large part of the incident solar radiation. To be able to make accurate forecasts of the global climate, cloudiness should therefore be correctly represented by climate models. Currently, however there are large differences in the forecasted temperature increase among...
doctoral thesis 2015
document
Boersma, B.J. (author), Pecnik, R. (author), Nemati, H. (author), Peeters, J.W.R. (author)
In this paper we discuss the effect of sharp property variations on the turbulent heat transfer in fluids close the critical point. The governing equations for this flow regime are discussed, a short description of the numerical tools that have been developed to study these flows is given. Finally, some results for supercritical heat transfer in...
journal article 2015
document
Sun, Z. (author)
The micro vortex generator (MVG) is used extensively in low speed aerodynamic problems and is now extended into the supersonic flow regime to solve undesired flow features that are associated with shock wave boundary layer interactions (SWBLI) such as flow separation and associated unsteadiness of the interaction system. Numerous experimental...
doctoral thesis 2014
document
Kenjeres, S. (author)
Motivated by the concept of interdependency of turbulent flow and electromagnetic fields inside the spiraling galaxies, we explored the possibilities of generating a localized Lorentz force that will produce a three-dimensional swirling flow in weakly conductive fluids. Multiple vortical flow patterns were generated by combining arrays of...
journal article 2011
document
Van Balen, W. (author), Uijttewaal, W.S.J. (author), Blanckaert, K. (author)
Large-eddy simulation (LES) is performed of a curved open-channel flow over topography based on the laboratory experiment by Blanckaert [“Topographic steering, flow circulation, velocity redistribution and bed topography in sharp meander bends,” Water Resour. Res., doi:10.1029/2009WR008303 (in press)] . In the experiment, the large-scale bed...
journal article 2010
document
Van Balen, W. (author)
The flow of water through a river bend can be characterized as a turbulent open-channel flow that is dominated by streamline curvature. In order to adequately manage the planimetry of meandering rivers and the according safety aspects, the features of the flow and the associated turbulence have to be understood well. This thesis presents results...
doctoral thesis 2010
document
Bijlard, M.J. (author)
doctoral thesis 2009
document
Gillissen, J.J.J. (author), Boersma, B.J. (author), Mortensen, P.H. (author), Andersson, H.I. (author)
Turbulent fiber suspension channel flow is studied using direct numerical simulation. The effect of the fibers on the fluid mechanics is governed by a stress tensor, involving the distribution of fiber position and orientation. Properties of this function in channel flow are studied by computing the trajectories and orientations of individual...
journal article 2007
document
van Reeuwijk, M. (author)
This dissertation focuses on turbulent thermal convection, which occurs in a wide range of geophysical and engineering situations, such as the atmosphere, the sun, the earth's mantle, indoor climates etc. The first part of the thesis comprises a fundamental study of Rayleigh-BÉnard convection in a domain with aspect-ratio four. An ensemble of...
doctoral thesis 2007
document
Gillissen, J.J.J. (author), Boersma, B.J. (author), Mortensen, P.H. (author), Andersson, H.I. (author)
Fiber-induced drag reduction can be studied in great detail by means of direct numerical simulation [ J. S. Paschkewitz et al., J. Fluid Mech. 518, 281 (2004) ]. To account for the effect of the fibers, the Navier-Stokes equations are supplemented by the fiber stress tensor, which depends on the distribution function of fiber orientation angles....
journal article 2007
document
Geurts, B.J. (author)
We analyze the evolution of a diffusion flame in a turbulent mixing layer using large-eddy simulation. The large-eddy simulation includes Leray regularization of the convective transport and approximate inverse filtering to represent the chemical source terms. The Leray model is compared to the more conventional dynamic mixed model. The location...
conference paper 2006
document
Campagne, G. (author), Cazalbou, J.B. (author), Joly, L. (author), Chassaing, P. (author)
In this paper, direct numerical simulation is used to study the interaction between turbulence and a free surface. The configuration is original due to the fact that a random force generates turbulence in the vicinity of a plane parallel to the free surface. Turbulence is therefore statistically steady and nearly isotropic at some distance of...
conference paper 2006
document
Guermond, J.L. (author), Prudhomme, S. (author)
The purpose of this paper is to show that the Fourier-based Nonlinear Galerkin Method (NLGM) constructs suitable weak solutions to the periodic Navier--Stokes equations in three dimensions. We re-interpret NLGM as a Large-Eddy Simulation technique (LES) and we rigorously deduce a relationship between the mesh size and the large-eddy scale.
conference paper 2006
document
Meyers, J. (author), Sagaut, P. (author)
A theoretical analysis is presented on the dependence of the standard and variational multi-scale Smagorinsky models on the proximity of the LES filter width Delta to the integral length scale of turbulence L on the one hand, and to the Kolmogorov scale eta on the other hand. Moreover modifications of the models are formulated, which respond...
conference paper 2006
document
Geurts, B.J. (author)
Non-uniform filtering of the Navier-Stokes equations expresses itself, next to the turbulent stresses, in additional closure terms known as commutator errors. These terms require explicit subgrid modeling if the non-uniformity of the filter is sufficiently pronounced. We derive expressions for the magnitude of the mean flux, the turbulent stress...
conference paper 2006
document
Hughes, T.J.R. (author), Wells, G.N. (author), Wray, A.A. (author)
Energy transfers within large-eddy simulation (LES) and direct numerical simulation (DNS) grids are studied. The spectral eddy viscosity for conventional dynamic Smagorinsky and variational multiscale LES methods are compared with DNS results. Both models underestimate the DNS results for a very coarse LES, but the dynamic Smagorinsky model is...
journal article 2004
Searched for: subject%3A%22simulation%22
(1 - 20 of 25)

Pages