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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
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Zhao, L.H. (author), Andersson, H.I. (author), Gillissen, J.J.J. (author)
This letter reports on the pronounced turbulence modulations and the accompanying drag reduction observed in a two-way coupled simulation of particle-laden channel flow. The present results support the view that drag reduction can be achieved not only by means of polymeric or fiber additives but also with spherical particles.
journal article 2010
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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
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Manceau, R. (author), Hanjali?, K. (author)
A new approach to modeling the effects of a solid wall in one-point second-moment (Reynolds-stress) turbulence closures is presented. The model is based on the relaxation of an inhomogeneous (near-wall) formulation of the pressure–strain tensor towards the chosen conventional homogeneous (far-from-a-wall) form using the blending function ?, for...
journal article 2001
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Blanckaert, K. (author), De Vriend, H.J. (author)
In spite of its importance, little is known about the turbulence characteristics in open-channel bends. This paper reports on an experimental investigation of turbulence in one cross section of an open-channel bend. Typical flow features are a bicellular pattern of cross-stream circulation (secondary flow) and a turbulence activity in the outer...
journal article 2005
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Silvestri, S. (author), Patel, A. (author), Roekaerts, D.J.E.M. (author), Pecnik, R. (author)
The present work consists of an investigation of the turbulence radiation interaction (TRI) in a radiative turbulent channel flow of grey gas bounded by isothermal hot and cold walls. The optical thickness of the channel is varied from 0.1 to 10 to observe different regimes of TRI. A high-resolution finite volume method for radiative heat...
journal article 2018
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Breugem, W.P. (author), Boersma, B.J. (author)
A direct numerical simulation (DNS) has been performed of turbulent channel flow over a three-dimensional Cartesian grid of 30×20×9 cubes in, respectively, the streamwise, spanwise, and wall-normal direction. The grid of cubes mimics a permeable wall with a porosity of 0.875. The flow field is resolved with 600×400×400 mesh points. To enforce...
journal article 2005
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Cortis, A. (author), Smeulders, D.M.J. (author), Guermond, J.L. (author), Lafarge, D. (author)
The high-frequency behavior of the fluid velocity patterns for smooth and corrugated pore channels is studied. The classical approach of Johnson et al. [J. Fluid Mech. 176, 379 (1987)] for smooth geometries is obtained in different manners, thus clarifying differences with Sheng and Zhou [Phys. Rev. Lett. 61, 1591 (1988)] and Avellaneda and...
journal article 2003
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Gillissen, J.J.J. (author)
Polymer-induced drag reduction is the phenomenon by which the friction factor of a turbulent flow is reduced by the addition of small amounts of high-molecular-weight linear polymers, which conformation in solution at rest can vary between randomly coiled and rodlike. It is well known that drag reduction is positively correlated to viscous...
journal article 2008
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Van Prooijen, B.C. (author), Uijttewaal, W.S.J. (author)
The development of large coherent structures in a shallow mixing layer is analyzed. The results are validated with experimental data obtained from particle tracking velocimetry. The mean flow field is modeled using the self-similarity of the velocity profiles. The characteristic features of the down-stream development of a shallow mixing layer...
journal article 2002
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Li, Y. (author), McLaughlin, J.B. (author), Kontomaris, K. (author), Portela, L. (author)
This paper presents results for the behavior of particle-laden gases in a small Reynolds number vertical channel down flow. Results will be presented for the effects of particle feedback on the gas-phase turbulence and for the concentration profile of the particles. The effects of density ratio, mass loading, and particle inertia will be...
journal article 2001
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Kenjeres, S. (author)
Numerical simulations and analysis of flow and heat transfer of an electrically conducting fluid past magnetic obstacles are reported. We studied the channel flow configuration with electrically and thermally insulated horizontal walls containing a single or multiple (two or three) magnetic dipoles. Different values of the interactive parameter...
journal article 2012
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Mortensen, P.H. (author), Andersson, H.I. (author), Gillissen, J.J.J. (author), Boersma, B.J. (author)
The translational and rotational motions of small spherical particles dilutely suspended in a turbulent channel flow have been investigated. Three different particle classes were studied in an Eulerian-Lagrangian framework to examine the effect of the response times on the particle statistics. The results for the fluctuating particle velocities...
journal article 2007
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Kenjereš, S. (author), Hanjali?, K. (author), Bal, D. (author)
A magnetic field, imposed on turbulent flow of an electrically conductive fluid, is known to cause preferential damping of the velocity and its fluctuations in the direction of Lorentz force, thus leading to an increase in stress anisotropy. Based on direct numerical simulations (DNS), we have developed a model of magnetohydrodynamic (MHD)...
journal article 2004
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Mortensen, P.H. (author), Andersson, H.I. (author), Gillissen, J.J.J. (author), Boersma, B.J. (author)
The dynamical behavior of tiny elongated particles in a directly simulated turbulent flow field is investigated. The ellipsoidal particles are affected both by inertia and hydrodynamic forces and torques. The time evolution of the particle orientation and translational and rotational motions in a statistically steady channel flow is obtained for...
journal article 2008
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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
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Holmen, J. (author), Hughes, T.J.R. (author), Oberai, A.A. (author), Wells, G.N. (author)
The variational multiscale method has been shown to perform well for large-eddy simulation (LES) of turbulent flows. The method relies upon a partition of the resolved velocity field into large- and small-scale components. The subgrid model then acts only on the small scales of motion, unlike conventional LES models which act on all scales of...
journal article 2004
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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
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Hazari, S.A. (author)
Stratified two phase flow is one of the flow regimes that is of importance in multiphase flow transport through pipelines, such as used for example in the oil and gas industry. Its application also extends to chemical production, energy conversion and food processing. The phenomenon of turbulence further complicates the stratified flow behaviour...
master thesis 2016
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van der Vooren, J. (author), Sanderse, A. (author)
A fully-conservative- finite difference algorithm is described to calculate the incompressible flow through a straight channel of varying rectangular cross section. Both the width and the height of the channel may vary independently. The algorithm has been used successfully in the design of the German-Dutch low speed wind tionel (DNW).
report 1977
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