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van Nooijen, R.R.P. (author), Kolechkina, A.G. (author)In almost all practical applications of control, technological and economical consid -erations impose limits on communication speed, frequency of communication, and frequency of actuator adjustment. Such limits turned the analysis of sampled data systems into a flourishing field. Water systems pose a particular challenge: the systems are...journal article 2021
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Ouro, Pablo (author), Juez, Carmelo (author), Franca, M.J. (author)Large-Eddy Simulations (LES) are used to investigate the governing processes involved in mass and momentum transfer between the flow in the main channel and symmetrically-distributed lateral bank cavities. In-cavity free-surface velocities, based on laboratory measurements made in an open channel, are used to validate the numerical results. A...journal article 2020
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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
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Zhao, Xuanyu (author), Bolognin, M. (author), Donfang, Lian (author), Rohe, A. (author), Vardon, P.J. (author)This paper describes the development and application of inflow and outflow boundary conditions (BCs) for the material point method (MPM) in order to simulate fluid flow problems. This corresponds to velocity and pressure controlled BCs. Due to the coupled Lagrangian and Eulerian description of the fluid motion in MPM it is necessary to add and...journal article 2019
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Klapwijk, M.D. (author), Lloyd, Thomas (author), Vaz, Guilherme (author), van Terwisga, T.J.C. (author)<br/>conference paper 2019
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Klapwijk, M.D. (author), Lloyd, T. (author), Vaz, G. (author)Partially Averaged Navier–Stokes computations can employ three different approaches for specifying the ratio of modelled-to-total turbulence kinetic energy f<sub>k</sub>. Use can be made of either a constant, a spatially- or a spatially- and temporally-varying value. This work compares different estimates for f<sub>k</sub> found in literature...journal article 2019
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Silvestri, S. (author), Patel, A. (author), Roekaerts, D.J.E.M. (author), Pecnik, Rene (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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Goudar Vishwanathappa, M. (author), Breugem, W.P. (author), Elsinga, G.E. (author)For channel flow, we explore how commonly found weak eddies can still auto-generate and produce new eddies. Before, only strong eddies (above a threshold strength) were considered to auto-generate. Such strong eddies are rarely observed in actual turbulent flows however. Here, the evolution of two weak conditional eddies with different initial...journal article 2016
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Ebrahimi, Amin (author), Naranjani, Benyamin (author)In this study, a flat-plate channel configured with pyramidal protrusions are numerically analysed for the first time. Simulations of laminar single-phase fluid flow and heat transfer characteristics are developed using a finite-volume approach under steady-state condition. Pure water is selected as the coolant and its thermo-physical...journal article 2016
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Burchard, H. (author), Schuttelaars, H.M. (author), Rockwell Geyer, W. (author)In this idealized numerical modeling study, the composition of residual sediment fluxes in energetic (e.g., weakly or periodically stratified) tidal estuaries is investigated by means of one-dimensional water column models, with some focus on the sediment availability. Scaling of the underlying dynamic equations shows dependence of the results...journal article 2013
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Xu, M. (author)Fresh water supply and flood protection are two central issues in water management. Society needs more and more fresh water and a safe water system to guarantee a better life. A more severe climate will result in more droughts and extreme storms. As a consequence, salt water intrusion will increase. Therefore, clean and fresh water is becoming...doctoral thesis 2013
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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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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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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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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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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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Zeng, J. (author), Constantinescu, G. (author), Blanckaert, K. (author), Weber, L. (author)This paper focuses on experiments and simulations conducted in very sharp open-channel bends with flat and equilibrium bathymetry, corresponding to the initial and final phases of the erosion and deposition processes, respectively. The study of flow in curved open bends is relevant for flow in natural river configurations, as most river reaches...journal article 2008
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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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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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Akkerman, I. (author), Bazilevs, Y. (author), Calo, V.M. (author), Hughes, T.J.R. (author), Hulshoff, S. (author)This paper examines the role of continuity of the basis in the computation of turbulent flows. We compare standard finite elements and non-uniform rational B-splines (NURBS) discretizations that are employed in Isogeometric Analysis (Hughes et al. in Comput Methods Appl Mech Eng, 194:4135–4195, 2005). We make use of quadratic discretizations...journal article 2007
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