Searched for: department%3A%22Hydraulic%255C%252BEngineering%22
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Radermacher, M. (author), De Wit, L. (author), Uijttewaal, W.S.J. (author), Winterwerp, J.C. (author)
When dredging in sensitive environments, efforts have to be made to limit the free dispersal of suspended fine sediment from the dredging spill. Especially the use of hanging silt curtains as an environmental mitigation measure is widespread. Despite frequent application, their ability to reduce turbidity levels through vertical diversion of...
journal article 2015
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Zijlema, M. (author)
This paper presents the application of the open source non-hydrostatic wave-flow model SWASH to propagation of irregular waves in a barred surf zone, and the model results are discussed by comparing against an extensive laboratory data set. This study focus not only on wave transformation in the surf zone, but also on the numerical prediction of...
conference paper 2014
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Winterwerp, J.C. (author), Van Kesteren, W.G.M. (author), Van Prooijen, B.C. (author), Jacobs, W. (author)
This paper proposes a conceptual framework for erosion of cohesive sediment beds. We focus on cohesive beds, distinguishing between floc erosion, surface erosion, and mass erosion. By (our) definition, surface erosion is a drained soil mechanical process, whereas mass erosion occurs under undrained conditions. The eroding shear stress is modeled...
journal article 2012
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Dijkstra, J.T. (author)
Aquatic plants –or macrophytes- are an important part of coastal, estuarine and freshwater ecosystems worldwide, both from an ecological and an engineering viewpoint. Their meadows provide a wide range of ecosystem services: forming a physical protection of the shoreline, enhancing water quality and harbouring many other organisms. Unfortunately...
doctoral thesis 2012
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Breugem, W.A. (author)
Two experiments are performed in order to investigate suspended sediment transport in a turbulent open channel flow. The first experiment used particle image velocimetry (PIV) to measure the fluid velocity with a high spatial resolution, while particle tracking velocimetry (PTV) was used to measure the velocity of individual sediment particles....
doctoral thesis 2012
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Dijkstra, J.T. (author), Uittenbogaard, R.E. (author)
Aquatic vegetation has an important role in estuaries and rivers by acting as bed stabilizer, filter, food source and nursing area. However, macrophyte populations worldwide are under high anthropogenic pressure. Protection and restoration efforts will benefit from more insight into the interaction between vegetation, currents, waves and...
journal article 2010
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Sukhodolov, A.N. (author), Schnauder, I. (author), Uijttewaal, W.S.J. (author)
Shallow lateral shear layers forming between flows with different velocities, though essential for mixing processes in natural streams, have been examined only in laboratory settings using smooth, fixed?bed channels. This paper reports the results of an experimental study of a shear layer in a straight reach of a natural river where the layer,...
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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Hoan, N.T. (author), Booij, R. (author), Hofland, B. (author), Stive, M.J.F. (author), Verhagen, H.J. (author)
The current research is aimed at finding a proper relation between flow forces acting on the bed and the bed response. To this end, experiments were carried out in which both the bed response (quantified by a dimensionless entrainment rate) and the flow field (velocity and turbulence intensity distributions) are measured. The three available...
conference paper 2007
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Hoan, N.T. (author), Booij, R. (author), Hofland, B. (author), Stive, M.J.F. (author), Verhagen, H.J. (author)
The current research is aimed at finding a dimensionless stability parameter for non-uniform flow in which the effect of turbulence is incorporated. To this end, experiments were carried out in which both the bed response (quantified by a dimensionless entrainment rate) and the flow field (velocity and turbulence intensity distributions) are...
conference paper 2007
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Dijkstra, J.T. (author), Uittenbogaard, R.E. (author), Stive, M.J.F. (author)
In many areas around the world, there is a large interest in the protection and restoration of aquatic vegetation, like eelgrass (Zostera marina), but little is known about the interaction of such vegetation with its environment. To improve this knowledge, a model has been developed that simulates this interaction between highly flexible...
conference paper 2006
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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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Kranenburg, C. (author)
The Prandtl mixing-length model of turbulent exchange of mass and momentum is applied to calculate the entrainment of overlying water into a layer of suspended fine sediment at a horizontal bed. In the field the flow and turbulence in such a concentrated benthic suspension (CBS) are driven by a streamwise pressure gradient resulting from the...
report 1999
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Suastika, I.K. (author)
In this report we present some results of a laboratory pilot study which has been conducted to test a method to artificially enhance the turbulence of a water flow in a laboratory flume. The purpose of this test is to provide data which will be used to verify whether the method is suitable for the study of the dissipative effects of turbulence...
report 1998
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Bijvelds, M.D.J.P. (author)
In this report the water flow in harbours, that are situated on a river, are considered. Due to the flow velocity difference between the river and the harbour, a turbulent mixing layer develops at the harbour entrance. The shallowness of the water induces the coexistance of two disparate turbulent length scales in these regions. Besides the ...
report 1997
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Hoffmans, G.J.C.M. (author)
The general purpose of this research project is to model mathematically the scour-hole downstream of a structure (2-D). The model has to simulate the development of the scour as a function of time. Basically two models are necessary namely a flow model and a morphological model. The latter has to describe the bed- and suspended load and the...
report 1988
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Kranenburg, C. (author)
A k-model is formulated that consists of the turbulent kinetic energy equation and an algebraic expression for the mixing length taking into account the influence of stratification. Applicability of the model is restricted to shallow, nearly horizontal flows. For local-equilibrium flows the model reduces to the well-known mixing-length...
report 1985
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Booij, R. (author)
For the prediction of dispersion phenomena and of changes in the morphology of an alluvial bottom, a detailed description of the water flow is necessary. The flow in estuaries is a complicated one, partly because of the time-dependence. To isolate this aspect of tidal flow a simplifying one-dimensional (vertical) flow model 1S used. This one...
report 1982
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Koppel, T. (author)
Experiments on unsteady separating flow past a sudden expansion in an open channel are described. To simulate tidal flow the flow rate in the approach channel varied as a half-sine with time. Different visualization techniques to obtain an insight into the behaviour of the separating vortex in time and space were used. Laser-Doppler velocimetry ...
report 1981
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De Vriend, H.J. (author)
After the study of fully developed and developing steady laminar flow in curved channels of shallow rectangular wet cross-section (see earlier reports in this series), steady turbulent flow in such channels is investigated as a next step towards a mathematical model of the flow in shallow river bends. A mathematical model is developed for this...
report 1979
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