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Mulder, G. (author), van Leijen, F.J. (author), Hanssen, R.F. (author)
The observed phase in time series of interferometric synthetic aperture radar (InSAR) products is a superposition of various components. Differential topography, line-of-sight displacements, and differential atmospheric delays are the main contributions and need to be disentangled to derive accurate digital elevation model (DEM), deformation,...
journal article 2023
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Wani, F.M. (author), Shipurkar, U. (author), Dong, J. (author), Polinder, H. (author)
This paper compares active and passive cooling systems in tidal turbine power electronic converters. The comparison is based on the lifetime of the IGBT (insulated gate bipolar transistor) power modules, calculated from the accumulated fatigue due to thermal cycling. The lifetime analysis accounts for the influence of site conditions, namely...
journal article 2021
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Abelmann, Leon (author), Hageman, Tijmen (author), Löthman, Per (author), Mastrangeli, Massimo (author), Elwenspoek, Miko (author)
Interaction between dipolar forces, such as permanent magnets, generally leads to the formation of one-dimensional chains and rings. We investigated whether it was possible to let dipoles self-assemble into three-dimensional structures by encapsulating them in a shell with a specific shape. We found that the condition for self-assembly of a...
journal article 2020
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Löthman, Per A. (author), Hageman, Tijmen A.G. (author), Elwenspoek, Miko C. (author), Krijnen, Gijs J.M. (author), Mastrangeli, Massimo (author), Manz, Andreas (author), Abelmann, Leon (author)
The extent to which one can use a thermodynamic description of turbulent flow as a source of stochastic kinetic energy for 3D self‐assembly of magnetically interacting macroscopic particles is investigated. It is confirmed that the speed of the objects in the flow field generated in this system obeys the Maxwell–Boltzmann distribution, and their...
journal article 2020
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Prades, Lledó (author), Fabbri, Stefania (author), Dorado, Antonio D. (author), Gamisans, Xavier (author), Stoodley, Paul (author), Picioreanu, C. (author)
Experimental data showed that high-speed microsprays can effectively disrupt biofilms on their support substratum, producing a variety of dynamic reactions such as elongation, displacement, ripple formation, and fluidization. However, the mechanics underlying the impact of high-speed turbulent flows on biofilm structure is complex under such...
journal article 2020
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van Emmerik, T.H.M. (author), Steele-Dunne, S.C. (author), Guerin, Marceau (author), Gentine, Pierre (author), Oliveira, Rafael (author), Hut, R.W. (author), Selker, John (author), Wagner, Jim (author), van de Giesen, N.C. (author)
journal article 2018
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van Hout, R.L.H. (author), Eisma, H.E. (author), Elsinga, G.E. (author), Westerweel, J. (author)
In many applications, finite-sized particles are immersed in a turbulent boundary layer (TBL) and it is of interest to study wall effects on the instantaneous shedding of turbulence structures and associated mean velocity and Reynolds stress distributions. Here, 3D flow field dynamics in the wake of a prototypical, small sphere (D+=50, 692&lt...
journal article 2018
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van Emmerik, T.H.M. (author), Steele-Dunne, S.C. (author), Hut, R.W. (author), Gentine, Pierre (author), Guerin, Marceau (author), Oliveira, Rafael (author), Wagner, Jim (author), Selker, John (author), van de Giesen, N.C. (author)
Trees play a crucial role in the water, carbon and nitrogen cycle on local, regional and global scales. Understanding the exchange of momentum, heat, water, and CO 2 between trees and the atmosphere is important to assess the impact of drought, deforestation and climate change. Unfortunately, ground measurements of tree properties such as mass...
journal article 2017
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van den Engel, P.J.W. (author), Kurvers, S.R. (author)
An overview is given of recent developments in the use of a system of inducing natural air supply via the façade in the Netherlands. This is followed by a review of the results of measurements from climate chamber experiments of its inducing ventilation performance and detailed insights gained from related experiments of climate chamber...
journal article 2017
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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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Tomas, J.M. (author), Pourquie, M.J.B.M. (author), Jonker, H.J.J. (author)
Predicting pollutant dispersion in urban environments requires accurate treatment of obstacle geometry, inflow turbulence and temperature differences. This paper considers both the influence of thermal stratification and the presence of a single obstacle on pollutant dispersion in turbulent boundary layers (TBLs). Turbulent flow over a fence...
journal article 2015
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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
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Ambesi, D. (author), Kleijn, C.R. (author), Den Hartog, E.A. (author), Bouma, R.H.B. (author), Brasser, P. (author)
In chemical, biological, radiological, and nuclear protective clothing, a layer of activated carbon material in between two textile layers provides protection against hazardous gases. A cylinder in cross flow, sheathed by such material, is generally used to experimentally test the garment properties. This is, however, complicated and predictive...
journal article 2013
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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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Violato, D. (author), Scarano, F. (author)
The three-dimensional behavior of jet core breakdown is investigated with experiments conducted on a free water jet at Re = 5000 by time-resolved tomographic particle image velocimetry (TR-TOMO PIV). The investigated domain encompasses the range between 0 and 10 jet diameters. The characteristic pulsatile motion of vortex ring shedding and...
journal article 2013
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Lay-Ekuakille, A. (author), Palamara, I. (author), Caratelli, D. (author), Morabito, F.C. (author)
Subterranean waters are often polluted by industrial and anthropic effluents that are drained in subsoil. To prevent and control pollution, legislations of different developed countries require an online monitoring measurement, especially for detecting organic solvents (chlorinated and unchlorinated ones). Online measurements include both real...
journal article 2013
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Eckhardt, B.E. (author)
The study of the transition to turbulence in parallel shear flows without linear instability of the laminar profile has profited immensely from the application of dynamical systems ideas. Studies of the transition in plane Couette flow and pipe flow, in particular, have shown that the transition is connected with the appearance of 3-d coherent...
journal article 2012
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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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Trip, R. (author), Kuik, D.J. (author), Westerweel, J. (author), Poelma, C. (author)
The transitional regime of a sinusoidal pulsatile flow in a straight, rigid pipe is investigated using particle image velocimetry. The main aim is to investigate how the critical Reynolds number is affected by different pulsatile conditions, expressed as the Womersley number and the oscillatory Reynolds number. The transition occurs in the...
journal article 2012
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Violato, D. (author), Scarano, F. (author)
The three-dimensional behavior of flow transition in circular and 6-chevron jets at Re?=?5000 is investigated with experiments conducted on a free water jet by time-resolved tomographic particle image velocimetry. The emphasis is on the unsteady organization of coherent flow structures, which play a role in the generation of acoustic noise....
journal article 2011
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