Searched for: contributor:"Westerweel, J. (promotor)"
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Jahangir, S. (author)
Cavitation is a well-known phenomenon, occurring in a wide range of applications. In most applications, cavitation is undesirable, such as turbines, pumps, ship propellers and diesel injector nozzles. Cavitation can cause material erosion, flow blockage, noise and degradation of equipment over time. The ability to predict the behavior of this...
doctoral thesis 2020
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Gül, M. (author)
This thesis aims to contribute to the physical understanding of turbulence in canonical flows. For that purpose, experiments are conducted in a statistically steady turbulent pipe flow, ramp-type accelerating/decelerating turbulent pipe flow and turbulent Taylor-Couette flow. For the first two flows, time-resolved data is acquired in the cross...
doctoral thesis 2019
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van Eckeveld, A.C. (author)
Flow-induced acoustics are a well-known phenomenon, occurring in a broad variety of applications, as well as in nature. In many applications, the produced acoustics are purposeful, e.g. for communication and in musical instruments. In other circumstances, however, the sound and vibrations are a nuisance, and even harmful to human beings and the...
doctoral thesis 2019
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Benschop, H.O.G. (author)
A significant part of the fuel used for transportation results from the drag in turbulent flows. Techniques for turbulent drag reduction yield associated reductions of the fuel consumption and greenhouse gas emissions, which is desirable from both economic and environmental perspectives (cf. chapter 1). This thesis investigates two passive...
doctoral thesis 2018
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Quaranta, G. (author)
Synchronization of oscillators is an ubiquitous phenomenon that involves mechanical systems, like pendulum clocks, but also biological systems, like peacemaker cells in the heart or neural activity in the brain. If we consider biological systems at the microscale, namely at the scale of cells, we find that processes like locomotion and fluid...
doctoral thesis 2018
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Valori, V. (author)
Fluids above the critical point are widely used in industry. Chemical, pharmaceutical, food industry and energy production are some examples. In the energy production sector they are mainly used as cooling fluids, because they allow to increase the thermal efficiency of the power plants. However, the fundamentals of their heat transfer behavior...
doctoral thesis 2018
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Simões Costa, P. (author)
Transport of particles by a carrier fluid is an important, ubiquitous process. Few of many obvious examples are the blood flow that feeds oxygen to the different parts of our bodies, wind-assisted pollination, sediment transport in sand storms, avalanches, or rivers, cloud formation, and pyroclastic flows. In industry one can think of the...
doctoral thesis 2017
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Goudar Vishwanathappa, M. (author)
Turbulence is implicitly present or explicitly desired in many natural and industrial processes, such as, flow over solid surfaces, cloud formation, pollination, combustion, and chemical mixing. Hence, a better understanding of turbulence can aid in fuel saving by reducing drag in the case of flow over solid surfaces, namely, cars, airplanes,...
doctoral thesis 2017
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Eisma, H.E. (author)
doctoral thesis 2017
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Pennings, P.C. (author)
This thesis describes the mechanisms with which tip vortex cavitation is responsible for broadband pressure fluctuations on ship propellers. Hypotheses for these are described in detail by Bosschers (2009). Validation is provided by three main cavitation-tunnel experiments, one on a model propeller and two on a stationary wing. These have...
doctoral thesis 2016
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Fiscaletti, D. (author)
The present work is an experimental and numerical investigation of the small-scale motions in turbulent free-shear flows. In the far-field turbulence of a jet at high Reynolds number (Re? = 350) hot-wire anemometry (HWA) is applied to measure time series of flow velocity. By filtering these time series, large- and small-scale velocity...
doctoral thesis 2016
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Drost, S. (author)
The efficiency of polymer extrusion processes can be severely limited by the occurrence of viscoelastic extrusion instabilities. In a para-aramid fibre spinning process, for example, a ?m-scale extrusion instability is responsible for the waste of tons of polymer per year. At present, a considerable amount of research literature is available on...
doctoral thesis 2015
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Tokgöz, S. (author)
Taylor-Couette flow is defined as the flow confined between two coaxial cylinders which can rotate independently. Several different flow states can be observed in the gap between the cylinders by changing the rotation speeds and the rotating directions of the cylinders. The aim of this thesis is to investigate the previously reported change of...
doctoral thesis 2014
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Warncke, N.G.W. (author)
This thesis studies the hydrodynamics of froth flotation, a process that is used in industry as a means of removing small inclusions from the treated liquid by gas bubble injection. This work is particularly motivated by the removal of aluminium and silicon oxides from liquid steel. Hydrodynamic aspects have a strong influence on the efficiency...
doctoral thesis 2014
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Oldenziel, G. (author)
Liquid droplets occur in many natural phenomena and play an important role in a large number of industrial applications. One of the distinct properties of droplets as opposed to solid particles is their ability to merge, or coalesce upon collision. Coalescence of liquid drops is of importance in for example the food industry, where the shelf...
doctoral thesis 2014
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Franken, M.J.Z. (author)
Despite the fact that moving droplets are very common, a moving contact line is a longstanding fundamental challenge in the field of fluid mechanics. This fundamental challenge is the main topic of this thesis in the context of ASML immersion lithography equipment. In Chapter 2 an overview of existing theoretical and experimental work is given,...
doctoral thesis 2014
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Zverkhovskyi, O. (author)
doctoral thesis 2014
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Kloosterman, A. (author)
The work described in this PhD thesis has been carried out to improve insight into the relation between changing vascular network structures and their corresponding hemodynamics. Accurate quantitative information about the changing hemodynamics has been obtained experimentally from developing extraembryonic vascular networks of chicken embryos,...
doctoral thesis 2013
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Kim, H. (author)
This thesis is a work on a contact line instability at a finite Reynolds number, 0 < Re < O(100). This problem corresponds to an immersion droplet applied in a liquid- immersion lithography machine. We perform extensive works to understand this instability problem by means of experimental, numerical, and theoretical ways. First, in order to...
doctoral thesis 2013
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Harleman, M.J.W. (author)
Previous research has shown that the addition of gas bubbles to a turbulent boundary layer in water can reduce the local skin-friction drag by up to 80%. Application of this technique to ships seems promising, but to date no significant drag reductions are obtained on full-scale ships. More knowledge about the drag reduction mechanism is...
doctoral thesis 2012
Searched for: contributor:"Westerweel, J. (promotor)"
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