Searched for: subject%3A%22cavitation%22
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Nanda, S. (author)
The research presented in this thesis aims at understanding how gases influence the cavitating vortex generated by a wing tip in a stationary flow. Gases in the flow occur as non-condensible microbubbles as well as gases dissolved in the liquid. They are typically abundant in surface flows. For studying how dissolved gases influence a cavitating...
doctoral thesis 2023
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Delaporte, Cyril (author)
Hydrofoils can under certain circumstances cause a phase change from liquid water to water vapor. This phenomenon is called cavitation and is caused by the low pressure over the hydrofoil when the vessel exceeds a certain velocity though the water. Cavitation can take different forms depending the angle of attack α and the flow conditions which...
master thesis 2023
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Melissaris, Themistoklis (author)
Cavitation is the formation of vapor pockets in a liquid due to a pressure drop or an increase in speed. Cavitation nuisance can be disastrous for mechanical components, and therefore needs to be controlled from an early design stage. However, predicting cavitation dynamics using CFD (Computational Fluid Dynamics) and therefore the performance...
doctoral thesis 2023
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Kalikatzarakis, Miltiadis (author), Coraddu, A. (author), Atlar, Mehmet (author), Gaggero, Stefano (author), Tani, Giorgio (author), Oneto, Luca (author)
For propeller-driven vessels, cavitation is the most dominant noise source producing both structure-borne and radiated noise impacting wildlife, passenger comfort, and underwater warfare. Physically plausible and accurate predictions of the underwater radiated noise at design stage, i.e., for previously untested geometries and operating...
journal article 2023
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Nagalingam, Nagaraj (author), Raghunathan, Aswin (author), Korede, V.B. (author), Overmars, E.F.J. (author), Hung, S. (author), Hartkamp, Remco (author), Padding, J.T. (author), Smith, C.S. (author), Eral, H.B. (author)
Optofluidic devices have revolutionized the manipulation and transportation of fluid at smaller length scales ranging from micrometers to millimeters. We describe a dedicated optical setup for studying laser-induced cavitation inside a microchannel. In a typical experiment, we use a tightly focused laser beam to locally evaporate the solution...
journal article 2023
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Li, H. (author), Li, X. (author), Collado Lara, G. (author), Lattwein, K.R. (author), Mastik, Frits (author), Beurskens, Robert (author), van der Steen, A.F.W. (author), Verweij, M.A. (author), de Jong, N. (author), Kooiman, Klazina (author)
Ultrasound contrast-mediated medical imaging and therapy both rely on the dynamics of micron- and nanometer-sized ultrasound cavitation nuclei, such as phospholipid-coated microbubbles and phase-change droplets. Ultrasound cavitation nuclei respond non-linearly to ultrasound on a nanosecond time scale that necessitates the use of ultra-high...
journal article 2023
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Huang, Tzu-Yao (author)
Tip vortex cavitation around the marine propeller is the primary source of the underwater noises emitted by ships. Investigating the tip vortex inception is important to understand the aforementioned side effect. The water quality, highly related to the bubbles population, surrounding the tip vortex is crucial to the tip vortex cavitation...
master thesis 2022
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Wang, Fanglun (author)
The fundamental research of cavitation has been a hot topic for decades, while a particle image velocimetry (PIV) measurement on single bubble dynamics is uncommon due to many technical hassles. The involved flow field is small in space and highly unsteady in time, so it challenging the spatial and temporal resolution that current PIV techniques...
master thesis 2022
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van Bemmel, Jeroen (author)
Propellers are used to propel the vast majority of ships. They are most commonly made out of Nickel-Aluminum-Bronze alloys. This is due to their superior characteristics over other metals in terms of strength and corrosion resistance. Metal propellers are assumed to be rigid and undeformable. Current research opts to construct propellers out of...
master thesis 2022
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Raghunathan, Aswin (author)
Crystallization is one of the most sought after separation and purification technique in the process industries. However, the fundamental understanding on the formation of crystals poses quite a challenge due to the inherent complexity and stochasticity associated with the process. In the past, several attempts put forth to control crystal...
master thesis 2022
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Melissaris, Themistoklis (author), Schenke, S. (author), Bulten, Norbert (author), van Terwisga, T.J.C. (author)
Propeller cavitation erosion prediction at an early design stage is becoming more and more important since it is one of the key constraints in the search for maximum propeller efficiency. Despite the experience from model tests, cavitation erosion research on actual ship scale is very limited. In this study, an attempt is made to assess the...
journal article 2022
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Fujikawa, Toshihide (author), Egashira, R. (author), Hooman, K. (author), Yaguchi, H. (author), Masubuchi, H. (author), Fujikawa, S. (author)
Theory of dynamical cavitation threshold for vapor and non-condensable gas bubble nuclei is proposed based on a model equation constructed from Rayleigh-Plesset equation for glycerol, the liquid with viscosity higher than that of water by 1500 times, under a finite duration of strong tension. The model equation is ascertained to be valid in...
journal article 2022
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Kalikatzarakis, Miltiadis (author), Coraddu, A. (author), Atlar, Mehmet (author), Gaggero, Stefano (author), Tani, Giorgio (author), Villa, Diego (author), Oneto, Luca (author)
The potential impact of underwater radiated noise from maritime operations on marine fauna has become an important issue. The most dominant noise source on a propeller-driven vessel is propeller cavitation, producing both structure-borne and radiated noise, with a broad spectrum that covers a wide range of frequencies. To ensure acceptable...
journal article 2022
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Nanda, S. (author), Westerweel, J. (author), van Terwisga, T.J.C. (author), Elsinga, G.E. (author)
Following their inception, vortex cavities emanating from stationary wing tips in cavitation tunnels are often observed to grow. These effects are usually attributed to the free and dissolved non-condensable gases in the liquid. However, a detailed mechanism for the cavity's growth is not known. Consequently, the repeatability of vortex...
journal article 2022
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Klapwijk, M.D. (author)
There is increasing attention for the effects of anthropogenic underwater radiated noise (URN) on marine fauna. This is expected to lead to regulations with respect to the maximum permitted sound emissions of ships. It is known that cavitating tip vortices, generated by ship propellers, are some of the key contributors to URN. Consequently,...
doctoral thesis 2021
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Sharoubim, Sarah (author)
Often, vessels have multiple operation modes that are specialised for a certain task. If a vessel is employed with a controllable pitch propeller(CPP), the blade pitch can be adjusted, adding a degree of freedom to the system. This advantage creates the possibility to increase the diversity of operation modes of the vessel and allows for...
master thesis 2021
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in 't Veld, Maarten (author)
One classic challenge in pump operation is the occurrence of cavitation. Cavitation is the forming of vapour bubbles in a fluid due to a local drop in pressure, followed by a subsequent implosion of those bubbles due to an increase in pressure. The vapour formed can significantly decrease pump efficiency and the implosion can be detrimental to...
master thesis 2021
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Klapwijk, M.D. (author), Lloyd, T. (author), Vaz, G. (author), van Terwisga, T.J.C. (author)
The Delft Twist 11 Hydrofoil is a common test case for investigating the interaction between turbulence and cavitation modelling in computational fluid dynamics. Despite repeated investigations, results reported for the lift and drag coefficient are accompanied by significant uncertainties, both in experimental and numerical studies. When...
journal article 2021
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Jahangir, S. (author), Ghahramani, Ebrahim (author), Neuhauser, Magdalena (author), Bourgeois, Sébastien (author), Bensow, Rickard E. (author), Poelma, C. (author)
The objective of this study is to investigate the collapsing behavior of cavitation, which leads to the erosion of material. An experimental examination was conducted in a channel with a semi-circular cylinder obstacle, which serves as a “vortex cavity” generator. Cavitation was achieved by employing a range of pressure differences over the...
journal article 2021
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Schenke, S. (author)
Cavitation erosion is a problem in the design of a wide range of fluid machinery involving liquid flows. Ship propellers, rudders, hydro pumps and turbines or diesel injectors are some of the most prominent examples. Cavitation occurs at locations of high local flow velocity, where the pressure may drop so low that the liquid phase vaporizes....
doctoral thesis 2020
Searched for: subject%3A%22cavitation%22
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