Searched for: subject%3A%22Bubbles%22
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Mandalahalli, M.M. (author)
Bubbly flows are ubiquitously found in natural systems and are widely used in (bio)-chemical and energy-producing processes. A variety of design options, ease of maintenance, and a large operability window make bubble columns a commonplace across industries, ranging from oil processing to biotechnology and electrolyzers. Despite their wide...
doctoral thesis 2024
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Puiman, L. (author)
One of the major challenges mankind faces nowadays is combating climate change. A substantial fraction of greenhouse gases are released by industrial processes, as steelmaking, (oil)refinery and waste processing. Emissions from these processes can partly be prevented with a recently developed technology called gas fermentation. Within this...
doctoral thesis 2024
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Dhirde, Mayur (author)
The offshore wind industry is rapidly advancing, expected to play a crucial role in renewable energy production, with a growing emphasis on addressing associated environmental concerns, particularly the impact of underwater noise generated during the installation of wind turbines. In response, bubble curtain technology (BCT) has emerged as a...
master thesis 2024
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Volger, R. (author), Puiman, L. (author), Haringa, C. (author)
The growing global population and heightened concern for climate change leads to increased interest in utilizing microbial fermentations to replace polluting production processes for e.g., plastics, fuels, and animal proteins. Computational fluid dynamics (CFD) is a valuable tool for accelerating the scale-up and optimization of large-scale...
review 2024
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Bleeker, J.J. (author), van Kasteren, Celine (author), van Ommen, J.R. (author), Vermaas, D.A. (author)
To make green hydrogen more economically attractive, the energy losses in alkaline electrolysis need to be minimized while operating at high current densities (1 A cm<sup>−2</sup>). At these current densities the ohmic resistance and gas bubbles effects contribute largely to the energy losses. To mitigate the gas bubbles losses, we...
journal article 2024
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El Mellas, I. (author), Samkhaniani, N. (author), Falsetti, C. (author), Stroh, A. (author), Icardi, M. (author), Magnini, M. (author)
Micro-pin-fin evaporators are a promising alternative to multi-microchannel heat sinks for two-phase cooling of high power-density devices. Within pin-fin evaporators, the refrigerant flows through arrays of obstacles in cross-flow and is not restricted by the walls of a channel. The dynamics of bubbles generated upon flow boiling and the...
journal article 2024
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Mertens, C. (author), Grille Guerra, A. (author), van Oudheusden, B.W. (author), Fehrs, Michael (author), Ritter, Markus R. (author)
The effects of the wing skin distortion on the boundary layer of a highly flexible wing are analyzed in a wind tunnel experiment using infrared thermography measurements. Considerable differences in the boundary layer flow are observed when comparing the sections of the wing near the ribs, where the design shape of the wing is preserved, and...
book chapter 2024
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Tziaros, Filotas (author)
The need to reduce greenhouse gas emissions is emergent throughout every industrial sector worldwide. For aviation, this has opened a market gap for small scale electric aircraft configurations (e-V/STOL). These configurations are very diverse and they are classified based on how lift is obtained. However, their flight...
master thesis 2023
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Haverlag, Hein (author)
In this research project, multiphase behaviour in zero gap alkaline water electrolyzers is investigated, focusing on the influence of various parameters including current density, electrode-wall distance and electrode height. This involves a cell containing a vertical electrode pair separated by a membrane submerged in an electrolyte that has a...
master thesis 2023
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Deiters, Gilles (author)
In an effort to make water electrolysis more efficient and simple, flow-through electrolyzers eliminate the need for a gas-separating membrane between the electrodes. However, replacing the membrane with a forced flow field brings new challenges and considerations. In this research, the design of a flow-through electrolyzer is optimized for...
master thesis 2023
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Rajora, A. (author)
The primary objective of this work is to provide new analytical models to support the theoretical understanding of multiphase flows in various electrochemical systems. Most of the previous works in this field use either experiments or numerical simulations to understand the hydrodynamics of the multiphase flows. In this thesis, various new...
doctoral thesis 2023
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Pektaş, Mehmet (author)
A water electrolyzer is an electrochemical device that produces hydrogen and oxygen from water via electricity. A sustainable way of producing hydrogen with renewable electricity, also known as green hydrogen, could enable its use in decarbonisation of sectors that depend on fossil fuels. However, to scale up the production of green hydrogen,...
master thesis 2023
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Rajora, A. (author), Haverkort, J.W. (author)
Understanding multiphase flow close to the electrode surface is crucial to the design of electrolyzers, such as alkaline water electrolyzers for the production of green hydrogen. Vertical electrodes develop a narrow gas plume near their surface. We apply the integral method to the mixture model. Considering both exponentially varying and step...
journal article 2023
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Peng, Y. (author), Jarquin Laguna, A. (author), Tsouvalas, A. (author)
Underwater noise from offshore pile driving has raised significant concerns over its ecological impact on marine life. To protect the marine environment and maintain the sustainable development of wind energy, strict governmental regulations are imposed. Assessment and mitigation of underwater noise are usually required to ensure that sound...
journal article 2023
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Liu, Minghui (author), Wang, Ju (author), Peng, Z. (author)
To investigate energy-saving approaches in wastewater treatment plants and decrease aeration energy consumption, this study successfully established a floc-granule coexistence system in a sequencing batch airlift reactor (SBAR) employing micro-bubble aeration. The analysis focused on granule formation and pollutant removal under various...
journal article 2023
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Saha, S. (author), Luckham, Paul F. (author), Garbin, V. (author)
Hypothesis: High-frequency interfacial rheology of complex interfaces remains challenging yet it is central to the performance of multiphase soft matter products. We propose to use ultrasound-driven bubble dynamics to probe the high-frequency rheology of a colloid monolayer used as model system with controlled interactions and simultaneous...
journal article 2023
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Shi, Rui (author), Wüthrich, D. (author), Chanson, Hubert (author)
Transient motion, turbulence and bubble dynamics make any velocity quantification extremely difficult in unsteady gas–liquid flows. In the present study, novel Eulerian and Lagrangian techniques of velocimetry were developed, using both intrusive and non-intrusive measurements. The selected unsteady gas–liquid flow was a breaking bore,...
journal article 2023
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Shi, Rui (author), Wüthrich, D. (author), Chanson, Hubert (author)
Continuing from the part 1 (Shi et al., 2022) this paper presents an experimental investigation of transient void fraction and bubble statistics in a highly turbulent breaking bore with Fr<sub>1</sub>=2.4. The measurements were conducted using a combination of dual-tip phase-detection probes and an ultra-high-speed video camera. The enclosed...
journal article 2023
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Sarker, D. (author), Schinkel, C.V. (author), Portela, L. (author)
This study reports the effect of N<sub>2</sub> and CO<sub>2</sub> bubbles on dilute to dense gas-liquid two-phase bubbly flow. A shadowgraph imaging technique captured bubble images at a high spatiotemporal resolution. The recordings of bubble images allow us to compute gas fraction distribution. It requires challenging segmentation and gas...
journal article 2023
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Kim, S. (author), Curko, Josip (author), Matosic, Marin (author), Herrera, Aridai (author), Lopez-Vazquez, Carlos M. (author), Brdjanovic, Damir (author), Garcia, H. (author)
To investigate the influence of high-pressure and shear effects introduced by a concentrated oxygen supply system on the membrane filtration performance, a laboratory-scale membrane bioreactor (MBR) fed artificial municipal wastewater was operated continuously for 80 days in four phases equipped with different aerations systems: (P1) bubble...
journal article 2023
Searched for: subject%3A%22Bubbles%22
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