Searched for: author%3A%22Poelma%2C+C.%22
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Hogendoorn, W.J. (author), Breugem, W.P. (author), Frank, David (author), Bruschewski, Martin (author), Grundmann, Sven (author), Poelma, C. (author)
Magnetic resonance imaging (MRI) experiments have been performed in conjunction with direct numerical simulations (DNS) to study neutrally buoyant particle-laden pipe flows. The flows are characterized by the suspension liquid Reynolds number (Res), based on the bulk liquid velocity and suspension viscosity obtained from Eilers' correlation,...
journal article 2023
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Nagalingam, Nagaraj (author), Raghunathan, Aswin (author), Korede, V.B. (author), Poelma, C. (author), Smith, C.S. (author), Hartkamp, Remco (author), Padding, J.T. (author), Eral, H.B. (author)
We demonstrate that a cavitation bubble initiated by a Nd:YAG laser pulse below breakdown threshold induces crystallization from supersaturated aqueous solutions with supersaturation and laser-energy-dependent nucleation kinetics. Combining high-speed video microscopy and simulations, we argue that a competition between the dissipation of...
journal article 2023
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Cornel, W.A. (author), Westerweel, J. (author), Poelma, C. (author)
Abstract: A novel experimental imaging-based method is presented for the non-intrusive determination of shock wave characteristics (i.e. shock wave speed and magnitude, and shock-induced liquid velocity) in a bubbly flow solely from gas bubble velocities. Shock wave speeds are estimated by the relative motion between gas bubbles at two...
journal article 2023
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van Meerkerk, M. (author), Poelma, C. (author), Hofland, Bas (author), Westerweel, J. (author)
We present an experimental study on the gas flow field development over a plunging breaking wave prior to impact on a vertical wall. The variability of wave impact pressure over repeated measurements is well known (Bagnold, 1939). The formation of instabilities on the wave crest are postulated to be the main source of impact pressure variability...
journal article 2022
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Hogendoorn, W.J. (author), Frank, David (author), Bruschewski, Martin (author), Poelma, C. (author)
Using magnetic resonance imaging we are able to obtain average velocity and volume fraction profiles in a pipe flow with a neutrally buoyant suspension. In this experimental work, the effect of increasing Reynolds number and particle volume fraction on shear-induced migration is studied. For increasing bulk volume fraction, the initially...
conference paper 2022
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Muller, K. (author), Greidanus, A.J. (author), Dash, A. (author), Poelma, C. (author)
The circular Taylor-Couette flow is one of the archetypical model systems for the study of flow transitions and dynamic pattern formation in experimental fluid dynamics. The emergence of the internal vortical flow structures are commonly visualized through a rheoscopic flow visualization, while their spatio-temporal dynamics can be extracted by...
conference paper 2022
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Gawandalkar, U.U. (author), Poelma, C. (author)
Abstract: The so-called ‘re-entrant jet’ is fundamental to periodic cloud shedding in partial cavitation. However, the exact physical mechanism governing this phenomenon remains ambiguous. The complicated topology of the re-entrant flow renders whole-field, detailed measurement of the re-entrant flow cumbersome. Hence, most studies in the...
journal article 2022
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Dash, A. (author), Hogendoorn, W.J. (author), Oldenziel, G. (author), Poelma, C. (author)
Abstract: Ultrasound imaging velocimetry (UIV) refers to the technique wherein ultrasound images are analysed with 2D cross-correlation techniques developed originally in the framework of particle image velocimetry. Applying UIV to opaque, particle-laden multiphase flows have long been considered to be an attractive prospect. In this study,...
journal article 2022
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Kaveripuram Ramasamy, S.R. (author), Poelma, C. (author), Breugem, W.P. (author)
Path instabilities of a sphere rising or falling in a quiescent Newtonian fluid have been studied experimentally. The rich palette of possible instabilities is dependent upon two dimensionless quantities, namely the Galileo number (Ga) and the particle/fluid mass density ratio (ρ¯). In recent literature, several (Ga,ρ¯) regime maps have been...
journal article 2022
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Nikolaidou, Lina (author), Laskari, A. (author), Poelma, C. (author), van Terwisga, T.J.C. (author)
An air layer within a liquid turbulent boundary layer (TBL) is formed by controlled air injection underneath a flat plate. The incoming boundary layer as well as the flow around the air layer were measured with planar particle image velocimetry (PIV). The effect of different incoming liquid flow characteristics on the air layer geometry is...
conference paper 2022
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Hogendoorn, W.J. (author), Chandra, B. (author), Poelma, C. (author)
We propose a scaling law for the onset of turbulence in pipe flow of neutrally buoyant suspensions. This scaling law, based on a large set of experimental data, relates the amplitude of the particle-induced perturbations ε to the critical suspension Reynolds number Res,c. Here ε is a function of the particle-to-pipe diameter ratio and the volume...
journal article 2022
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Dash, A. (author), Poelma, C. (author)
We revisit the laminar–turbulent transition of a fine-grained slurry in a large pipe. The combination of long measurement times in an industrial-scale facility and ultrasound imaging allows us to observe and address anomalous trends. Under turbulent conditions, the flow is homogeneous and steady. However, under laminar conditions, two types of...
journal article 2022
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Hogendoorn, W.J. (author), Chandra, B. (author), Poelma, C. (author)
Particle-laden pipe flows exhibit a gradual laminar-turbulent transition, beyond a critical volume fraction (φ). While classical transition behavior is characterized by the presence of turbulent puffs, this intermittent nature is absent for particle-induced transition. For small pipe-to-particle diameter ratios (D/d) even dilute systems...
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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Dash, A. (author), Hogendoorn, W.J. (author), Poelma, C. (author)
Abstract: We discuss empirical techniques to extract quantitative particle volume fraction profiles in particle-laden flows using an ultrasound transducer. A key step involves probing several uniform suspensions with varying bulk volume fractions from which two key volume fraction dependent calibration parameters are identified: the peak...
journal article 2021
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Kok, G. (author), Pelevic, N. (author), Chiribiri, A. (author), Milidonis, X. (author), Nazir, M. (author), Capstick, M. (author), Drost, S. (author), Poelma, C. (author), Schaeffter, T. (author)
In the medical sector, various imaging methodologies or modalities (e.g. MRI, PET, CT) are used to assess the health of various parts of the bodies of patients. One such investigation is the blood flow or perfusion of the heart muscle, expressed as the (blood) flow rate normalized by the mass of the volume of interest. Currently there is no...
journal article 2021
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Dash, A. (author), Anantharaman, Arjun (author), Poelma, C. (author)
We extend upon the known flow transitions in neutrally buoyant particle-laden Taylor-Couette flows by accessing higher suspension Reynolds numbers in a geometry with radius ratio and aspect ratio. Flow transitions for several particle volume fractions () are investigated by means of flow visualization experiments, in a flow driven by a...
journal article 2020
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Poelma, C. (author)
A review is presented of measurement techniques to characterise dispersed multiphase flows, which are not accessible by means of conventional optical techniques. The main issues that limit the accuracy and effectiveness of optical techniques are briefly discussed: cross-talk, a reduced signal-to-noise ratio, and (biased) data drop-out....
review 2020
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Thota Radhakrishnan, A.K. (author), Poelma, C. (author), van Lier, J.B. (author), Clemens, F.H.L.R. (author)
Transition from laminar to turbulent flow of non-Newtonian fluids is investigated using velocimetry data. These data are obtained by applying particle image velocimetry to images obtained through ultrasound imaging (echography). This yielded the observation of intermittent structures (puffs and slugs) that are formed during transition. Post...
journal article 2020
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van Eckeveld, A.C. (author), Westerweel, J. (author), Poelma, C. (author)
Severe vibrations and sound production can occur in dry gas flow through corrugated pipes. The addition of very small amounts of liquid to the dry gas flow potentially mitigates these flow-induced vibrations (FIVs) and noise. The different mechanisms behind this whistling mitigation are studied in this work, where acoustic measurements are...
journal article 2020
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