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Benschop, H.O.G. (author), Greidanus, A.J. (author), Delfos, R. (author), Westerweel, J. (author), Breugem, W.P. (author)
We investigate the deformation of a linear viscoelastic compliant coating in a turbulent flow for a wide range of coating parameters. A one-way coupling model is proposed in which the turbulent surface stresses are expressed as a sum of streamwise-travelling waves with amplitudes determined from the stress spectra of the corresponding flow...
journal article 2019
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Benschop, H.O.G. (author), Guerin, A. J. (author), Brinkmann, A. (author), Dale, M. L. (author), Finnie, A. A. (author), Breugem, W.P. (author), Clare, A. S. (author), Stübing, D. (author), Price, C (author), Reynolds, K. J. (author)
The manufacture and preliminary testing of a drag-reducing riblet texture with fouling-control properties is presented. The commercial fouling-release product Intersleek® 1100SR was modified to manufacture riblet-textured coatings with an embossing technology. Hydrodynamic drag measurements in a Taylor–Couette set-up showed that the modified...
journal article 2018
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Charruault, F.T. (author), Greidanus, A.J. (author), Breugem, W.P. (author), Westerweel, J. (author)
The present study introduces an experimental technique based on a Free Surface-Synthetic Schlieren (FS-SS) method in order to characterize free surfaces subjected to strong deformations. Current synthetic Schlieren methods are based on local image correlation and thus limited to rather weak image deformations, implying that they can only resolve...
conference paper 2018
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Benschop, H.O.G. (author), Breugem, W.P. (author)
A bird-feather-inspired herringbone riblet texture was investigated for turbulent drag reduction. The texture consists of blade riblets in a converging/diverging or herringbone pattern with spanwise wavelength Λf. The aim is to quantify the drag change for this texture as compared to a smooth wall and to study the underlying mechanisms. To that...
journal article 2017
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Picano, Francesco (author), Simões Costa, P. (author), Breugem, W.P. (author), Brandt, Luca (author)
Dense suspensions are usually investigated in the laminar limit where inertial effects are insignificant. In this regime, the main effect of the suspended phase is to alter the rheological behavior of the flow which always displays higher effective viscosity with respect to the carrier fluid. When the flow rate is high enough, i.e. at high...
conference paper 2017
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Simões Costa, P. (author), Picano, Francesco (author), Brandt, Luca (author), Breugem, W.P. (author)
The macroscopic behavior of dense suspensions of neutrally buoyant spheres in turbulent plane channel flow is examined. We show that particles larger than the smallest turbulence scales cause the suspension to deviate from the continuum limit in which its dynamics is well described by an effective suspension viscosity. This deviation is...
journal article 2016
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Goudar Vishwanathappa, M. (author), Breugem, W.P. (author), Elsinga, G.E. (author)
For channel flow, we explore how commonly found weak eddies can still auto-generate and produce new eddies. Before, only strong eddies (above a threshold strength) were considered to auto-generate. Such strong eddies are rarely observed in actual turbulent flows however. Here, the evolution of two weak conditional eddies with different initial...
journal article 2016
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Otto, I.A. (author), van Doremalen, R.F.M. (author), Melchels, F.P.W. (author), Kolodzynski, M.N. (author), Pouran, B. (author), Malda, Jos (author), Kon, M. (author), Breugem, C.A. (author)
journal article 2016
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Goudar Vishwanathappa, M. (author), Breugem, W.P. (author), Jodai, Y. (author), Elsinga, G.E. (author)
For channel flow, we explore how the interaction of weak eddies produces additional eddies by means of auto-generation. This is done by DNS of two eddies with different initial strengths, initial sizes and initial stream-wise spacing between them. The numerical procedure followed is similar to Zhou et al[1]. The two eddies merge into a single...
conference paper 2016
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Costa, P. (author), Boersma, B.J. (author), Westerweel, J. (author), Breugem, W.P. (author)
We present a collision model for particle-particle and particle-wall interactions in interface-resolved simulations of particle-laden flows. Three types of interparticle interactions are taken into account: (1) long- and (2) short-range hydrodynamic interactions, and (3) solid-solid contact. Long-range interactions are incorporated through an...
journal article 2015
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Picano, F. (author), Costa, P. (author), Breugem, W.P. (author), Brandt, L. (author)
Dense suspensions are usually investigated in the laminar limit where inertial effects are insignificant. When the flow rate is high enough, i.e. at high Reynolds number, the flow may become turbulent and the interaction between solid and liquid phases modifies the turbulence we know in single-phase fluids. In the present work, we study...
conference paper 2015
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Dense suspensions are usually investigated in the laminar limit where inertial effects are insignificant. When the flow rate is high enough, i.e. at high Reynolds number, the flow may become turbulent and the interaction between solid and liquid phases modifies the turbulence we know in single-phase fluids. In the present work, we study...
conference paper 2015
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Highly porous materials are found in various industrial applications and environmental flows. In previous studies it was found that a turbulent flow along a highly porous wall experiences a higher skin friction as compared to a solid wall with similar surface roughness when the so-called permeability Reynolds number (Re_K) is larger than O(1)....
conference paper 2015
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The use of drag reducing surface textures is a promising passive method to reduce fuel consumption. Probably most wellknown is the utilisation of shark-skin inspired ridges or riblets parallel to the mean flow. They can reduce drag up to 10%. Recently another bio-inspired texture based on bird flight feather riblets has been proposed. It differs...
conference paper 2015
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Benschop, H.O.G. (author), Westerweel, J. (author), Breugem, W.P. (author)
The use of drag reducing surface textures is a promising passive method to reduce fuel consumption. Probably most wellknown is the utilisation of shark-skin inspired ridges or riblets parallel to the mean flow. They can reduce drag up to 10%. Recently another bio-inspired texture based on bird flight feather riblets has been proposed. It differs...
conference paper 2015
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Inertial regimes in a channel flow of suspension of finite-size neutrally buoyant particles are studied for a wide range of Reynolds numbers: $500 \le Re\le 5000$, and particle volume fractions: $0 \le \Phi \le 0.3$. The flow is classified in three different regimes according to the phase-averaged stress budget across the channel \cite...
conference paper 2015
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Lashgari, I. (author), Picano, F. (author), Breugem, W.P. (author), Brandt, L. (author)
Inertial regimes in a channel flow of suspension of finite-size neutrally buoyant particles are studied for a wide range of Reynolds numbers: 500 Re 5000, and particle volume fractions: 0 0:3. The flow is classified in three different regimes according to the phase-averaged stress budget across the channel [2]. The laminar viscous regime at low...
conference paper 2015
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Lashgari, I. (author), Picano, F. (author), Breugem, W.P. (author), Brandt, L. (author)
We study the transition from laminar to turbulent flow in a channel seeded with finite-size neutrally buoyant particles. A fixed ratio of 10 between the channel height and the particle diameter is considered. The flow is examined in the range of Reynolds numbers 500 ? Re ? 5000 and the particle volume fractions 0.001 ? ? ? 0.3. We report a non...
journal article 2015
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Lashgari, I. (author), Picano, F. (author), Breugem, W.P. (author), Brandt, L. (author)
The aim of this Letter is to characterize the flow regimes of suspensions of finite-size rigid particles in a viscous fluid at finite inertia. We explore the system behavior as a function of the particle volume fraction and the Reynolds number (the ratio of flow and particle inertia to viscous forces). Unlike single-phase flows, where a clear...
journal article 2014
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Lambert, R.A. (author), Picano, F. (author), Breugem, W.P. (author), Brandt, L. (author)
A numerical study of swimming particle motion and nutrient transport is conducted for a semidilute to dense suspension in a thin film. The steady squirmer model is used to represent the motion of living cells in suspension with the nutrient uptake by swimming particles modelled using a first-order kinetic equation representing the absorption...
journal article 2013
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