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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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- 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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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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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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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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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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Picano, F. (author), Breugem, W.P. (author), Mitra, D. (author), Brandt, L. (author)Shear thickening appears as an increase of the viscosity of a dense suspension with the shear rate, sometimes sudden and violent at high volume fraction. Its origin for noncolloidal suspension with non-negligible inertial effects is still debated. Here we consider a simple shear flow and demonstrate that fluid inertia causes a strong...journal article 2013
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Brändle de Motta, J.C. (author), Breugem, W.P. (author), Gazanion, B. (author), Estivalezes, J.L. (author), Vincent, S. (author), Climent, E. (author)A general model is presented for short-range hydrodynamic interactions and head-on particle-particle/wall collisions. The model has been embedded in two distinct numerical methods for fully resolved simulation of finite-size particles in a viscous fluid. It accounts for the material properties of the particles and lubrication effects prior to...journal article 2013
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- Breugem, W.P. (author), Simões Costa, P. (author) conference paper 2013
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Francesco, Picano (author), Breugem, W.P. (author), Luca, Brandt (author)Suspensions are often found in different processes and applications, e.g. sediment transport in environments or pharmaceutical engineering. The laminar regime in the semi-dilute or dense cases, non vanishing volume fraction, is usually characterized by the sometime spectacular rheological properties induced by the suspended phase. Much less...conference paper 2013
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Goudar Vishwanathappa, M. (author), Breugem, W.P. (author), Elsinga, G.E. (author)For channel flow, we explore how a hairpin eddy may reach a threshold strength required to produce additional hairpins by means of auto-generation. This is done by studying the interaction of two eddies with different initial strengths (but both below the threshold strength), initial sizes and initial streamwise spacing between them. The...conference paper 2013