- document
-
Peerbooms, W. (author), Nadorp, Tim (author), van der Heijden, A.E.D.M. (author), Breugem, W.P. (author)In the literature, two different frameworks exist for describing the rheology of solid/liquid suspensions: (1) the “viscous” framework in terms of the relative suspension viscosity, η<sub>r</sub>, as a function of the reduced solid volume fraction, f=f<sub>m</sub>, with f<sub>m</sub> the maximum flowable packing fraction, and (2) the ...journal article 2024
- document
-
Kamis, Y.E. (author), Prakash, Suriya (author), Breugem, W.P. (author), Eral, H.B. (author)We experimentally and numerically study the dynamics of a liquid jet issued from a rotating orifice, whose breakup is regulated by a vibrating piezo element. The helical trajectory of the spiralling jet yields fictitious forces varying along the jet whose longitudinal projections stretch and thin the jet, affecting the growth of perturbations....journal article 2023
- document
-
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
- document
-
Shajahan, M.T. (author), Breugem, W.P. (author)Particle-resolved Direct Numerical Simulations have been performed on the gravitational settling of mono-disperse solid spheres in a viscous fluid and triply periodic domain. In a comprehensive study, the bulk solid volume concentration was varied from ϕ=0.5 to 30%. To study the effect of inertia, three different Galileo numbers were...journal article 2023
- document
-
Keetels, G.H. (author), Chauchat, Julien (author), Breugem, W.P. (author)Reliable prediction of the erosion rate of sediment beds is important for many applications in coastal and river engineering. Theoretical understanding of empirically derived scaling relations is still lacking. This applies in particular for the scaling anomaly between low and high Shields number conditions. In this work, the erosion process is...journal article 2023
- document
-
Van Overveld, T. J.J.M. (author), Shajahan, M.T. (author), Breugem, W.P. (author), Clercx, H. J.H. (author), Duran-Matute, M. (author)When two spherical particles submerged in a viscous fluid are subjected to an oscillatory flow, they align themselves perpendicular to the direction of the flow leaving a small gap between them. The formation of this compact structure is attributed to a nonzero residual flow known as steady streaming. We have performed direct numerical...journal article 2022
- document
-
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
- document
-
Van Overveld, T. J.J.M. (author), Breugem, W.P. (author), Clercx, Herman J.H. (author), Duran-Matute, M. (author)The alignment of a pair of spherical particles perpendicular to a horizontally oscillating flow is attributed to a non-zero residual flow, known as steady streaming. This phenomenon is the basis of complex patterns in denser systems, such as particle chains and the initial stages of rolling-grain ripples. Previous studies on such self...journal article 2022
- document
-
Kramer, O.J.I. (author), van Schaik, C. (author), Hangelbroek, J.J. (author), de Moel, P.J. (author), Colin, M.G. (author), Amsing, M. (author), Boek, E.S. (author), Breugem, W.P. (author), Padding, J.T. (author), van der Hoek, J.P. (author)Liquid-solid fluidisation is frequently encountered in drinking water treatment processes, often to obtain a large liquid-solid interfacial surface area. A large surface area is crucial for optimal seeded crystallisation in full-scale softening reactors. Due to crystallisation, particles grow and migrate to a lower zone in the reactor which...journal article 2021
- document
-
Kramer, O.J.I. (author), de Moel, Peter J. (author), Kaveripuram Ramasamy, S.R. (author), Baars, Eric T. (author), van Vught, Wim H. (author), Breugem, W.P. (author), Padding, J.T. (author), van der Hoek, J.P. (author)Natural particles are frequently applied in drinking water treatment processes in fixed bed reactors, fluidised bed reactors, and sedimentation processes to clarify water and to concentrate solids. When particles settle, it has been found that, in terms of hydraulics, natural particles behave differently when compared to perfectly round spheres....journal article 2021
- document
-
Kamis, Y.E. (author), Eral, H.B. (author), Breugem, W.P. (author)Using a slender-jet approach, we numerically investigate the control of jet breakup using temperature modulation at the nozzle with a specified frequency and amplitude. Our results show that temperature modulation does lead to instability through capillary and Marangoni stresses, providing control of the droplet formation in terms of intact...journal article 2021
- document
-
Reurings, C. (author), Koussios, S. (author), Bergsma, O.K. (author), Breugem, W.P. (author), Vergote, K. (author), Paeshuyse, L. (author), Benedictus, R. (author)The purpose of this work is to experimentally establish the combined influence on the flow and thermal resistance of an exhaust pipe wall formed by a porous, compliant layer with overlying discrete roughness elements exposed to the pulsating exhaust gas flow of a combustion engine. Through measuring the streamwise pressure drop over and...journal article 2020
- document
-
Shajahan, M.T. (author), Breugem, W.P. (author)Macroscopic properties of sedimenting suspensions have been studied extensively and can be characterized using the Galileo number (Ga), solid-to-fluid density ratio (π<sub>p</sub>) and mean solid volume concentration (ϕ¯). However, the particle–particle and particle–fluid interactions that dictate these macroscopic trends have been...journal article 2020
- document
-
Brändle de Motta, J. C. (author), Simões Costa, P. (author), Derksen, J. J. (author), Peng, C. (author), Wang, L. P. (author), Breugem, W.P. (author), Estivalezes, J. L. (author), Vincent, S. (author), Climent, E. (author), Fede, P. (author), Barbaresco, P. (author), Renon, N. (author)During the last decade, many approaches for resolved-particle simulation (RPS) have been developed for numerical studies of finite-size particle-laden turbulent flows. In this paper, three RPS approaches are compared for a particle-laden decaying turbulence case. These methods are, the Volume-of-Fluid Lagrangian method, based on the viscosity...journal article 2019
- document
-
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
- document
-
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
- document
-
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
- document
-
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
- document
-
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
- document
-
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