Physical Review Fluids
Author(s): Hadis Matinpour, Sean Bennett, Joseph Atkinson, and Michele Guala
Experiments are conducted to study the effects of suspended sediment on flow dynamics in a mixing box. Results from particle image velocimetry, providing the velocity of the sediment and fluid phases separately, demonstrate the formation of a stratified layer where turbulent modulation increases.
[Phys. Rev. Fluids 4, 074605] Published Thu Jul 25, 2019
Author(s): Fuqiang Chu, Xuan Zhang, Shaokang Li, Haichuan Jin, Jun Zhang, Xiaomin Wu, and Dongsheng Wen
Near the freezing ice front in sessile droplets, air dissolved in the liquid water is observed to separate out to form many isolated bubbles, making the ice droplets porous media instead of tight ice beads.
[Phys. Rev. Fluids 4, 071601(R)] Published Tue Jul 23, 2019
Effect of streamwise cross-sectional variation on liquid retention in liquid-infused substrates under an external flow
Author(s): L. Mazor, H. A. Stone, and I. Jacobi
Streamwise variations in the cross section of liquid-infused substrates are shown to affect their ability to retain liquid when exposed to an external, immiscible shear flow, with potential implications for the design and manufacturing of omniphobic and drag-reducing surfaces.
[Phys. Rev. Fluids 4, 074003] Published Tue Jul 23, 2019
Author(s): Michael MacDonald, Nicholas Hutchins, Detlef Lohse, and Daniel Chung
An effective scaling exponent between the Nusselt and Rayleigh numbers of 0.42 is predicted for fully rough turbulent thermal convection in the ultimate regime. This is distinct from the value of 0.38 for smooth walls and from 0.5 for the asymptotic (infinite Rayleigh number) ultimate regime.
[Phys. Rev. Fluids 4, 071501(R)] Published Mon Jul 22, 2019
Author(s): Andrea Montessori, Marco Lauricella, Adriano Tiribocchi, and Sauro Succi
A multicomponent lattice Boltzmann method with a force term for the effects of the near-contact interactions is applied to two droplets colliding and to emulsion production in microchannels.
[Phys. Rev. Fluids 4, 072201(R)] Published Fri Jul 19, 2019
Author(s): Shijian Wu and Hadi Mohammadigoushki
Formation of an unusually extended wake behind a falling sphere in a shear thickening dilute micellar solution (CTAB/5mS) is reported. It is suggested that this behavior is linked to flow-induced micellar structure formation where micelles transition from rodlike to wormlike micelles around the falling sphere.
[Phys. Rev. Fluids 4, 073303] Published Fri Jul 19, 2019
Author(s): Susanne Horn and Jonathan M. Aurnou
Centrifugal buoyancy affects the flow structures and the heat transport in all rotating convective experiments. Numerical simulations are used to provide predictions of the centrifugal effects expected to arise in laboratory studies of the dynamically rich system of Coriolis-centrifugal convection.
[Phys. Rev. Fluids 4, 073501] Published Fri Jul 19, 2019
Author(s): Erwan Crestel, Ladislav Derzsi, Hugo Bartolomei, Jérôme Bibette, and Nicolas Bremond
The flow of two immiscible liquids or fluids in bounded systems where confinement geometry varies can lead to drop or bubble formation. A comprehensive experimental investigation on such an emulsification, or foaming process, occurring at the end of a glass rectangular tube is presented.
[Phys. Rev. Fluids 4, 073602] Published Fri Jul 19, 2019
Author(s): Georges Gauthier and Philippe Gondret
We conduct experiments to examine the compaction dynamics of a liquid immersed granular packing under an upward flow which is either continuous or made up of repeated short bursts. We find that compaction is possible in the continuous case and compaction efficiency can be enhanced for short bursts.
[Phys. Rev. Fluids 4, 074308] Published Fri Jul 19, 2019
Author(s): Brener L. O. Ramos, William R. Wolf, Chi-An Yeh, and Kunihiko Taira
Large-eddy simulations are performed to study active flow control of deep dynamic stall for an SD7003 airfoil in plunging motion. For some frequencies, flow actuation disrupts the formation of the dynamic stall vortex, leading to drag reduction, while lift is almost unaffected.
[Phys. Rev. Fluids 4, 074603] Published Fri Jul 19, 2019
Author(s): Ehsan Irani, Pinaki Chaudhuri, and Claus Heussinger
The flow of a dense dispersion with short-range attractive forces is simulated. Discontinuous shear thinning occurs via rapid loss of particle-tangential viscous dissipation. The phenomenon is closely connected to discontinuous shear thickening, where tangential dissipation is due to solid friction.
[Phys. Rev. Fluids 4, 074307] Published Thu Jul 18, 2019
Author(s): Dalton V. Anderson, Michelle D. Maiden, and Mark A. Hoefer
Quantitative boundary control of buoyant, interfacial dynamics between two high-viscosity-contrast Stokes fluids is achieved by the technique of characteristic tracking. This enables the experimental generation of desired wave breaking profiles that produce dispersive shock waves and solitons.
[Phys. Rev. Fluids 4, 074804] Published Wed Jul 17, 2019
Author(s): Guangzhao Zhou and Andrea Prosperetti
The gradual expansion of large bubbles rising in a liquid-filled tube can become violent in the last few seconds before reaching the tube top. This process is responsible for Strombolian volcanic eruptions and for accidents in deep-water oil drilling such as the 2010 Deepwater Horizon explosion.
[Phys. Rev. Fluids 4, 073903] Published Tue Jul 16, 2019
Author(s): Sophie A. W. Calabretto and James P. Denier
A computational study shows that the flow induced by a sphere rotating in an otherwise quiescent fluid is convectively unstable to spiral vortices, which once induced are swept down through the sphere’s boundary layer and then out into the radial jet that emanates from sphere’s equator.
[Phys. Rev. Fluids 4, 073904] Published Tue Jul 16, 2019
Author(s): Daniel T. Paterson, Tom S. Eaves, Duncan R. Hewitt, Neil J. Balmforth, and D. Mark Martinez
A combined theoretical and experimental study is presented for rapid flow-induced compaction of a fibrous porous medium. The model is used to understand the dynamics of a standard test for pulp suspensions: the Canadian Standard Freeness test, which depends sensitively on the solid bulk viscosity.
[Phys. Rev. Fluids 4, 074306] Published Tue Jul 16, 2019
Author(s): Dennis Bakhuis, Varghese Mathai, Ruben A. Verschoof, Rodrigo Ezeta, Detlef Lohse, Sander G. Huisman, and Chao Sun
Despite tremendous turbulent fluctuation in a high-Reynolds number Taylor-Couette flow, dispersed millimetric fibers show a preferred alignment with respect to the inner cylinder of the apparatus. Using a simplified model based on Jeffery’s equations, the orientation can be reasonably predicted.
[Phys. Rev. Fluids 4, 072301(R)] Published Mon Jul 15, 2019
Author(s): Bernhard Vowinckel, Edward Biegert, Paolo Luzzatto-Fegiz, and Eckart Meiburg
Mud is widely present in the environment and it can bind contaminants or nutrients. Since particles that make up mud are small and sticky, it is difficult to perform precise measurements. To this end, we present a numerical framework, which yields results that have so far been impossible to obtain.
[Phys. Rev. Fluids 4, 074305] Published Mon Jul 15, 2019
Author(s): Mélissa D. Menu, Sébastien Galtier, and Ludovic Petitdemange
An inverse cascade of hybrid helicity is observed in direct numerical simulations of 3D magnetohydrodynamics with both an imposed magnetic field and a rotation rate. The impact of the tilt angle between the two axes and of the polarized forcing is discussed.
[Phys. Rev. Fluids 4, 073701] Published Fri Jul 12, 2019
Author(s): David B. Stein and Michael J. Shelley
We develop a coarse-grained Brinkman-type model for the dynamics of ordered arrays of immersed fibers. This approach provides a simple framework for the mathematical analysis and efficient numerical solution of problems including fiber-fluid rheology, soft valves, and waves within driven fiber beds.
[Phys. Rev. Fluids 4, 073302] Published Tue Jul 09, 2019
Author(s): Annette Cazaubiel, Florence Haudin, Eric Falcon, and Michael Berhanu
Two surface waves are forced in a cylindrical tank. Their nonlinear interaction generates a third wave not obeying the dispersion relation, whose presence is shown using a laser vibrometer or a three-dimensional free-surface reconstruction. We explain this result as a forced three-wave interaction.
[Phys. Rev. Fluids 4, 074803] Published Tue Jul 09, 2019