Latest papers in fluid mechanics

Author(s): Christiane Schneide, Ambrish Pandey, Kathrin Padberg-Gehle, and Jörg Schumacher

Large-scale patterns in three-dimensional turbulent Rayleigh-Bénard convection in a large-aspect-ratio cell are probed by the clustering of Lagrangian particle trajectories.

[Phys. Rev. Fluids 3, 113501] Published Thu Nov 15, 2018

Author(s): Nima Mirzaeian and Kamran Alba

Intrusion of a particle-laden mixture into a pure fluid is studied experimentally within a duct. Applications are found in the discharge of slurries, mine tailings, pastes, sludge, effluents, and sewage. Exotic sedimentary, transitionary, and mixing regimes are found over various inclination angles.

[Phys. Rev. Fluids 3, 114301] Published Thu Nov 15, 2018

Author(s): A. Cazaubiel, G. Michel, S. Lepot, B. Semin, S. Aumaître, M. Berhanu, F. Bonnefoy, and E. Falcon

An experimental study reveals a new statistical regime for 1D propagation of deep-water gravity waves where coherent structures (solitons, extreme events) coexist with random waves. Such a state is predicted theoretically by integrable turbulence but thus far had not been observed in this context.

[Phys. Rev. Fluids 3, 114802] Published Tue Nov 13, 2018

Author(s): Ali Abbas Zaidi

Settling dynamics of non-Brownian particles is investigated using particle-resolved direct numerical simulations. There are two aims of this paper: first is to study the variation of particle velocity fluctuations with solid volume for a wide range of settling Reynolds number; second is to investiga...

[Phys. Rev. E 98, 053103] Published Fri Nov 09, 2018

Author(s): R. Miller, S. J. Garrett, P. T. Griffiths, and Z. Hussain

A stability analysis of the Blasius boundary layer formed by a fluid with a temperature-dependent viscosity is examined. The results inform whether hydrodynamically unstable flows may exist inside chemical vapor deposition reactors (CVD) and how a comprehensive CVD stability model can be developed.

[Phys. Rev. Fluids 3, 113902] Published Fri Nov 09, 2018

Author(s): Alexandros Charogiannis, Fabian Denner, Berend G. M. van Wachem, Serafim Kalliadasis, Benoit Scheid, and Christos N. Markides

Space/time-resolved film-thickness data are presented for liquid films flowing under an inverted planar substrate. Different flow regimes are observed depending on the inclination, liquid properties, and Reynolds number, with waves characterized by pronounced three-dimensionality and rivulet formation.

[Phys. Rev. Fluids 3, 114002] Published Fri Nov 09, 2018

Author(s): J. Yuan and M. Aghaei Jouybari

Current understanding of turbulence in the vicinity of surface roughness is mostly limited to narrow-scale or regular roughness geometries. A numerical analysis shows how various scales of a multiscale, realistic roughness affect friction, momentum balance, and turbulence production in the roughness sublayer.

[Phys. Rev. Fluids 3, 114603] Published Fri Nov 09, 2018

Author(s): Jason Reneuve, Julien Salort, and Laurent Chevillard

A nonlocal version of the Gross-Pitaevskii equation is investigated. The role of rotons in vortex reconnection is probed through numerical simulations of both local (standard) and nonlocal models. Observed dynamics are compared with the predictions of the local induction approximation.

[Phys. Rev. Fluids 3, 114602] Published Thu Nov 08, 2018

Author(s): Rommel J. Pabon, Lawrence Ukeiley, Mark Sheplak, and Casey Barnard Keane

A microelectromechanical-systems-based floating element wall-shear-stress sensor (1×1 mm) is validated in a turbulent boundary layer for its ability to measure characteristics of large-scale motions.

[Phys. Rev. Fluids 3, 114604] Published Thu Nov 08, 2018

Author(s): Seunghyun Cho, Jooha Kim, and Haecheon Choi

Longitudinal strips are suggested as a new device that can significantly increase the aerodynamic performance of a low Reynolds number airfoil at post-stall angles of attack. Its mechanism relies on the generation of corner vortices that delay flow separation on the airfoil suction surface.

[Phys. Rev. Fluids 3, 113901] Published Wed Nov 07, 2018

Author(s): John C. Nasaba and Anugrah Singh

We report on the pattern formation in a horizontal rotating cylinder fully filled with bidispersed suspension composed of non-Brownian settling and floating particles. The effect of particle mixing of different buoyancy and shape on the axial and radial pattern formation was investigated using flow ...

[Phys. Rev. E 98, 053102] Published Tue Nov 06, 2018

Author(s): Zvi Rusak, Yuxin Zhang, Jung J. Choi, and Shixiao Wang

A model problem of low-Mach number lean premixed reacting swirling flows with wall-separation zones in a contracting open chamber is studied. A theoretical feasibility for a technology of swirl-assisted combustion where the reaction zone is supported by a wall-separation zone is established.

[Phys. Rev. Fluids 3, 113201] Published Tue Nov 06, 2018

Author(s): Gigi Lin, John M. Frostad, and Gerald G. Fuller

Thin-film experiments with an interferometric apparatus show an absence of a strong relationship between interfacial elasticity and liquid entrainment in thin foam films, which can affect rational design of aesthetic and tactile properties in foaming consumer products.

[Phys. Rev. Fluids 3, 114001] Published Tue Nov 06, 2018

Author(s): N. Vorhauer, E. Tsotsas, and M. Prat

The flow of water vapor against temperature gradients naturally occurring in drying of porous media leads to condensation and simultaneous gas-liquid invasion of pore space. This phenomenon is studied with a model porous medium in a microfluidic device and a pore network model of drying and imbibition.

[Phys. Rev. Fluids 3, 114201] Published Tue Nov 06, 2018

Author(s): D. Lunz and P. D. Howell

Motivated by plasma particles impacting a liquid-metal divertor, an analysis is performed to investigate how a liquid’s free surface is deflected by a moving applied pressure. It is found that the plasma can be swept up and down the liquid in order to spread the heat load, however, this may induce dangerously large deflections.

[Phys. Rev. Fluids 3, 114801] Published Tue Nov 06, 2018

Author(s): Mpumelelo Matse, Peter Berg, and Michael Eikerling

A theoretical model is developed that describes nonlinear coupling between wall deformation and water and ion flows in a charged, deformable nanochannel whose viscoelasticity is governed by the Kelvin-Voigt model. Using continuum mean-field theories for mass and momentum conservation of the solid-li...

[Phys. Rev. E 98, 053101] Published Thu Nov 01, 2018

Author(s): Robert H. Davis and Alexander Z. Zinchenko

Hydrophobic particles are selectively separated from aqueous suspension by a novel oil-in-water binder. The collection efficiency is predicted in this work by a hydrodynamic trajectory analysis, and shown to be greatly enhanced by water permeation through the oil layer.

[Phys. Rev. Fluids 3, 113601] Published Thu Nov 01, 2018

Author(s): Alexandros Alexakis

An investigation of how large-scale flow is affected by changes in the properties of small-scale flows, the layer thickness, and viscosity is presented.

[Phys. Rev. Fluids 3, 114601] Published Thu Nov 01, 2018

Author(s): Yogesh Jethani, Kamal Kumar, A. Sameen, and Manikandan Mathur

Local stability equations are solved along closed fluid particle trajectories in the cylinder wake for Reynolds numbers in the range of 50 to 300. A bifurcation is shown to occur at Re≈250 and is argued to be related to the emergence of the well-known mode-B secondary instability.

[Phys. Rev. Fluids 3, 103902] Published Wed Oct 31, 2018

Author(s): Linlin Fei, Andrea Scagliarini, Andrea Montessori, Marco Lauricella, Sauro Succi, and Kai H. Luo

We further develop a two-range pseudopotential Lattice Boltzmann method for soft flowing systems using tunable surface tension and viscosity ratio. It is applicable to multicomponent fluids with a viscosity-independent disjoining pressure, a key to the microfluidic design of new porous materials.

[Phys. Rev. Fluids 3, 104304] Published Wed Oct 31, 2018