Latest papers in fluid mechanics

Particle velocity distributions and velocity fluctuations of non-Brownian settling particles by particle-resolved direct numerical simulation

Physical Review E - Fri, 11/09/2018 - 10:00

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

Stability of the Blasius boundary layer over a heated plate in a temperature-dependent viscosity flow

Physical Review Fluids - Fri, 11/09/2018 - 10:00

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

Experimental investigations of liquid falling films flowing under an inclined planar substrate

Physical Review Fluids - Fri, 11/09/2018 - 10:00

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

Topographical effects of roughness on turbulence statistics in roughness sublayer

Physical Review Fluids - Fri, 11/09/2018 - 10:00

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

Structure, dynamics, and reconnection of vortices in a nonlocal model of superfluids

Physical Review Fluids - Thu, 11/08/2018 - 10:00

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

Characteristics of turbulent boundary layer large scale motions using direct fluctuating wall shear stress measurements

Physical Review Fluids - Thu, 11/08/2018 - 10:00

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

Control of flow around a low Reynolds number airfoil using longitudinal strips

Physical Review Fluids - Wed, 11/07/2018 - 10:00

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

Axial and radial patterns of a bidispersed suspension in a fully filled horizontal rotating cylinder

Physical Review E - Tue, 11/06/2018 - 10:00

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

Lean premixed reacting flows with swirl and wall-separation zones in a contracting open circular chamber

Physical Review Fluids - Tue, 11/06/2018 - 10:00

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

Influence of interfacial elasticity on liquid entrainment in thin foam films

Physical Review Fluids - Tue, 11/06/2018 - 10:00

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

Temperature gradient induced double stabilization of the evaporation front within a drying porous medium

Physical Review Fluids - Tue, 11/06/2018 - 10:00

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

Dynamics of a thin film driven by a moving pressure source

Physical Review Fluids - Tue, 11/06/2018 - 10:00

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

Counterion flow through a deformable and charged nanochannel

Physical Review E - Thu, 11/01/2018 - 10:00

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

Particle collection by permeable drops

Physical Review Fluids - Thu, 11/01/2018 - 10:00

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

Three-dimensional instabilities and negative eddy viscosity in thin-layer flows

Physical Review Fluids - Thu, 11/01/2018 - 10:00

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

Local origin of mode-B secondary instability in the flow past a circular cylinder

Physical Review Fluids - Wed, 10/31/2018 - 10:00

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

Mesoscopic model for soft flowing systems with tunable viscosity ratio

Physical Review Fluids - Wed, 10/31/2018 - 10:00

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

Law of the wall for small-scale streamwise turbulence intensity in high-Reynolds-number turbulent boundary layers

Physical Review Fluids - Wed, 10/31/2018 - 10:00

Author(s): B. Ganapathisubramani

Following the dimensional analysis approach of previous works, a law-of-the-wall is proposed for small-scale fluctuations in turbulent wall-flow. Experimental data shows that this universal scaling law extends across almost the entire wall-layer and exhibits a logarithmic trend in the outer region.


[Phys. Rev. Fluids 3, 104607] Published Wed Oct 31, 2018

Deformation of a flexible fiber settling in a quiescent viscous fluid

Physical Review Fluids - Tue, 10/30/2018 - 10:00

Author(s): Benjamin Marchetti, Veronica Raspa, Anke Lindner, Olivia du Roure, Laurence Bergougnoux, Élisabeth Guazzelli, and Camille Duprat

A flexible fiber settling in a viscous fluid deforms and reorients to adopt eventually a more or less pronounced “U” shape, regardless of its initial configuration. Three different regimes depending on the relative magnitude of gravitational and elastic forces are identified.


[Phys. Rev. Fluids 3, 104102] Published Tue Oct 30, 2018

Slip-flow lattice-Boltzmann simulations in ducts and porous media: A full rehabilitation of spurious velocities

Physical Review E - Mon, 10/29/2018 - 10:00

Author(s): M. Aminpour, S. A. Galindo-Torres, A. Scheuermann, and L. Li

Slip flow in ducts and porous media is simulated using lattice-Boltzmann method incorporated with interfacial force models. The dependence of the results on the viscosity, LBM scheme (D3Q15 and D3Q19) and the relaxation time model (single- or multirelaxation time) is investigated. The severity of sp...


[Phys. Rev. E 98, 043110] Published Mon Oct 29, 2018

Pages

Subscribe to www.nonequilibrium-turbulence.org.uk aggregator - Latest papers in fluid mechanics