Latest papers in fluid mechanics
Discontinuous contact line motion of evaporating particle-laden droplet on superhydrophobic surfaces
Author(s): Yutaka Yamada and Akihiko Horibe
The three-phase contact line motion on a superhydrophobic surface through particle-laden sessile droplet evaporation was investigated. Sample surfaces with micro- and nanoscale structures were generated by various durations of chemical treatment and SiO2 spherical particles with different sizes were...
[Phys. Rev. E 97, 043113] Published Fri Apr 20, 2018
Thermal convection of liquid sodium in inclined cylinders
Author(s): Ruslan Khalilov, Ilya Kolesnichenko, Alexander Pavlinov, Andrey Mamykin, Alexander Shestakov, and Peter Frick
The effect of inclination on the sodium (Pr=0.0094) turbulent convection in a cylinder of unit aspect ratio was studied experimentally for a fixed Rayleigh number Ra=(1.47±0.03)×107, and the inclination angle varied from 0° (the Rayleigh-Benard convection) up to 90° with a step of 10°.
[Phys. Rev. Fluids 3, 043503] Published Fri Apr 20, 2018
Experimental and numerical investigation of electrohydrodynamic flow in a point-to-ring corona discharge
Author(s): Yifei Guan, Ravi Sankar Vaddi, Alberto Aliseda, and Igor Novosselov
An electrohydrodynamic flow in a point-to-ring corona configuration is investigated experimentally and numerically. A parameter X, defined as the ratio of the local electric force to the inertial term, characterizes the effect of electrohydrodynamic forcing on bulk flow.
[Phys. Rev. Fluids 3, 043701] Published Fri Apr 20, 2018
Appearance of deterministic mixing behavior from ensembles of fluctuating hydrodynamics simulations of the Richtmyer-Meshkov instability
Author(s): Kiran Narayanan and Ravi Samtaney
We obtain numerical solutions of the two-fluid fluctuating compressible Navier-Stokes (FCNS) equations, which consistently account for thermal fluctuations from meso- to macroscales, in order to study the effect of such fluctuations on the mixing behavior in the Richtmyer-Meshkov instability (RMI). ...
[Phys. Rev. E 97, 043111] Published Thu Apr 19, 2018
Dynamics of deformation and pinch-off of a migrating compound droplet in a tube
Author(s): Manash Pratim Borthakur, Gautam Biswas, and Dipankar Bandyopadhyay
A computational fluid dynamic investigation has been carried out to study the dynamics of a moving compound droplet inside a tube. The motions associated with such a droplet is uncovered by solving the axisymmetric Navier-Stokes equations in which the spatiotemporal evolution of a pair of twin-defor...
[Phys. Rev. E 97, 043112] Published Thu Apr 19, 2018
Minimal formulation of the linear spatial analysis of capillary jets: Validity of the two-mode approach
Author(s): H. González, P. A. Vazquez, F. J. García, and J. Guerrero
Linear models are often used for the evolution of capillary jets. Here we present the simplest linear spatial formulation and compare it to numerical simulations. Two magnitudes, shape deformation, and mean axial velocity, and two spatial modes are needed, with one of them decaying exponentially.
[Phys. Rev. Fluids 3, 044802] Published Wed Apr 18, 2018
Soap-film flow induced by electric fields in asymmetric frames
Author(s): S. Mollaei, M. Nasiri, N. Soltanmohammadi, R. Shirsavar, A. Ramos, and A. Amjadi
Net fluid flow of soap films induced by (ac or dc) electric fields in asymmetric frames is presented. Previous experiments of controllable soap film flow required the simultaneous use of an electrical current passing through the film and an external electric field or the use of nonuniform ac electri...
[Phys. Rev. E 97, 043110] Published Tue Apr 17, 2018
Fingering patterns in magnetic fluids: Perturbative solutions and the stability of exact stationary shapes
Author(s): Pedro H. A. Anjos, Sérgio A. Lira, and José A. Miranda
Pattern formation processes in magnetic fluids confined in a Hele-Shaw cell and subjected to a radial magnetic field are studied. It is shown that the weakly nonlinear flow drives an initially circular interface towards nontrivial exact stationary shapes, which are dynamically stable.
[Phys. Rev. Fluids 3, 044002] Published Tue Apr 17, 2018
Numerical simulations of thermal convection on a hemisphere
Author(s): C.-H. Bruneau, P. Fischer, Y.-L. Xiong, and H. Kellay (Cyclobulle Collaboration)
Original numerical simulations of 2D turbulent convection on a hemisphere are presented. Nusselt and Reynolds numbers verify scaling laws consistent with Rayleigh-Bénard convection. Despite significant differences in geometry with classical 3D cells, the scaling laws of thermal convection are robust.
[Phys. Rev. Fluids 3, 043502] Published Mon Apr 16, 2018
Spheroidal and conical shapes of ferrofluid-filled capsules in magnetic fields
Author(s): Christian Wischnewski and Jan Kierfeld
The numerical and analytical investigation of elastic capsules filled with a ferrofluid/dielectric liquid in a uniform magnetic/electric field shows a discontinuous spherical-to-conical shape transition for increasing fields with diverging strains in the conical tips.
[Phys. Rev. Fluids 3, 043603] Published Mon Apr 16, 2018
Instability-driven frequency decoupling between structure dynamics and wake fluctuations
Author(s): Yaqing Jin, Jin-Tae Kim, and Leonardo P. Chamorro
The interaction between wall-mounted, flexible plates and wake fluctuations is experimentally investigated as a function of several geometrical and flow parameters. It is demonstrated that significant decoupling between the dynamics of the structures and flow may occur because of near-wake flow instability.
[Phys. Rev. Fluids 3, 044701] Published Fri Apr 13, 2018
Onset of density-driven instabilities in fractured aquifers
Author(s): Seyed Mostafa Jafari Raad and Hassan Hassanzadeh
Linear stability analysis is conducted to study the onset of density-driven convection involved in solubility trapping of CO2 in fractured aquifers. The effect of physical properties of a fracture network on the stability of a diffusive boundary layer in a saturated fractured porous media is investi...
[Phys. Rev. E 97, 043109] Published Thu Apr 12, 2018
Topology of two-dimensional turbulent flows of dust and gas
Author(s): Dhrubaditya Mitra and Prasad Perlekar
In a study of inertial particle velocity gradients and the corresponding flow topology, the density weighted joint distribution shows that converging saddle structures are most probable.
[Phys. Rev. Fluids 3, 044303] Published Thu Apr 12, 2018
Effect of shock waves on the statistics and scaling in compressible isotropic turbulence
Author(s): Jianchun Wang, Minping Wan, Song Chen, Chenyue Xie, and Shiyi Chen
This paper examines the spectra of the velocity and several thermodynamic variables in compressible turbulence in the presence of large-scale shock waves. The authors perform simulations of turbulence driven by solenoidal and compressible forces for a range of Mach numbers, and are able to extract different scaling behaviors. In addition, they propose heuristic ways to account for the observations.
[Phys. Rev. E 97, 043108] Published Wed Apr 11, 2018
Multiscale analysis of the invariants of the velocity gradient tensor in isotropic turbulence
Author(s): Mohammad Danish and Charles Meneveau
A detailed study on the scale dependence of various quantities of interest, such as the population fraction of different flow-topologies, is presented. While the quantities appear close to scale invariant in inertial range, a “bump” is observed at length scales between the inertial and viscous ranges.
[Phys. Rev. Fluids 3, 044604] Published Wed Apr 11, 2018
Marangoni instability in a thin film heated from below: Effect of nonmonotonic dependence of surface tension on temperature
Author(s): Rajkumar Sarma and Pranab Kumar Mondal
We investigate Marangoni instability in a thin liquid film resting on a substrate of low thermal conductivity and separated from the surrounding gas phase by a deformable free surface. Considering a nonmonotonic variation of surface tension with temperature, here we analytically derive the neutral s...
[Phys. Rev. E 97, 043105] Published Mon Apr 09, 2018
Linear Rayleigh-Taylor instability in an accelerated Newtonian fluid with finite width
Author(s): S. A. Piriz, A. R. Piriz, and N. A. Tahir
The linear theory of Rayleigh-Taylor instability is developed for the case of a viscous fluid layer accelerated by a semi-infinite viscous fluid, considering that the top interface is a free surface. Effects of the surface tensions at both interfaces are taken into account. When viscous effects domi...
[Phys. Rev. E 97, 043106] Published Mon Apr 09, 2018
Electrically modulated capillary filling imbibition of nematic liquid crystals
Author(s): Jayabrata Dhar and Suman Chakraborty
The flow of nematic liquid crystals (NLCs) in the presence of an electric field is typically characterized by the variation in its rheological properties due to transition in its molecular arrangements. Here, we bring out a nontrivial interplay of a consequent alteration in the resistive viscous eff...
[Phys. Rev. E 97, 043107] Published Mon Apr 09, 2018
Simulations of sheared dense noncolloidal suspensions: Evaluation of the role of long-range hydrodynamics
Author(s): Stany Gallier, François Peters, and Laurent Lobry
We find that the consequence of switching off long-range hydrodynamic interactions in simulations of concentrated suspension is that they can be switched off if considering the viscosity, but not if considering the diffusivity or particle velocities.
[Phys. Rev. Fluids 3, 042301(R)] Published Mon Apr 09, 2018
Unsteady sedimentation of a sphere in wormlike micellar fluids
Author(s): Yiran Zhang and Susan J. Muller
Flow transitions in the settling of a sphere in non-shear-banding wormlike micelle solutions are mapped. The onset of unsteady sedimentation correlates with an extensional Deborah number, while the velocity fluctuations are related to a shear Deborah number and an elastic Mach number.
[Phys. Rev. Fluids 3, 043301] Published Mon Apr 09, 2018
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