# Physical Review Fluids

Recent articles in Physical Review Fluids
Updated: 1 day 9 hours ago

### In-phase synchronization between two auto-oscillating bubbles

Mon, 04/22/2019 - 11:00

Author(s): Dang Minh Nguyen, Muttikulangara Swaminathan Sanathanan, Jianmin Miao, David Fernandez Rivas, and Claus-Dieter Ohl

Two bubbles communicate with each other acoustically without being affected by any external sound field. We have performed an experiment showing that at the right distance, their connection becomes strong enough that they synchronize perfectly and eventually merge as one.

[Phys. Rev. Fluids 4, 043601] Published Mon Apr 22, 2019

### Comparing free surface and interface motion in electromagnetically driven thin-layer flows

Mon, 04/22/2019 - 11:00

Author(s): Benjamin C. Martell, Jeffrey Tithof, and Douglas H. Kelley

Particles at the top and bottom of a thin fluid layer are simultaneously tracked to measure how well such experiments model two-dimensional flow. Top and bottom flow directions align well. The bottom-to-top speed ratio nearly matches laminar predictions, even for chaotic flow, except in misaligned regions.

[Phys. Rev. Fluids 4, 043904] Published Mon Apr 22, 2019

### Dynamics of potential vorticity staircase evolution and step mergers in a reduced model of beta-plane turbulence

Mon, 04/22/2019 - 11:00

Author(s): M. A. Malkov and P. H. Diamond

Quasigeostrophic turbulence can self-organize into “staircases”—periodic arrays of turbulence separated by layers of potential vorticity (PV) gradients. These patterns are recovered from a reduced model that couples mean PV and potential enstrophy. Sharpening occurs due to bistable mixing of mean PV.

[Phys. Rev. Fluids 4, 044503] Published Mon Apr 22, 2019

### Harmonic to subharmonic transition of the Faraday instability in miscible fluids

Fri, 04/19/2019 - 11:00

Author(s): Antoine Briard, Benoît-Joseph Gréa, and Louis Gostiaux

Numerical simulations of the turbulent Faraday instability in miscible fluids reveal that when the mixing layer grows in size, there exists a highly anisotropic harmonic regime before the subharmonic one, in which background potential energy increases as a signature of irreversible mixing.

[Phys. Rev. Fluids 4, 044502] Published Fri Apr 19, 2019

### Dynamics of deformable straight and curved prolate capsules in simple shear flow

Thu, 04/18/2019 - 11:00

Author(s): Xiao Zhang, Wilbur A. Lam, and Michael D. Graham

A computational study of the motion of slightly deformable curved prolate capsules—a model for sickle red blood cells—in shear flow, shows that the average of the long-time orbit of the capsules, regardless of the initial orientation, can be well approximated using the Jeffery orbit solution.

[Phys. Rev. Fluids 4, 043103] Published Thu Apr 18, 2019

### Spirals and ribbons in counter-rotating Taylor-Couette flow: Frequencies from mean flows and heteroclinic orbits

Thu, 04/18/2019 - 11:00

Author(s): Yacine Bengana and Laurette S. Tuckerman

In simulations of counter-rotating Taylor-Couette flow, both spirals and ribbons are found to obey the RZIF property. We find two heteroclinic cycles, one whose excursions resemble ribbons, and the other which remains axisymmetric. Both cycles connect the same two stacked Taylor-vortex pairs.

[Phys. Rev. Fluids 4, 044402] Published Thu Apr 18, 2019

### Effect of shear on coherent structures in turbulent convection

Wed, 04/17/2019 - 11:00

Author(s): Prafulla P. Shevkar, G. S. Gunasegarane, Sanal K. Mohanan, and Baburaj A. Puthenveettil

In the presence of shear, the mean spacing between coherent structures on horizontal surfaces in turbulent Rayleigh-Bénard convection, in excess of the no-shear spacing, is shown to be proportional to Re3Zsh/(DRa), where Zsh is the viscous-shear length and D a nonmonotonic function of Pr.

[Phys. Rev. Fluids 4, 043502] Published Wed Apr 17, 2019

### Are extreme dissipation events predictable in turbulent fluid flows?

Wed, 04/17/2019 - 11:00

Author(s): Patrick J. Blonigan, Mohammad Farazmand, and Themistoklis P. Sapsis

A method that combines dynamics and statistics for the underlying attractor allows for the extraction of characteristic states that precede laminarization events which subsequently lead to extreme dissipation episodes.

[Phys. Rev. Fluids 4, 044606] Published Wed Apr 17, 2019

### Self-acceleration and global pulsation in expanding laminar ${\mathrm{H}}_{2}\text{−}{\mathrm{O}}_{2}\text{−}{\mathrm{N}}_{2}$ flames

Tue, 04/16/2019 - 11:00

Author(s): Jialong Huo, Abhishek Saha, Tao Shu, Zhuyin Ren, and Chung K. Law

Self-acceleration and global pulsation of spherically expanding hydrogen-air flames, with the pulsation arising from the growing and splitting of cellular structures due to flame instability, is studied.

[Phys. Rev. Fluids 4, 043201] Published Tue Apr 16, 2019

### Numerical study of thermal convection induced by centrifugal buoyancy in a rotating cylindrical annulus

Tue, 04/16/2019 - 11:00

Author(s): Changwoo Kang, Antoine Meyer, Harunori N. Yoshikawa, and Innocent Mutabazi

An investigation shows that thermal convection due to centrifugal buoyancy in a cylindrical annulus occurs in the form of drifting columnar vortices. For Rayleigh number Ra > 105, the Coriolis buoyancy deforms the columns and thermal plumes.

[Phys. Rev. Fluids 4, 043501] Published Tue Apr 16, 2019

### Extreme nonequilibrium electrophoresis of an ion-selective microgranule

Tue, 04/16/2019 - 11:00

Author(s): G. S. Ganchenko, E. A. Frants, V. S. Shelistov, N. V. Nikitin, S. Amiroudine, and E. A. Demekhin

We develop a semi-analytic approach to the electrophoresis of an ion-selective particle and show that it compares well to direct numerical simulations and experimental data. A nested concentration profile and a scaling of the the electrophoretic velocity with electric field are found.

[Phys. Rev. Fluids 4, 043703] Published Tue Apr 16, 2019

### Direct numerical simulations of liquid films in two dimensions under horizontal and vertical external vibrations

Tue, 04/16/2019 - 11:00

Author(s): Sebastian Richter and Michael Bestehorn

A liquid film on a horizontally oscillating solid substrate is studied numerically. Breakup of the film is observed as well as formation and coarsening of isolated drops. For oscillations that violate mirror symmetry in the horizontal direction, a mean flow occurs, and the drops begin to move laterally.

[Phys. Rev. Fluids 4, 044004] Published Tue Apr 16, 2019

### Electrostatic assist of liquid transfer between plates and cavities

Tue, 04/16/2019 - 11:00

Author(s): Chung-Hsuan Huang, Marcio S. Carvalho, and Satish Kumar

Liquid removal from cavities is a major challenge in industrial printing processes. It is shown that applying an electric field causes the contact line on the cavity wall to slip. The effect is more pronounced for a deep cavity, resulting in a larger percentage of liquid transferred compared to a shallow cavity.

[Phys. Rev. Fluids 4, 044005] Published Tue Apr 16, 2019

### Flow in a containerless liquid system: Ring-sheared drop with finite surface shear viscosity

Tue, 04/16/2019 - 11:00

Author(s): Shreyash Gulati, Frank P. Riley, Amir H. Hirsa, and Juan M. Lopez

In microgravity a stationary contact ring can constrain a large liquid drop and a second contact ring in rotation can impose shear. With numerical simulations we show that significant flow occurs for finite surface interfacial viscosity, as for example, when protein is adsorbed to the interface.

[Phys. Rev. Fluids 4, 044006] Published Tue Apr 16, 2019

### Analysis of the early stages of liquid-water-drop explosion by numerical simulation

Mon, 04/15/2019 - 11:00

Author(s): Thomas Paula, Stefan Adami, and Nikolaus A. Adams

A level-set-based conservative interface-interaction method is extended for phase transition and cavity formation to study the shock-driven explosion of liquid-water microdrops numerically. Comparison with experimental results shows good agreement for the initial stages of the drop dynamics.

[Phys. Rev. Fluids 4, 044003] Published Mon Apr 15, 2019

### Diffusiophoretic and diffusioosmotic velocities for mixtures of valence-asymmetric electrolytes

Fri, 04/12/2019 - 11:00

Author(s): Ankur Gupta, Bhargav Rallabandi, and Howard A. Stone

The diffusioosmotic slip velocity due to an applied concentration gradient of the ions in the bulk is predicted for a mixture of valence-asymmetric electrolytes at arbitrary zeta potentials in the limit of a thin double layer.

[Phys. Rev. Fluids 4, 043702] Published Fri Apr 12, 2019

### Intense sound radiation by high-speed flow: Turbulence structure, gas properties, and near-field gas dynamics

Thu, 04/11/2019 - 11:00

Author(s): David A. Buchta and Jonathan B. Freund

Weak near-field nonlinearities explain key features of the intense sound radiated by high-speed turbulence. The sound-field wave structure, pressure skewness, and pressure intensity are also shown to be relatively insensitive to the large-scale turbulence structure.

[Phys. Rev. Fluids 4, 044605] Published Thu Apr 11, 2019

### Generation of high-intensity ultrasound through shock propagation in liquid jets

Wed, 04/10/2019 - 11:00

Author(s): Gabriel Blaj, Mengning Liang, Andrew L. Aquila, Philip R. Willmott, Jason E. Koglin, Raymond G. Sierra, Joseph S. Robinson, Sébastien Boutet, and Claudiu A. Stan

An investigation shows how single shock waves, produced in water jets by x-ray laser pulses, propagate and become ultrasonic shock trains through oblique shock reflections and cavitation. These trains are one of the loudest sounds ever made in liquid water and may damage samples studied with x-ray lasers.

[Phys. Rev. Fluids 4, 043401] Published Wed Apr 10, 2019

### Faraday instability in double-interface fluid layers

Wed, 04/10/2019 - 11:00

Author(s): Kevin Ward, Farzam Zoueshtiagh, and Ranga Narayanan

Three-fluid systems subjected to periodic mechanical oscillations are theoretically and experimentally examined. The addition of the third fluid can trigger both stabilizing or destabilizing effects on the interfaces, and additional codimension points are obtainable.

[Phys. Rev. Fluids 4, 043903] Published Wed Apr 10, 2019

### Molecular dynamics study of the translation and rotation of amphiphilic Janus nanoparticles at a vapor-liquid surface

Wed, 04/10/2019 - 11:00

Author(s): Joel Koplik and Charles Maldarelli

The equilibrium contact angle of a heterogeneous colloidal particle at a liquid/vapor interface varies with position and may have distinct local equilibria at different orientations. We show that the free energy determines a particle’s orientation as a function of orientation and immersion depth.

[Phys. Rev. Fluids 4, 044201] Published Wed Apr 10, 2019