The coupling between turbulent flow physics and barchan dune geometry is important to dune migration, morphology of individual dunes, and the morphodynamics of merging and separating proximal dunes. Large-eddy simulation was used to model turbulent, inertial-dominated flow over a series of static ba...

[Phys. Rev. E 98, 033112] Published Tue Sep 18, 2018

]]>We consider freely decaying two-dimensional homogeneous and isotropic turbulent motion in a self-similar limit that is achieved at large Reynolds numbers based on time and the mean kinetic energy of the flow provided that initial average enstrophy tends to infinity as fluid viscosity tens to zero. I...

[Phys. Rev. E 98, 033110] Published Mon Sep 17, 2018

]]>Tenth-order compact difference code *Miranda* is used to perform large-eddy simulation (LES) of a hydrogen gas–plastic mixing layer in a spherical geometry. Once the mixing layer has achieved self-similar growth, it is heated to 1 keV, and the second-order arbitrary Lagrangian-Eulerian (ALE) code *Ares*...

[Phys. Rev. E 98, 033111] Published Mon Sep 17, 2018

]]>We examined the heat transfer of magnetothermal convection in a Rayleigh-Benard model (height 9.2 mm, vessel diameter 20 mm, aspect ratio 2.17). The working fluid was an aqueous gadolinium nitrate solution of 0.15 mol/kg ($\mathrm{pH}=4.52$ at 305.5 K, paramagnetic substance). Not only the magnetic body force ...

[Phys. Rev. E 98, 033109] Published Wed Sep 12, 2018

]]>The linear stability analysis of a fluid flow down a slippery inclined plane is carried out when the free surface of the fluid is contaminated by a monolayer of insoluble surfactant. The aim is to extend the earlier study [Samanta *et al.*, J. Fluid Mech. **684**, 353 (2011)] for low to high values of the...

[Phys. Rev. E 98, 033108] Published Fri Sep 07, 2018

]]>We report a nonlinear phenomenon discovered in the classical problem of thermal convection in rapidly rotating, self-gravitating, internally heated Boussinesq fluid spheres. When linear convective instability (the most unstable mode of convection) is in the form of an axially symmetric, equatorially...

[Phys. Rev. E 98, 031101(R)] Published Thu Sep 06, 2018

]]>Using laboratory experiments and simplified theoretical arguments, we show that the level of turbulence may reverse the direction of the mean lift on two- and three-dimensional structures with relatively short, deflected splitters. Planar particle image velocimetry and a high-resolution load cell we...

[Phys. Rev. E 98, 033106] Published Thu Sep 06, 2018

]]>Long-time simulations are conducted on a forced three-dimensional (3D) nonlinear viscous gravity-capillary wave equation that describes the surface wave pattern when the forcing moves on the surface of deep water with speeds less than the linear phase speed ${c}_{\mathrm{min}}=23\phantom{\rule{0.16em}{0ex}}\mathrm{cm}/\mathrm{s}$. Three different states are id...

[Phys. Rev. E 98, 033107] Published Thu Sep 06, 2018

]]>This study reports an opposing effect of curvature on the interfacial heat transfer, which implies a monotonic increase in the temperature jump over a convex surface and, conversely, a monotonic decrease in the temperature jump over a concave surface, as the curvature of the surface increases. The s...

[Phys. Rev. E 98, 033104] Published Wed Sep 05, 2018

]]>In this paper, we study the clap and fling motion of insect flights by applying an inviscid vortex shedding model. We describe separated vortices from the edges of two wings by vortex sheets and extend the model to the two bodies with symmetry. The model demonstrates sucking of leading edge vortices...

[Phys. Rev. E 98, 033105] Published Wed Sep 05, 2018

]]>A study of large-scale motions from a direct numerical simulation database of the turbulent boundary layer up to ${\text{Re}}_{\theta}\sim 2500$ is presented. The statistics of large-scale streamwise structures have been investigated using two-dimensional and three-dimensional (3D) extraction procedures. The large-scale s...

[Phys. Rev. E 98, 033101] Published Tue Sep 04, 2018

]]>The impulsively accelerated Richtmyer-Meshkov instability (RMI) of a fluid-solid interface is theoretically studied with a decomposition method, and the least stable mode is shown to oscillate but decay due to the combined effects of elasticity and viscosity. The dispersion relation of RMI in viscou...

[Phys. Rev. E 98, 033102] Published Tue Sep 04, 2018

]]>We ascertain the enhanced slip properties for a liquid flow over lubricant-infused unidirectional surfaces. This situation reflects many practical settings involving liquid flows past superhydrophobic grooves filled with gas, or past grooves infused with another, immiscible, liquid of smaller or equ...

[Phys. Rev. E 98, 033103] Published Tue Sep 04, 2018

]]>We infer both microscopic and macroscopic behaviors of a three-dimensional chaotic fluid flow using reservoir computing. In our procedure of the inference, we assume no prior knowledge of a physical process of a fluid flow except that its behavior is complex but deterministic. We present two ways of...

[Phys. Rev. E 98, 023111] Published Fri Aug 31, 2018

]]>Using direct numerical simulations, we study the statistical properties of reversals in two-dimensional Rayleigh-Bénard convection for infinite Prandtl number. We find that the large-scale circulation reverses irregularly, with the waiting time between two consecutive genuine reversals exhibiting a ...

[Phys. Rev. E 98, 023109] Published Wed Aug 29, 2018

]]>Point-vortex models are presented for the generalized Euler equations, which are characterized by a fractional Laplacian relation between the active scalar and the stream function. Special focus is given to the case of the surface quasigeostrophic (SQG) equations, for which the existence of finite-t...

[Phys. Rev. E 98, 023110] Published Wed Aug 29, 2018

]]>The artificial microswimmer is a cutting-edge technology with applications in drug delivery and micro-total-analysis systems. The flow field around a microswimmer can be regarded as Stokes flow, in which reciprocal body deformation cannot induce migration. In this study, we propose a microcapsule sw...

[Phys. Rev. E 98, 023108] Published Mon Aug 27, 2018

]]>This paper investigates the effect of inertia on the dynamics of elongated chains to go beyond the overdamped case that is often used to study such systems. For that purpose, numerical simulations are performed considering the motion of freely jointed bead-rod chains in an extensional flow in the pr...

[Phys. Rev. E 98, 023107] Published Fri Aug 24, 2018

]]>We compare different approaches towards an effective description of multiscale velocity field correlations in turbulence. Predictions made by the operator-product expansion, the so-called fusion rules, are placed in juxtaposition to an approach that interprets the turbulent energy cascade in terms o...

[Phys. Rev. E 98, 023104] Published Mon Aug 13, 2018

]]>Recent studies suggest that unstable, nonchaotic solutions of the Navier-Stokes equation may provide deep insights into fluid turbulence. In this article, we present a combined experimental and numerical study exploring the dynamical role of unstable equilibrium solutions and their invariant manifol...

[Phys. Rev. E 98, 023105] Published Mon Aug 13, 2018

]]>The effect of a soluble surfactant on the linear stability of layered two-phase Poiseuille flows through soft-gel-coated parallel walls is studied in this paper. The focus is on determining the effect of the elastohydrodynamic coupling between the fluids and the soft-gel layers on the various flow i...

[Phys. Rev. E 98, 023106] Published Mon Aug 13, 2018

]]>Reaction fronts described by the Kuramoto-Sivashinsky (KS) equation can exhibit complex behavior as they separate reacted from unreacted fluids. If the fluid of higher density is above a fluid of lower density, then the Rayleigh-Taylor instability can lead to fluid motion. In the reverse situation, ...

[Phys. Rev. E 98, 023102] Published Mon Aug 06, 2018

]]>A theoretical study on the electrophoresis of a soft particle made up of a charged hydrophobic inner core surrounded by polyelectrolyte layer (PEL) is made. The dielectric permittivity of the PEL and aqueous solution are considered to be different, which creates the ion partitioning effect. The ion ...

[Phys. Rev. E 98, 023103] Published Mon Aug 06, 2018

]]>We study the rotational dynamics of *inertial* disks and rods in three-dimensional, homogeneous, isotropic turbulence. In particular, we show how the alignment and the decorrelation timescales of such spheroids depend, critically, on both the level of inertia and the aspect ratio of these particles. T...

[Phys. Rev. E 98, 021101(R)] Published Fri Aug 03, 2018

]]>The atmosphere gains available potential energy by solar radiation and dissipates kinetic energy mainly in the atmospheric boundary layer. We analyze the fluctuations of the global mean energy cycle defined by Lorenz in a simulation with a simplified hydrostatic model. The energy current densities a...

[Phys. Rev. E 98, 023101] Published Fri Aug 03, 2018

]]>Steady thermocapillary droplet migration in a uniform temperature gradient combined with a radiation energy source at large Reynolds and Marangoni numbers is studied. To reach a terminal quasisteady process, the magnitude of the radiation energy source is required to preserve the conservative integr...

[Phys. Rev. E 98, 013110] Published Tue Jul 31, 2018

]]>Evaporation kinetics of pendant droplets is an area of immense importance in several applications, in addition to possessing rich fluid dynamics and thermal transport physics. This article experimentally and analytically sheds insight into the augmented evaporation dynamics of paramagnetic pendant d...

[Phys. Rev. E 98, 013109] Published Mon Jul 30, 2018

]]>A network-based analysis of a turbulent channel flow numerically solved at ${\text{Re}}_{\tau}=180$ is proposed as an innovative perspective for the spatial characterization of the flow field. Two spatial networks corresponding to the streamwise and wall-normal velocity components are built, where nodes represent po...

[Phys. Rev. E 98, 013107] Published Fri Jul 27, 2018

]]>The subject of the present theoretical study is the dynamics of a cavitation bubble in a spherical liquid-filled cavity surrounded by an infinite elastic solid. Two objectives are pursued. The first is to derive equations for the velocity and pressure fields throughout the liquid filling the cavity ...

[Phys. Rev. E 98, 013108] Published Fri Jul 27, 2018

]]>We study precessing turbulence, which appears in several geophysical and astrophysical systems, by direct numerical simulations of homogeneous turbulence where precessional instability is triggered due to the imposed background flow. We show that the time development of kinetic energy $\mathcal{K}$ occurs in tw...

[Phys. Rev. E 98, 011102(R)] Published Wed Jul 25, 2018

]]>We consider the situation of a large-scale stationary flow subjected to small-scale fluctuations. Assuming that the stable and unstable manifolds of the large-scale flow are known, we quantify the mean behavior and stochastic fluctuations of particles close to the unperturbed stable and unstable man...

[Phys. Rev. E 98, 013106] Published Tue Jul 24, 2018

]]>The classic self-similar solutions of the nonstationary compressible Euler equations obtained for a blast-wave propagation (Sedov, Taylor, and von Neumann), a shock-wave implosion (Guderley, Landau, and Stanyukovich), or an impulsive loading of a planar target (von Hoerner, Häfele, and Zel’dovich) h...

[Phys. Rev. E 98, 013105] Published Thu Jul 19, 2018

]]>Fingering instabilities of a miscible interface between two fluids in a gravitational field can develop due to adverse density gradients as in the well-known Rayleigh-Taylor (RT) and double-diffusive (DD) instabilities. In the absence of differential diffusion, the mixing rate and the onset time of ...

[Phys. Rev. E 98, 011101(R)] Published Tue Jul 17, 2018

]]>Flow in porous media is known to be largely affected by pore morphology. In this work, we investigate the effects of pore geometry on the transport and spatial correlations of flow through porous media in two distinct pore structures arising from three-dimensional assemblies of overlapping and nonov...

[Phys. Rev. E 98, 013104] Published Fri Jul 13, 2018

]]>At high temperatures, a droplet can rest on a cushion of its vapor (the Leidenfrost effect). Application of an electric field across the vapor gap fundamentally eliminates the Leidenfrost state by attracting liquid towards the surface. This study uses acoustic signature tracking to study electrostat...

[Phys. Rev. E 98, 013103] Published Thu Jul 12, 2018

]]>Droplet-solid interaction is a ubiquitous fluid phenomenon that underpins a wide range of applications. To further the understanding of this important problem, we use an axisymmetric lattice Boltzmann method (LBM) to model the droplet impact on a solid surface with different wettability. The method ...

[Phys. Rev. E 98, 013102] Published Mon Jul 09, 2018

]]>The wetting properties of immiscible two-phase systems are crucial in applications ranging from laboratory-on-a-chip devices to field-scale oil recovery. It has long been known that effective wetting properties can be altered by the application of an electric field; a phenomenon coined as electrowet...

[Phys. Rev. E 98, 013101] Published Thu Jul 05, 2018

]]>We study the thermoviscous fingering instability problem that develops when an injected fluid is displacing a fluid with different temperature and viscosity in a Hele-Shaw cell or porous medium. Using linear stability theory, we show how the thermal front caused by the different temperature of the i...

[Phys. Rev. E 97, 063112] Published Fri Jun 29, 2018

]]>A nested polyhedra model has been developed for magnetohydrodynamic turbulence. Driving only the velocity field at large scales with random, divergence-free forcing results in a clear, stationary ${k}^{-5/3}$ spectrum for both kinetic and magnetic energies. Since the model naturally effaces disparate scale...

[Phys. Rev. E 97, 063111] Published Tue Jun 26, 2018

]]>The effects of axial boundary conductivity on the formation and stability of a magnetized free Stewartson-Shercliff layer (SSL) in a short Taylor-Couette device are reported. As the axial field increases with insulating endcaps, hydrodynamic Kelvin-Helmholtz-type instabilities set in at the SSLs of ...

[Phys. Rev. E 97, 063110] Published Wed Jun 20, 2018

]]>In the previous studies of Rayleigh-Taylor instability, different methods were used to consider the effects of elasticity, viscosity, and magnetic fields. In this paper, a unified method, which was first used for fluids, is validated for different physical models, where the unstable mode is decompos...

[Phys. Rev. E 97, 063109] Published Tue Jun 19, 2018

]]>The angle of directional change of tracer trajectories in rotating Rayleigh-Bénard convection is studied as a function of the time increment $\tau $ between two instants of time along the trajectories, both experimentally and with direct numerical simulations. Our aim is to explore the geometrical charact...

[Phys. Rev. E 97, 063105] Published Mon Jun 18, 2018

]]>The present study focuses on the cross-stream migration of a neutrally buoyant two-dimensional drop in a Poiseuille flow in a channel under the influence of an electric field. In the absence of an electric field, the important nondimensional parameters describing this problem are the viscosity ratio...

[Phys. Rev. E 97, 063106] Published Mon Jun 18, 2018

]]>A networked-oscillator-based analysis is performed to examine and control the transfer of kinetic energy for periodic bluff body flows. The dynamics of energy fluctuations in the flow field are described by a set of oscillators defined by conjugate pairs of spatial proper orthogonal decomposition (P...

[Phys. Rev. E 97, 063107] Published Mon Jun 18, 2018

]]>We study average magnetic field growth in a mirror-symmetrical Kazantsev turbulent flow near the dissipative scales. Our main attention is directed to a subcritical regime, when an exponential decrease of magnetic energy is usually expected. We show that instead of damping, transient energy growth c...

[Phys. Rev. E 97, 063108] Published Mon Jun 18, 2018

]]>This paper reports the experimental results of a water droplet spreading on a glass substrate submerged in an oil phase. The radius of the wetted area grows exponentially over time forming two distinct regimes. The early time dynamics of wetting is characterized with the time exponent of 1, referred...

[Phys. Rev. E 97, 063104] Published Wed Jun 13, 2018

]]>A network community-based reduced-order model is developed to capture key interactions among coherent structures in high-dimensional unsteady vortical flows. The present approach is data-inspired and founded on network-theoretic techniques to identify important vortical communities that are comprise...

[Phys. Rev. E 97, 063103] Published Mon Jun 11, 2018

]]>When a more mobile fluid displaces another immiscible one in a porous medium, viscous fingering propagates with a partial sweep, which hinders oil recovery and soil remedy. We experimentally investigate the feasibility of tuning such fingering propagation in a nonuniform narrow passage with a radial...

[Phys. Rev. E 97, 061101(R)] Published Fri Jun 08, 2018

]]>This study provides sufficient conditions for the temporal monotonic decay of enstrophy for two-dimensional perturbations traveling in the incompressible, viscous, plane Poiseuille, and Couette flows. Extension of Synge's procedure [J. L. Synge, Proc. Fifth Int. Congress Appl. Mech. **2**, 326 (1938); S...

[Phys. Rev. E 97, 063102] Published Fri Jun 08, 2018

]]>Droplets on a surface immersed in oil are made to spread and retract by switching on and off a potential difference between the droplets and the surface. The authors find that the contact line friction depends on the viscosities of the droplet and the surrounding oil and that it does not depend significantly on the driving force or the direction of motion.

[Phys. Rev. E 97, 063101] Published Fri Jun 01, 2018

]]>In this paper, we study how the permeability of solid foam is modified by the presence of membranes that close partially or totally the cell windows connecting neighboring pores. The finite element method (FEM) simulations computing the Stokes problem are performed at both pore and macroscopic scale...

[Phys. Rev. E 97, 053111] Published Thu May 31, 2018

]]>In this study a single laser pulse spatially shaped into a ring is focused into a thin water layer, creating an annular cavitation bubble and cylindrical shock waves: an outer shock that diverges away from the excitation laser ring and an inner shock that focuses towards the center. A few nanosecond...

[Phys. Rev. E 97, 053112] Published Thu May 31, 2018

]]>Fluid motions in the inertial range of isotropic turbulence are fractal, with their space-filling capacity slightly below regular three-dimensional objects, which is a consequence of the energy cascade. Besides the energy cascade, the other often encountered cascading process is the momentum cascade...

[Phys. Rev. E 97, 053110] Published Tue May 29, 2018

]]>Molecular dynamics simulations are carried out to investigate the geometry effects of diatomic molecules on liquid flows in carbon nanotubes (CNTs). Oxygen molecules are considered as the fluid inside armchair ($n,n$) ($n=6\u201320$) CNTs. The simulated fluid temperature and bulk pressure for the liquid stat...

[Phys. Rev. E 97, 053109] Published Fri May 25, 2018

]]>Collision-coalescence growth of noninertial particles in three-dimensional homogeneous isotropic turbulence is studied. Smoluchowski's coagulation equation describes the evolution of the size distribution of particles in this system. By applying a methodology based on turbulence theory, the equation...

[Phys. Rev. E 97, 053108] Published Thu May 24, 2018

]]>The transition to the chaos of the air flow between two vertical plates maintained at different temperatures is studied in the Boussinesq approximation. After the first bifurcation at critical Rayleigh number ${\mathrm{Ra}}_{c}$, the flow consists of two-dimensional (2D) corotating rolls. The stability of the 2D ro...

[Phys. Rev. E 97, 053107] Published Tue May 22, 2018

]]>The present paper is devoted to studying the thermophoresis of a nonspherical convex particle suspended in a gas with nonuniform temperature distribution in the free-molecule regime. Based on the gas kinetic theory and the assumption of a rigid-body collision for the gas-particle interaction, analyt...

[Phys. Rev. E 97, 053106] Published Thu May 17, 2018

]]>Acoustophoresis is a form of contact-free particle manipulation in microfluidic devices. The precision of manipulation can be enhanced with better understanding of the acoustic radiation force. In this paper we present the measurements of interparticle radiation force between a pair of polystyrene b...

[Phys. Rev. E 97, 053105] Published Wed May 16, 2018

]]>On the basis of (i) particle image velocimetry data of a turbulent boundary layer with large field of view and good spatial resolution and (ii) a mathematical relation between the energy spectrum and specifically modeled flow structures, we show that the scalings of the streamwise energy spectrum ${E}_{\mathrm{1...}}$

[Phys. Rev. E 97, 053103] Published Mon May 14, 2018

]]>Pore-scale two-phase flow modeling is an important technology to study a rock's relative permeability behavior. To investigate if these models are predictive, the calculated pore-scale fluid distributions which determine the relative permeability need to be validated. In this work, we introduce a me...

[Phys. Rev. E 97, 053104] Published Mon May 14, 2018

]]>A series of laboratory experiments were performed to study the evolution of Peregrine breather (PB) in a wave flume in finite depth, and wave trains were initially generated in a region of quiescent water and then propagated into an adverse current region for which the current velocity strength grad...

[Phys. Rev. E 97, 053102] Published Mon May 07, 2018

]]>We examine the connection between the singularities or quasisingularities in the solutions of the incompressible Navier-Stokes equation (INSE) and the local energy transfer and dissipation, in order to explore in detail how the former contributes to the phenomenon of intermittency. We do so by analy...

[Phys. Rev. E 97, 053101] Published Thu May 03, 2018

]]>We use the Navier-Stokes-Fourier constitutive equations to study plane shock waves in dilute gases. It is shown that the experimental information on the normalized density profiles can be fit by using the so-called soft sphere model, in which the viscosity and thermal conductivity are proportional t...

[Phys. Rev. E 97, 043117] Published Mon Apr 30, 2018

]]>We build a general formalism to describe thin viscous jets as one-dimensional objects with an internal structure. We present in full generality the steps needed to describe the viscous jets around their central line, and we argue that the Taylor expansion of all fields around that line is convenient...

[Phys. Rev. E 97, 043115] Published Tue Apr 24, 2018

]]>In a companion paper [Phys. Rev. E **97**, 043115 (2018)], a formalism allowing to describe viscous fibers as one-dimensional objects was developed. We apply it to the special case of a viscous fluid torus. This allows to highlight the differences with the basic viscous string model and with its viscous...

[Phys. Rev. E 97, 043116] Published Tue Apr 24, 2018

]]>In low-permeability rock, fluid and mineral transport occur in pores and fracture apertures at the scale of micrometers and below. At this scale, the presence of surface charge, and a resultant electrical double layer, may considerably alter transport properties. However, due to the inherent nonline...

[Phys. Rev. E 97, 043114] Published Mon Apr 23, 2018

]]>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 $\mathrm{Si}{\mathrm{O}}_{2}$ spherical particles with different sizes were...

[Phys. Rev. E 97, 043113] Published Fri Apr 20, 2018

]]>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

]]>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

]]>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

]]>Linear stability analysis is conducted to study the onset of density-driven convection involved in solubility trapping of $\mathrm{C}{\mathrm{O}}_{2}$ 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

]]>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

]]>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

]]>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

]]>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

]]>The nonlinear oscillation of rarefied gas flow inside a two-dimensional rectangular cavity is investigated on the basis of the Shakhov kinetic equation. The gas dynamics, heat transfer, and damping force are studied numerically via the discrete unified gas-kinetic scheme for a wide range of paramete...

[Phys. Rev. E 97, 043103] Published Thu Apr 05, 2018

]]>We report evidence of variation in ion selectivity of a fabricated microchannel-nanochannel device resulting in the appearance of a distinct local maximum in the overlimiting chronopotentiometric response. In this system consisting of shallow microchannels joined by a nanochannel, viscous shear at t...

[Phys. Rev. E 97, 043104] Published Thu Apr 05, 2018

]]>We report on the generation of an intermittent wave field driven by a horizontally moving wave maker interacting with Faraday waves. The spectrum of the local gravitocapillary surface wave fluctuations displays a power law in frequency for a wide range of forcing parameters. We compute the probabili...

[Phys. Rev. E 97, 043101] Published Tue Apr 03, 2018

]]>The inertial locomotion of an elongated model swimmer in a Newtonian fluid is quantified, wherein self-propulsion is achieved via steady tangential surface treadmilling. The swimmer has a length $2l$ and a circular cross section of longitudinal profile $aR\left(z\right)$, where $a$ is the characteristic width of the...

[Phys. Rev. E 97, 043102] Published Tue Apr 03, 2018

]]>The coalescence, and subsequent satellite formation, of two inviscid droplets is studied numerically. The initial drops are taken to be of equal and different sizes, and simulations have been carried out with and without the presence of an electrical field. The main computational challenge is the tr...

[Phys. Rev. E 97, 033112] Published Fri Mar 30, 2018

]]>The torque in the Taylor-Couette flow for radius ratios $\eta \ge 0.97$, with smooth or grooved wall static outer cylinders, is studied experimentally, with the Reynolds number of the inner cylinder reaching up to ${\mathrm{Re}}_{\mathrm{i}}=2\times {10}^{5}$, corresponding to the Taylor number up to $\mathrm{Ta}=5\times {10}^{10}$. The grooves are perpendicular to...

[Phys. Rev. E 97, 033110] Published Mon Mar 26, 2018

]]>This paper presents an experimental study of front propagation in three-dimensional flows, showing evidence of one-way barriers that hinder the motion of the reaction fronts. In order to explain their results, the authors extend the burning-invariant-manifold theory to three dimensions, which enables them to capture the main features of the experimental results.

[Phys. Rev. E 97, 033111] Published Mon Mar 26, 2018

]]>Implicit large eddy simulations of two-dimensional Rayleigh-Taylor instability at different density ratios (i.e., Atwood number $A=0.05$, 0.5, and 0.9) are conducted to investigate the late-time dynamics of bubbles. To produce a flow field full of bounded, semibounded, and chaotic bubbles, three probl...

[Phys. Rev. E 97, 033108] Published Thu Mar 22, 2018

]]>Heavy particle clustering in turbulence is discussed from both phenomenological and analytical points of view, where the $-4/3$ power law of the pair-correlation function is obtained in the inertial range. A closure theory explains the power law in terms of the balance between turbulence mixing and pr...

[Phys. Rev. E 97, 033109] Published Thu Mar 22, 2018

]]>We investigate the nature of vapor bubble formation near a nanoscale-curved convex liquid-solid interface using two models: an equilibrium Gibbs model for homogenous nucleation, and a nonequilibrium dynamic van der Waals–diffuse-interface model for phase change in an initially cool liquid. Vapor bub...

[Phys. Rev. E 97, 033106] Published Mon Mar 19, 2018

]]>Secchi *et al.* [Nature (London) **537**, 210 (2016)] observed a large enhancement of the permeability and slip length in carbon nanotubes when the tube radius is of the order of 15 nm, but not in boron nitride nanotubes. It will be pointed out that none of the parameters that appear in the usual molecula...

[Phys. Rev. E 97, 033107] Published Mon Mar 19, 2018

]]>The slip of a fluid layer in contact with a solid confining surface is investigated for different temperatures and densities using molecular dynamic simulations. We show that for an anomalous waterlike fluid the slip goes as follows: for low levels of shear, defect slip appears and is related to the...

[Phys. Rev. E 97, 033104] Published Mon Mar 12, 2018

]]>Pseudopotential lattice Boltzmann methods (LBMs) can simulate a phase transition in high-density ratio multiphase flow systems. If coupled with thermal LBMs through equation of state, they can be used to study instantaneous phase transition phenomena with a high-temperature gradient where only one s...

[Phys. Rev. E 97, 033105] Published Mon Mar 12, 2018

]]>In this paper, a model for the radiation force exerted by standing surface acoustic waves (SSAWs) on a rigid cylinder in inviscid fluids is extended to account for the dependence on the Rayleigh angle. The conventional model for the radiation force used in the SSAW-based applications is developed in...

[Phys. Rev. E 97, 033103] Published Fri Mar 09, 2018

]]>We present an extensive numerical study of the time irreversibility of the dynamics of heavy inertial particles in three-dimensional, statistically homogeneous, and isotropic turbulent flows. We show that the probability density function (PDF) of the increment, $W\left(\tau \right)$, of a particle's energy over a ti...

[Phys. Rev. E 97, 033102] Published Fri Mar 02, 2018

]]>In this paper we consider the model of incompressible fluid described by the stochastic Navier-Stokes equation with finite correlation time of a random force. Inertial-range asymptotic behavior of fully developed turbulence is studied by means of the field theoretic renormalization group within the ...

[Phys. Rev. E 97, 033101] Published Thu Mar 01, 2018

]]>This paper reports on numerical investigations of the effect of a slight inclination $\alpha $ on pattern formation in a shallow vertical cylindrical cell heated from below for binary mixtures with a positive value of the Soret coefficient. By using direct numerical simulation of the three-dimensional Bouss...

[Phys. Rev. E 97, 023108] Published Mon Feb 26, 2018

]]>This paper presents a numerical and theoretical study of multistability in two stochastic models of transitional wall flows. An algorithm dedicated to the computation of rare events is adapted on these two stochastic models. The main focus is placed on a stochastic partial differential equation mode...

[Phys. Rev. E 97, 023109] Published Mon Feb 26, 2018

]]>We study the linear stability and nonlinear behavior of the electroconvection between two concentric half-cylinders with no-slip conditions on all boundaries. The no-slip condition makes impossible to apply the standard modal approach. Hence, we apply a finite element technique similar to the one we...

[Phys. Rev. E 97, 023106] Published Tue Feb 20, 2018

]]>Three-dimensional, compressible, magnetohydrodynamic turbulence of an isothermal, self-gravitating fluid is analyzed using two-point statistics in the asymptotic limit of large Reynolds numbers (both kinetic and magnetic). Following an alternative formulation proposed by Banerjee and Galtier [Phys. ...

[Phys. Rev. E 97, 023107] Published Tue Feb 20, 2018

]]>We use direct numerical simulations to calculate the joint probability density function of the relative distance $R$ and relative radial velocity component ${V}_{R}$ for a pair of heavy inertial particles suspended in homogeneous and isotropic turbulent flows. At small scales the distribution is scale invari...

[Phys. Rev. E 97, 023105] Published Thu Feb 15, 2018

]]>This paper is about the kinetic equation for gas-particle flows, in particular its well-posedness and realizability and its relationship to the generalized Langevin model (GLM) probability density function (PDF) equation. Previous analyses, e.g. [J.-P. Minier and C. Profeta, Phys. Rev. E **92**, 053020 ...

[Phys. Rev. E 97, 023104] Published Tue Feb 13, 2018

]]>The flow of a charged-stabilized suspension through a single constricted channel is studied experimentally by tracking the particles individually. Surprisingly, the behavior is found to be qualitatively similar to that of inertial dry granular systems: For small values of the neck-to-particle size r...

[Phys. Rev. E 97, 021102(R)] Published Wed Feb 07, 2018

]]>Ice nucleation is the crucial step for ice formation in atmospheric clouds and therefore underlies climatologically relevant precipitation and radiative properties. Progress has been made in understanding the roles of temperature, supersaturation, and material properties, but an explanation for the ...

[Phys. Rev. E 97, 023103] Published Tue Feb 06, 2018

]]>We use toroidal droplets to study the breakup dynamics of a Newtonian liquid jet in the presence of rheologically nonlinear materials. We find that the droplets resist breakup for times that are longer than those in the presence of Newtonian liquids. More importantly, we show that our experiments ca...

[Phys. Rev. E 97, 021101(R)] Published Mon Feb 05, 2018

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