Electrohydrodynamic (EHD) breakup phenomena for a leaky dielectric drop suspended in another immiscible viscous dielectric and subjected to a uniform electric field are examined using the leaky dielectric theory and the explicit forcing lattice Boltzmann method, by taking into account full nonlinear...

[Phys. Rev. E 99, 043106] Published Thu Apr 18, 2019

]]>In this paper the small-amplitude motion of multiple superposed viscous fluids is studied as a linearized initial-value problem. The analysis results in a closed set of equations for the Laplace transformed amplitudes of the interfaces that can be inverted numerically. The derived equations also con...

[Phys. Rev. E 99, 043104] Published Tue Apr 16, 2019

]]>We study the contact-angle hysteresis and morphology changes of a liquid drop sitting on a solid substrate inclined with respect to the horizontal at an angle $\alpha $. This one is always smaller than the critical angle, ${\alpha}_{\text{crit}}$, above which the drop would start to slide down. The hysteresis cycle is perform...

[Phys. Rev. E 99, 043105] Published Tue Apr 16, 2019

]]>Experimental observations of the growth and collapse of acoustically and laser-nucleated single bubbles in water and agarose gels of varying stiffness are presented. The maximum radii of generated bubbles decreased as the stiffness of the media increased for both nucleation modalities, but the maxim...

[Phys. Rev. E 99, 043103] Published Wed Apr 10, 2019

]]>Pumping a viscous fluid underneath an elastic sheet will cause the sheet to bulge upward. The liquid pressure is balanced by the sheet’s elasticity as well as gravity. The authors’ experiment shows reasonable agreement with two different theories, and may provide a model for the formation of magma intrusions between layers of rock.

[Phys. Rev. E 99, 043102] Published Thu Apr 04, 2019

]]>We study the dynamics of a thin liquid film on a compliant substrate in the presence of thermocapillary effect. A set of long-wave equations are derived to investigate the effects of fluid gravity $\left(G\right)$, fluid inertia (Re), and Marangoni stresses (Ma) on the dynamics of the liquid film and the complia...

[Phys. Rev. E 99, 043101] Published Tue Apr 02, 2019

]]>Liquid Sn droplets were irradiated with shaped bursts of picosecond laser pulses. The shapes of the deforming droplets following the impact of the recoil pressure induced by these bursts were imaged using a high-speed shadowgraph system. The rupture time ${\stackrel{\u0303}{t}}_{b}$ of the droplet expanding as a thin fluid ...

[Phys. Rev. E 99, 031102(R)] Published Fri Mar 29, 2019

]]>Large-eddy simulations of thermal convection are presented and discussed for a cube with rough horizontal surfaces. Two types of roughness are considered: uniformly placed pyramids, and grooves aligned parallel to one set of sidewalls. The Rayleigh number is ${10}^{8}$, the Prandtl number 0.7, and the aspe...

[Phys. Rev. E 99, 033116] Published Thu Mar 28, 2019

]]>Inflation refers to the exponential expansion of the early universe that can explain many of the properties we see today. The authors of this work propose an experimental analog in which the interface between two immiscible, magnetic fluids shows inflationary behavior. The work shows that waves created at the interface could reproduce known solutions of inflationary models, and suggests a variety of other cosmological scenarios that could be simulated.

[Phys. Rev. E 99, 031101(R)] Published Wed Mar 27, 2019

]]>Direct numerical simulations of three-dimensional compressible helical turbulence are carried out at a grid resolution of ${1024}^{3}$ to investigate the effect of pressure, which is important for the joint cascade of kinetic energy and helicity in compressible helical turbulence. The principal finding is ...

[Phys. Rev. E 99, 033114] Published Wed Mar 27, 2019

]]>Faraday waves are a classic example of a system in which an extended pattern emerges under spatially uniform forcing. Motivated by systems in which uniform excitation is not plausible, we study both experimentally and theoretically the effect of heterogeneous forcing on Faraday waves. Our experiment...

[Phys. Rev. E 99, 033115] Published Wed Mar 27, 2019

]]>We develop a numerical model for a two-phase flow of a pair of immiscible liquids within a capillary tube. We assume that a capillary is initially saturated with one liquid and the other liquid is injected via one of the capillary's ends. The governing equations are solved in the velocity-pressure f...

[Phys. Rev. E 99, 033113] Published Thu Mar 21, 2019

]]>Near the thermodynamic critical point, the physical properties of binary fluids exhibit large variations in response to small temperature and concentration differences, whose effects on the onset of double-diffusive convection are reported here. The vertical symmetry is broken, irregular penetrative...

[Phys. Rev. E 99, 033112] Published Mon Mar 18, 2019

]]>It is well known that the turbulence that evolves from the tangles of vortices in quantum fluids at scales larger than the typical quantized vortex spacing $\ell $ has a close resemblance with classical turbulence. The temperature-dependent mutual friction parameter $\alpha \left(T\right)$ drives the turbulent statistics in...

[Phys. Rev. E 99, 033111] Published Wed Mar 13, 2019

]]>In this paper we use simulations of the magnetohydrodynamic equations coupled with heat to show the generation of magnetic field by the dynamical interaction of a pair of vortices in a fluid electrically conducting within a cylindrical domain nonhomogeneously heated from below, setting in a rotation...

[Phys. Rev. E 99, 033109] Published Mon Mar 11, 2019

]]>The dynamics of Rayleigh-Taylor turbulence convection in the presence of an alternating, time-periodic acceleration is studied by means of extensive direct numerical simulations of the Boussinesq equations. Within this framework, we discover a mechanism of relaminarization of turbulence: the alterna...

[Phys. Rev. E 99, 033110] Published Mon Mar 11, 2019

]]>Stand-alone and portable lab-on-chips (LOC) can be obtained by exploiting capillary flow in porous media. Polymethylmethacrylate (PMMA) platforms obtained through powder-based three-dimensional (3D) printing are appropriate for capillarity-driven LOCs. However, fluid flow in such platforms needs to ...

[Phys. Rev. E 99, 033107] Published Thu Mar 07, 2019

]]>We investigate the effects of the Péclet number (Pe) on transport of an inert chemical tracer in heterogeneous porous media. We simulate fluid flow and transport through two-dimensional pore-scale matrices with varying structural complexity. With increasing Pe, the anomalous nature of the transport ...

[Phys. Rev. E 99, 033108] Published Thu Mar 07, 2019

]]>Unlike the traditionally reported Leidenfrost droplet which only floats on a thin film of vapor, we observe a prominent jump of the impinged droplets in the transition from the contact boiling to the Leidenfrost state. The vapor generation between the droplet and the substrate is vigorous enough to ...

[Phys. Rev. E 99, 033106] Published Tue Mar 05, 2019

]]>We draw attention to recent high-explosive (HE) experiments which provide compression of macroscopic amount of matter to high, even record, values of pressure in comparison with other HE experiments. The observed bounce after the compression corresponds to processes in core-collapse supernova explos...

[Phys. Rev. E 99, 033102] Published Mon Mar 04, 2019

]]>This work explores the stability and hysteresis effects that occur when a small sink of momentum is introduced into a heat-driven, two-dimensional convective flow. As per standard fluid mechanical intuition, the system minimizes work generation and dissipation when one component of momentum is extra...

[Phys. Rev. E 99, 033103] Published Mon Mar 04, 2019

]]>We study the onset of intermittency in stochastic Burgers hydrodynamics, as characterized by the statistical behavior of negative velocity gradient fluctuations. The analysis is based on the response functional formalism, where specific velocity configurations—the *viscous instantons*—are assumed to p...

[Phys. Rev. E 99, 033104] Published Mon Mar 04, 2019

]]>We present results of laboratory experiments on the formation, evolution, and wavelength selection of vortex ripples. These ripples formed on a sediment bed at the bottom of a water-filled oscillating cylindrical tank mounted on top of a rotating table. The table is made to oscillate sinusoidally in...

[Phys. Rev. E 99, 033105] Published Mon Mar 04, 2019

]]>In this work we analyze the velocity of a swimming sheet near a plane surfactant-laden interface by assuming the Reynolds number and the sheet's deformation to be small. We observe a nonmonotonic dependence of the sheet's velocity on the Marangoni number $\left(\text{Ma}\right)$ and the surface Péclet number $\left({\text{Pe}}_{s}\right)$. For...

[Phys. Rev. E 99, 033101] Published Fri Mar 01, 2019

]]>In this work we present a phenomenological model to look for a better understanding of the shock-wave structure in dilute monatomic gases. The model is based on the principles of linear irreversible thermodynamics, where we have been aware of the flow anisotropy caused by the shock-wave propagation....

[Phys. Rev. E 99, 023114] Published Wed Feb 27, 2019

]]>We analyze the effect of a small inclination on the well-studied problem of two-dimensional binary fluid convection in a horizontally extended closed rectangular box with a negative separation ratio, heated from below. The horizontal component of gravity generates a shear flow that replaces the moti...

[Phys. Rev. E 99, 023113] Published Tue Feb 26, 2019

]]>We consider Rayleigh-Taylor and Richtmyer-Meshkov instabilities at the interface between two fluids, one or both of which may be viscous. We derive exact analytic expressions for the amplitude $\eta \left(t\right)$ in the linear regime when only one of the fluids is viscous. The more general case is solved numerical...

[Phys. Rev. E 99, 023112] Published Mon Feb 25, 2019

]]>The cylindrical wall boundary layer of a closed cylinder split in two halves at the equator is studied experimentally. When these two parts rotate in exact corotation the internal flow is essentially in solid-body rotation at the angular velocity of both halves. When a slight difference between the ...

[Phys. Rev. E 99, 023111] Published Tue Feb 19, 2019

]]>The subject of the present theoretical study is the dynamics of bubble-bubble interactions in a viscoelastic medium. First, new equations for calculating the viscoelastic drag exerted on bubbles during their translational motion in a viscoelastic medium are derived. The drag equations are incorporat...

[Phys. Rev. E 99, 023109] Published Thu Feb 14, 2019

]]>We report an experimental observation of rotating depression soliton sets on the inner surface of a viscous liquid ring, carrying background waves. These occur within a rotating shallow layer of oil inside a stationary cylindrical container. The solitons are organized either in single, two, or regul...

[Phys. Rev. E 99, 023110] Published Thu Feb 14, 2019

]]>We report on experiments and modeling on a rotating confined liquid that is forced by circumferential jets coaxial with the rotation axis, wherein system-scale secondary flows are observed to emerge. The jets are evenly divided in number between inlets and outlets and have zero net mass transport. F...

[Phys. Rev. E 99, 023108] Published Tue Feb 12, 2019

]]>Large-scale coherent structures emerging in two-dimensional flows can be predicted from statistical physics inspired methods consisting in minimizing the global enstrophy while conserving the total energy and circulation in the Euler equations. In many situations, solid obstacles inside the domain m...

[Phys. Rev. E 99, 023105] Published Mon Feb 11, 2019

]]>A shear flow of liquid metal (Galinstan) is driven in an annular channel by counter-rotating traveling magnetic fields imposed at the end caps. When the traveling velocities are large, the flow is turbulent and its azimuthal component displays random reversals. Power spectra of the velocity field ex...

[Phys. Rev. E 99, 023106] Published Mon Feb 11, 2019

]]>The dynamics of a nonspherical droplet falling in air is investigated via three-dimensional numerical simulations of the Navier-Stokes and continuity equations. The main focus of this work is to study the effects of the relative influence of surface tension force over the inertial force and the orie...

[Phys. Rev. E 99, 023107] Published Mon Feb 11, 2019

]]>Fluid transport in porous materials is commonly studied in geological samples (soil, sediments, etc.) or idealized systems, but the fluid flow through compacted granular materials, consisting of substantially strained granules, remains relatively unexplored. As a step toward filling this gap, we stu...

[Phys. Rev. E 99, 023103] Published Fri Feb 08, 2019

]]>The interactions of bacteria with surfaces have important implications in numerous areas of research, such as bioenergy, biofilm, biofouling, and infection. Recently, several experimental studies have reported that the adhesion of bacteria can be reduced considerably by microscale wall features. To ...

[Phys. Rev. E 99, 023104] Published Fri Feb 08, 2019

]]>The dynamic characteristics of a two-dimensional deformable capsule in a simple shear flow are studied with an immersed boundary-lattice Boltzmann method. Simulations are conducted by varying the Reynolds number (Re) from 0.0125 to 2000 and the dimensionless shear rate ($G$) from 0.001 to 0.5. The $G$-R...

[Phys. Rev. E 99, 023101] Published Thu Feb 07, 2019

]]>Small-scale characteristics of turbulence such as velocity gradients and vorticity fluctuate rapidly in magnitude and oscillate in sign. Much work exists on the characterization of magnitude variations, but far less on sign oscillations. While in homogeneous turbulence averages performed on large sc...

[Phys. Rev. E 99, 023102] Published Thu Feb 07, 2019

]]>Generation of homogeneous isotropic turbulence was attempted using an innovative “multifan wind tunnel” with 99 fans installed. The driving method used is based on a principle that the shear layers generated between outflows from the adjacent ducts lead to turbulent flow downstream. First, a signal ...

[Phys. Rev. E 99, 013112] Published Wed Jan 30, 2019

]]>We report Stokesian dynamics simulations of bidensity suspensions rotating in a horizontal cylinder. We studied the phase space and radial and axial patterns in settling as well as floating systems. Each system was composed of particle mixtures of two different densities. As many as eight unique pha...

[Phys. Rev. E 99, 013111] Published Tue Jan 29, 2019

]]>We characterize the influence of different intersection mixing rules for particle tracking simulations on transport properties through three-dimensional discrete fracture networks. It is too computationally burdensome to explicitly resolve all fluid dynamics within a large three-dimensional fracture...

[Phys. Rev. E 99, 013110] Published Fri Jan 25, 2019

]]>It was observed in the first part of this work [C. X. Yu *et al.*, Phys. Rev. E **97**, 013102 (2018)] that a Rayleigh-Taylor flow with a smoothly varying density at the interface permits a multiplicity of solutions for instability modes. Based on numerical solutions of the eigenvalue problem, a fitting ...

[Phys. Rev. E 99, 013109] Published Thu Jan 24, 2019

]]>By using cryogenic ${}^{4}\mathrm{He}$ gas as the working fluid in a cylindrical cell 0.3 m in both height and diameter, we study the influence of non-Oberbeck-Boussinesq (NOB) effects on the heat transfer in turbulent Rayleigh-Bénard convection (RBC). We show that the NOB effects increase the heat transfer efficie...

[Phys. Rev. E 99, 011101(R)] Published Wed Jan 23, 2019

]]>We investigate the dependency of the magnitude of heat transfer in a convection cell as a function of its inclination by means of experiments and simulations. The study is performed with a working fluid of large Prandtl number, $\mathrm{Pr}\simeq 480$, and at Rayleigh numbers $\mathrm{Ra}\simeq {10}^{8}$ and $\mathrm{Ra}\simeq 5\times {10}^{8}$ in a quasi-two-dimen...

[Phys. Rev. E 99, 013108] Published Tue Jan 22, 2019

]]>Previous work [Davidovits and Fisch, Phys. Rev. Lett. **116**, 105004 (2016)] demonstrated that the compression of a turbulent field can lead to a sudden viscous dissipation of turbulent kinetic energy (TKE), and that paper suggested this mechanism could potentially be used to design new fast-ignition s...

[Phys. Rev. E 99, 013107] Published Thu Jan 17, 2019

]]>We study boundary conditions applied to the macroscopic dynamics of Newtonian liquids from the view of microscopic particle systems. We assume the existence of microscopic boundary conditions that are uniquely determined from a microscopic description of the fluid and the wall. By using molecular dy...

[Phys. Rev. E 99, 013106] Published Mon Jan 14, 2019

]]>In relativistic fluid mechanics, positive entropy production is known to be insufficient for guaranteeing stability. Much stronger criteria for thermodynamic admissibility have become available in nonequilibrium thermodynamics. We here perform a linear stability analysis for a model of relativistic ...

[Phys. Rev. E 99, 013105] Published Thu Jan 10, 2019

]]>Turbulence mixing models of different degree of complexity are investigated for Rayleigh-Taylor mixing flows with reference to high-resolution implicit large eddy simulations. The models considered, in order of increasing complexity, comprise the (i) two-equation *K-L*, (ii) three-equation *K-L-a*, (iii...

[Phys. Rev. E 99, 013104] Published Wed Jan 09, 2019

]]>The evolution of a uniform interface subjected to a perturbed shock wave has been experimentally studied over a range of Atwood numbers $0.22\le A\le 0.68$ and Mach numbers $1.2\le M\le 1.8$ using a vertical shock tube. The perturbed shock wave is produced by diffracting a planar incident shock over a rigid cylinde...

[Phys. Rev. E 99, 013103] Published Tue Jan 08, 2019

]]>The transport of chemical species in porous media is ubiquitous in subsurface processes, including contaminant transport, soil drying, and soil remediation. We study vapor transport in a multiscale porosity material, a smectite clay, in which water molecules travel in mesopores and macropores betwee...

[Phys. Rev. E 99, 013102] Published Mon Jan 07, 2019

]]>We explore the effect of the magnetic Prandtl number Pm on energy and dissipation in fully resolved direct numerical simulations of steady-state, mechanically forced, homogeneous magnetohydrodynamic turbulence in the range $1/32<\mathrm{Pm}<32$. We compare the spectra and show that if the simulations are...

[Phys. Rev. E 99, 013101] Published Fri Jan 04, 2019

]]>One of the most intriguing features of Earth's axial magnetic dipole field, well known from the geological record, is its occasional and unpredictable reversal of polarity. Understanding the phenomenon is rendered very difficult by the highly nonlinear nature of the underlying magnetohydrodynamic pr...

[Phys. Rev. E 98, 063112] Published Thu Dec 27, 2018

]]>Fast-field-cycling nuclear-magnetic-resonance (FFC NMR) experimentation measures the spin-lattice relaxation rate ${T}_{1}^{-1}={R}_{1}$ as a function of NMR frequency $f$. It is a proven technique for probing the nanoscale dynamics of ${}^{1}\mathrm{H}$ spins over multiple timescales. In many porous systems, fluid is confined to q...

[Phys. Rev. E 98, 063110] Published Wed Dec 26, 2018

]]>Microscale swimming may be intuited to be dominated by background flows, sweeping away any untethered bodies with the prevalent flow direction. However, it has been observed that many microswimmers utilize ambient flows as guidance cues, in some cases resulting in net motion upstream, contrary to th...

[Phys. Rev. E 98, 063111] Published Wed Dec 26, 2018

]]>We derive the Green's function of unsteady Stokes equations near a plane boundary with no-slip boundary conditions. This provides flow due to an oscillating point force acting on fluid bounded by a wall. Our derivation is different from previous theories and resolves the apparent discrepancies of th...

[Phys. Rev. E 98, 063108] Published Thu Dec 20, 2018

]]>The two-dimensional natural convection of air in upper and a lower square cavities connected with a vertical vent is studied numerically and theoretically. At high Rayleigh numbers (Ra), it is revealed by the dynamic-mode-decomposition method that the plumes yield to a new sway mode, where the plume...

[Phys. Rev. E 98, 063109] Published Thu Dec 20, 2018

]]>We perform direct numerical simulations of a bidisperse suspension of heavy spherical particles in forced, homogeneous, and isotropic three-dimensional turbulence. We compute the joint distribution of relative particle distances and longitudinal relative velocities between particles of different ine...

[Phys. Rev. E 98, 063107] Published Thu Dec 13, 2018

]]>We theoretically and experimentally investigate low-Reynolds-number propulsion of geometrically achiral planar objects that possess a dipole moment and that are driven by a rotating magnetic field. Symmetry considerations (involving parity $\widehat{P}$ and charge conjugation $\widehat{C}$) establish correspondence betwe...

[Phys. Rev. E 98, 063105] Published Wed Dec 12, 2018

]]>The second- and third-order zonal oscillations of metallic droplets at high temperatures beyond 2000 K were experimentally achieved by electrostatic levitation. To quantitatively describe the suspension stability of different metallic droplets, a stability factor model was proposed as a function of ...

[Phys. Rev. E 98, 063106] Published Wed Dec 12, 2018

]]>Solid-solid phase transitions are commonly encountered at the atomic scale in alloys and in superatomic mesoscopic systems of colloidal particles. Here we investigate a solid-solid phase transition occurring at the macroscopic scale between lattices of liquid jets with different symmetries generated...

[Phys. Rev. E 98, 063104] Published Tue Dec 11, 2018

]]>This article reports the dominant governing role played by the direction of electric and magnetic fields on the internal advection pattern and strength within salt solution pendent droplets. The literature shows that solutal advection drives circulation cells within salt based droplets, even in the ...

[Phys. Rev. E 98, 063103] Published Mon Dec 10, 2018

]]>Due to their potential usefulness in engineering and medical applications, various artificial microswimmers have been proposed. In our previous paper *et al.* [T. Morita, T. Omori, and T. Ishikawa, Phys. Rev. E **98**, 023108 (2018)], we introduced a microcapsule swimmer that underwent amoeboidlike shape ...

[Phys. Rev. E 98, 063102] Published Fri Dec 07, 2018

]]>Motivated by cancer cell capture and sorting applications, we investigate the scalar velocity field of two-dimensional (2D) laminar flows through configurations of fixed congruent circular disks with a disordered hyperuniform (HU) distribution of the disk centers. Disordered HU many-particle systems...

[Phys. Rev. E 98, 063101] Published Wed Dec 05, 2018

]]>We investigate how clogging affects the transfer properties of a generic class of materials featuring a hydraulic network embedded in a matrix. We consider the flow of a liquid through fully saturated hydraulic networks which transfer heat (or mass) by advection and diffusion, and a matrix in which ...

[Phys. Rev. E 98, 053107] Published Tue Nov 27, 2018

]]>We propose an alternative strategy to modulate the acoustic radiation force (ARF) acting on an elastic sphere (ES) using laser irradiation. A mathematical model of the interaction of the acoustic plane wave with the laser-irradiated ES is developed to calculate the ARF acting on the ES. It is demons...

[Phys. Rev. E 98, 053105] Published Mon Nov 26, 2018

]]>A three-dimensional (3D) transition route for zero-pressure-gradient boundary layer over a flat plate is computationally investigated, for impulsive and nonimpulsive startup of harmonic wall excitation. A monochromatic frequency of excitation is chosen to perturb the boundary layer. The exciter plac...

[Phys. Rev. E 98, 053106] Published Mon Nov 26, 2018

]]>We present the equations for wicking in two- and three-dimensional porous media when liquid is evaporating through the wet front using the Green–Ampt saturated capillary flow model in polar and spherical geometries. The time-dependent behavior of two-dimensional wicking influenced by front interface...

[Phys. Rev. E 98, 053104] Published Fri Nov 16, 2018

]]>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

]]>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

]]>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

]]>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

]]>We present a numerical study of the time-dependent motion of a two-dimensional vesicle in a channel under an imposed flow. In a Poiseuille flow the shape of the vesicle depends on the flow strength, the mechanical properties of the membrane, and the width of the channel as reported in the past. This...

[Phys. Rev. E 98, 043111] Published Mon Oct 29, 2018

]]>In this paper we employ renormalized viscosity and thermal diffusivity to construct a subgrid-scale model for large eddy simulation (LES) of turbulent thermal convection. For LES, we add ${\nu}_{\mathrm{ren}}\propto {\mathrm{\Pi}}_{u}^{1/3}{(\pi /\mathrm{\Delta})}^{-4/3}$ to the kinematic viscosity; here ${\mathrm{\Pi}}_{u}$ is the turbulent kinetic energy flux, and $\mathrm{\Delta}$ is the grid s...

[Phys. Rev. E 98, 043109] Published Wed Oct 24, 2018

]]>In this paper, the theory for acoustic radiation force exerted by standing surface acoustic waves (SSAWs) is extended to a compressible sphere in inviscid fluids. The conventional theory, developed in plane standing waves, fails to predict the radiation force incident on particles in the SSAW. Our e...

[Phys. Rev. E 98, 043108] Published Tue Oct 23, 2018

]]>Drying of colloidal drops on solid surfaces is the widely known method to form self-assembled patterns. The underlying principle of this method is the phenomenon known as the coffee-ring effect. Here, we report a phenomenon of pattern formation involving not drying but conversely wetting and spreadi...

[Phys. Rev. E 98, 043107] Published Fri Oct 19, 2018

]]>The dynamics, instability, and pattern formation of thermally triggered thin liquid films are investigated numerically under a long-wave limit approximation. To determine the mechanisms responsible for instability growth and pattern formation in confined heated nanofilms, acoustic phonon (AP) and th...

[Phys. Rev. E 98, 043106] Published Mon Oct 15, 2018

]]>Sound can hold partially ionized sulfur at the center of a spherical bulb. We use the sulfur plasma itself to drive a 180 dB re 20 $\mu \mathrm{Pa}$ sound wave by periodically heating it with microwave pulses at a frequency that matches the lowest order, spherically symmetric, acoustic resonance of the bulb. To c...

[Phys. Rev. E 98, 043103] Published Fri Oct 12, 2018

]]>We investigate analytically the transport characteristics of the triangular bead-spring microswimmer and its dependence on the sizes of the beads as well as on the relative bead configurations. The microswimmer is composed of three beads connected by linear springs in an isosceles triangular arrange...

[Phys. Rev. E 98, 043104] Published Fri Oct 12, 2018

]]>The Richtmyer-Meshkov (RM) instability of a planar interface (${\mathrm{N}}_{2}-{\mathrm{SF}}_{6}$) subjected to a sinusoidal rippled shock, as the variant of a sinusoidal interface impinged by a planar shock, is investigated through high-order compressible multicomponent hydrodynamic simulations. The rippled shock is generated ...

[Phys. Rev. E 98, 043105] Published Fri Oct 12, 2018

]]>Experimental results have shown that resistivity index can deviate from Archie's law at low conductive phase saturation. Previous works have claimed that wettability and flow history are the two main factors causing this phenomenon. Herein, we investigate how the underlying fluid morphology influenc...

[Phys. Rev. E 98, 043102] Published Mon Oct 08, 2018

]]>We report experiments, modeling, and numerical simulations of the self–assembly of particle patterns obtained from a nanometric metallic square grid. Initially, nickel filaments of rectangular cross section are patterned on a ${\mathrm{SiO}}_{2}$ flat surface, and then they are melted by laser irradiation with $\sim 18$-...

[Phys. Rev. E 98, 043101] Published Thu Oct 04, 2018

]]>If a fluid flow is driven by a weak Gaussian random force, the nonlinearity in the Navier-Stokes equations is negligibly small and the resulting velocity field obeys Gaussian statistics. Nonlinear effects become important as the driving becomes stronger and a transition occurs to turbulence with ano...

[Phys. Rev. E 98, 033120] Published Fri Sep 28, 2018

]]>We study the response of a rarefied gas in a slab to the motion of its boundaries in the tangential direction. Different from previous investigations, we consider boundaries displacements at nonsmall Mach ($\mathrm{Ma}$) numbers, coupling the dynamic and thermodynamic gas states, and deviating the system from ...

[Phys. Rev. E 98, 033121] Published Fri Sep 28, 2018

]]>We numerically examine solutal convection in porous media, driven by the dissolution of carbon dioxide (${\mathrm{CO}}_{2}$) into water—an effective mechanism for ${\mathrm{CO}}_{2}$ storage in saline aquifers. Dissolution is associated with slow diffusion of free-phase ${\mathrm{CO}}_{2}$ into the underlying aqueous phase followed by density-dri...

[Phys. Rev. E 98, 033118] Published Thu Sep 27, 2018

]]>We develop a model for the microstructure and the stress, in dense suspensions of non-Brownian, perfectly smooth spheres at vanishing particle Reynolds number. These quantities are defined in terms of the second-order moment $\mathit{a}$ of the distribution function of the orientation unit vector between hydro...

[Phys. Rev. E 98, 033119] Published Thu Sep 27, 2018

]]>We present a numerical and theoretical investigation of the nonlinear spectral energy cascade of decaying finite-amplitude planar acoustic waves in a single-component ideal gas at standard temperature and pressure. We analyze various one-dimensional canonical flow configurations: a propagating trave...

[Phys. Rev. E 98, 033117] Published Tue Sep 25, 2018

]]>Permselective nanochannels can rectify the electric current transported through them similar to solid-state diodes. The rectification is due to symmetry breaking related to distribution of the nanochannels’ surface charge as well as the geometry. Thus far, most of the works related to the asymmetric...

[Phys. Rev. E 98, 033114] Published Mon Sep 24, 2018

]]>When two bubbles encounter each other in a moderate ultrasound field they coalesce into a single bubble that shows purely spherical oscillations. For a sufficiently large acoustic field, this coalescence can lead to sustained nonspherical oscillations of the resulting bubble. We experimentally captu...

[Phys. Rev. E 98, 033115] Published Mon Sep 24, 2018

]]>Statistical theory of turbulence in viscid incompressible fluid, described by the Navier-Stokes equation driven by random force, is reformulated in terms of scale-dependent fields ${\mathbf{u}}_{a}\left(x\right)$, defined as wavelet-coefficients of the velocity field $\mathbf{u}$ taken at point $x$ with the resolution $a$. Applying quantum ...

[Phys. Rev. E 98, 033116] Published Mon Sep 24, 2018

]]>The leaves of many plants are superhydrophobic, a property that may have evolved to clean the leaves by encouraging water droplets to bead up and roll off. Superhydrophobic surfaces can also exhibit reduced friction, and liquids flowing over such surfaces have been found to slip in apparent violatio...

[Phys. Rev. E 98, 033113] Published Fri Sep 21, 2018

]]>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

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