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

]]>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

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