Physical Review E
Author(s): Gaurav Singh and Rajaram Lakkaraju
A high level of mixing by passive means is a desirable feature in microchannels for various applications, and use of flexible obstacles (or plates) is one of the prime choices in that regard. To gain further insight, we carry out two-dimensional numerical simulations for flow past one or two flexibl...
[Phys. Rev. E 100, 023109] Published Tue Aug 20, 2019
Identifying the pattern of breakdown in a laminar-turbulent transition via binary sequence statistics and cellular-automaton simulations
Author(s): Wen Zhang, Peiqing Liu, Hao Guo, Minping Wan, Jianchun Wang, and Shiyi Chen
The laminar-turbulent transition induced by two-dimensional steplike roughness is investigated focusing on the pattern of breakdown. The statistics of the turbulent burst rate is found to be significantly different from the prediction of the classical theory. A systematic investigation of the patter...
[Phys. Rev. E 100, 023110] Published Tue Aug 20, 2019
Author(s): Itzhak Fouxon and Michael Mond
We study the statistics of fluid (gas) density and concentration of passive tracer particles (dust) in compressible turbulence. As Ma increases from small or moderate values, the density and the concentration in the inertial range go through a phase transition from a finite continuous smooth distrib...
[Phys. Rev. E 100, 023111] Published Tue Aug 20, 2019
Effects of electronic friction from the walls on water flow in carbon nanotubes and on water desalination
Author(s): J. B. Sokoloff
A mechanism for removal of salt from salt water is discussed, which results from friction due to Ohm's law heating, resulting from motion of an electron charge induced in the tube walls by the water molecules’ dipoles and the ions’ charges. The desalination occurs because this friction is larger for...
[Phys. Rev. E 100, 023112] Published Tue Aug 20, 2019
Author(s): Matteo Foresti and Renzo L. Ricca
In this paper we demonstrate that new phase defects of the Gross-Pitaevskii equation (GPE) can be produced as a Aharonov-Bohm effect resulting from pure phase twist injection on existing defects. This is a phenomenon that has physical justification in the hydrodynamic interpretation of GPE. Here we ...
[Phys. Rev. E 100, 023107] Published Fri Aug 16, 2019
Author(s): Yixin Zhang, James E. Sprittles, and Duncan A. Lockerby
This work combines molecular dynamics simulations with analytical techniques to study the effect of thermal fluctuations on the stability of thin liquid films. Results from a stochastic thin-film equation agree well with those from the simulations, but disagree with a deterministic equation. The authors conclude that thermal fluctuations play an important role in the dynamics of thin films at the nanoscale.
[Phys. Rev. E 100, 023108] Published Fri Aug 16, 2019
Author(s): Leonid. V. Mirantsev
Molecular dynamics simulations of equilibrium structures and flows of nonpolar argon atoms confined by single-walled carbon nanotubes (SWCNTs) with circular cross section and rectangular cross section having the same area and the ratio between its sides 1:4 have been performed. It has been shown tha...
[Phys. Rev. E 100, 023106] Published Tue Aug 13, 2019
Author(s): Jacob S. Bach and Henrik Bruus
Bulk-driven acoustic (Eckart) streaming is the steady flow resulting from the time-averaged acoustic energy flux density in the bulk of a viscous fluid. In simple cases, like the one-dimensional single standing-wave resonance, this energy flux is negligible, and therefore the bulk-driven streaming i...
[Phys. Rev. E 100, 023104] Published Wed Aug 07, 2019
Numerical investigation of vibration-induced droplet shedding on smooth surfaces with large contact angles
Author(s): Mostafa Moradi, Mohammad Hassan Rahimian, and Seyed Farshid Chini
In this work, numerical simulations are performed to study the droplet response to the vertical vibration of the substrate, under various frequencies and amplitudes using the multiphase lattice Boltzmann method. First, the numerical results are validated against published experimental data. The effe...
[Phys. Rev. E 100, 023105] Published Wed Aug 07, 2019
Author(s): Koshun Ogawa, Haruki Oga, Hiroki Kusudo, Yasutaka Yamaguchi, Takeshi Omori, Samy Merabia, and Laurent Joly
Molecular dynamics simulations are a powerful tool to characterize liquid-solid friction. A slab configuration with periodic boundary conditions in the lateral dimensions is commonly used, where the measured friction coefficient could be affected by the finite lateral size of the simulation box. Her...
[Phys. Rev. E 100, 023101] Published Mon Aug 05, 2019
Author(s): J. Meibohm and B. Mehlig
We study a one-dimensional model for heavy particles in a compressible fluid. The fluid-velocity field is modeled by a persistent Gaussian random function, and the particles are assumed to be weakly inertial. Since one-dimensional fluid-velocity fields are always compressible, the model exhibits spa...
[Phys. Rev. E 100, 023102] Published Mon Aug 05, 2019
Author(s): T. Zagvozkin, A. Vorobev, and T. Lyubimova
The stability of a shear flow imposed along a diffusive interface that separates two miscible liquids (a heavier liquid lies underneath) is studied using direct numerical simulations. The phase-field approach is employed for description of a thermo- and hydrodynamic evolution of a heterogeneous bina...
[Phys. Rev. E 100, 023103] Published Mon Aug 05, 2019
Kinetics of coarsening have dramatic effects on the microstructure: Self-similarity breakdown induced by viscosity contrast
Author(s): Hervé Henry and György Tegze
The viscous coarsening of a phase separated mixture is studied and the effects of the viscosity contrast between the phases are investigated. From an analysis of the microstructure, it appears that for moderate departure from the perfectly symmetric regime the self-similar bicontinuous regime is rob...
[Phys. Rev. E 100, 013116] Published Mon Jul 29, 2019
Author(s): Paolo Falsaperla, Andrea Giacobbe, and Giuseppe Mulone
We prove that the plane Couette and Poiseuille flows are nonlinearly stable if the Reynolds number is less than ReOrr(2π/(λsinθ))/sinθ when a perturbation is a tilted perturbation in the direction x′ which forms an angle θ∈(0,π/2] with the direction i of the basic motion and does not depend on x′. R...
[Phys. Rev. E 100, 013113] Published Fri Jul 26, 2019
Author(s): Vikash Pandey, Prasad Perlekar, and Dhrubaditya Mitra
This work presents two-dimensional simulations of particles embedded in a turbulent flow. The particles are capable of modifying the flow by interacting with the fluid. The authors study the behavior of this system as the Stokes number and the particle concentration change, and uncover a new scaling behavior that shows a dependence on those two variables.
[Phys. Rev. E 100, 013114] Published Fri Jul 26, 2019
Author(s): V. Langlois, V. H. Trinh, and C. Perrot
Numerical and analytical methods at both micro- and mesoscales are used to study how the electrical resistivity and the high-frequency tortuosity of solid foam are modified by the presence of membranes that partially or totally close the cell windows connecting neighbor pores. Finite-element-method ...
[Phys. Rev. E 100, 013115] Published Fri Jul 26, 2019
Author(s): Balachandra Suri, Ravi Kumar Pallantla, Michael F. Schatz, and Roman O. Grigoriev
Recent studies suggest that unstable recurrent solutions of the Navier-Stokes equation provide new insights into dynamics of turbulent flows. In this study, we compute an extensive network of dynamical connections between such solutions in a weakly turbulent quasi-two-dimensional Kolmogorov flow tha...
[Phys. Rev. E 100, 013112] Published Thu Jul 25, 2019
Author(s): Yuejin Zhu, Longkun Gao, Kai Hong Luo, Jianfeng Pan, Zhenhua Pan, and Penggang Zhang
The interaction between a planar shock wave and a spherical flame is studied numerically for an ethylene-oxygen-nitrogen gas mixture. Influences of different initial reactive gas mixture gradients on the shock-flame interaction are investigated by using high-resolution computational simulations. The...
[Phys. Rev. E 100, 013111] Published Tue Jul 23, 2019
Author(s): Changwoo Kang and Parisa Mirbod
This work analyzes the porosity effects on laminar flow and drag reduction of Newtonian fluids flowing over and through permeable surfaces. A fully developed laminar flow in a channel partially replaced with a porous material is considered. The analytical solutions for the velocity and shear stress ...
[Phys. Rev. E 100, 013109] Published Mon Jul 22, 2019
Author(s): Domenico G. Meduri, François Lignières, and Laurène Jouve
We investigate numerically the flow of an electrically conducting fluid in a rapidly rotating spherical shell where the inner boundary spins slightly faster than the outer one. The magnetic field evolves self-consistently from an initial dipolar configuration of weak amplitude, and a toroidal field ...
[Phys. Rev. E 100, 013110] Published Mon Jul 22, 2019