We analyze the statistical properties of three-dimensional (3D) turbulence in a rotating fluid. To this end we introduce a generating functional to study the statistical properties of the velocity field v. We obtain the master equation from the Navier-Stokes equation in a rotating frame and thence a...

[Phys. Rev. E 85, 026311] Published Fri Feb 10, 2012

We experimentally investigate the thermocapillary migration induced by local laser heating of the advancing front of a growing droplet confined in a microfluidic channel. When heating implies an effective increase in interfacial tension, the laser behaves as a “soft door” whose stiffness can be tune...

[Phys. Rev. E 85, 026310] Published Fri Feb 10, 2012

The immiscible displacement of oil by water in a circular microchannel was investigated. A fused silica microchannel with an inner diameter of 250 μm and a length of 7 cm was initially filled with a viscous silicone oil. Only water then was injected into the channel. We describe our flow observation...

[Phys. Rev. E 85, 026309] Published Wed Feb 08, 2012

Deterministic route to turbulence creation in 2D wall boundary layer is shown here by solving full Navier-Stokes equation by dispersion relation preserving (DRP) numerical methods for flow over a flat plate excited by wall and free stream excitations. Present results show the transition caused by wa...

[Phys. Rev. E 85, 026308] Published Wed Feb 08, 2012

In this work, a pseudocompressible approximation relevant for turbulent mixing flows encountered in shock tubes is derived. The asymptotic analysis used for this purpose puts forward the role played by four dimensionless numbers on the flow compressibility, namely, the turbulent, deformation, strati...

[Phys. Rev. E 85, 026307] Published Wed Feb 08, 2012

We numerically investigate the structures of the near-plate temperature profiles close to the bottom and top plates of turbulent Rayleigh-Bénard flow in a cylindrical sample at Rayleigh numbers Ra=10⁸ to Ra=2×10¹² and Prandtl numbers Pr=6.4 and Pr=0.7 with the dynamical frame method [ Zhou and Xia ...

[Phys. Rev. E 85, 027301] Published Tue Feb 07, 2012

The present study offers a paradigm on the stability of two-component miscible displacements in a homogeneous porous medium. The components have, in general, different mobility ratios, may diffuse at different rates, and are convected at different speeds. As a result, one of the components may lag b...

[Phys. Rev. E 85, 026306] Published Tue Feb 07, 2012

We analyze a possible extension of Gioia and Chakraborty's momentum transfer model of friction in steady turbulent pipe flows [ Phys. Rev. Lett. 96 044502 (2006)] to the case of time- and/or space-dependent turbulent flows. The end result is an expression for the stress at the wall as the sum of a ...

[Phys. Rev. E 85, 026305] Published Tue Feb 07, 2012

The driving parametric regions in frequency-amplitude space and the optimal parameters for single-bubble sonoluminescence (SBSL) in alcohol aqueous solutions are studied systematically by taking measurements of the spectrum and bubble dynamics. The experimental results show that with an increase in ...

[Phys. Rev. E 85, 026304] Published Tue Feb 07, 2012

The small-scale dynamo is a process by which turbulent kinetic energy is converted into magnetic energy, and thus it is expected to depend crucially on the nature of the turbulence. In this paper, we present a model for the small-scale dynamo that takes into account the slope of the turbulent veloci...

[Phys. Rev. E 85, 026303] Published Fri Feb 03, 2012

The breakup of small solid aggregates in homogeneous and isotropic turbulence is studied theoretically and by using direct numerical simulations at high Reynolds number, Re_λ≃400. We show that turbulent fluctuations of the hydrodynamic stress along the aggregate trajectory play a key role in determin...

[Phys. Rev. E 85, 025301] Published Fri Feb 03, 2012

Starting from a classical picture of shear viscosity we construct a stationary velocity gradient in a microscopic parton cascade. Employing the Navier-Stokes ansatz we extract the shear viscosity coefficient η. For elastic isotropic scatterings we find an excellent agreement with the analytic values...

[Phys. Rev. E 85, 026302] Published Thu Feb 02, 2012

We present a spectral linear analysis in terms of advected Fourier modes to describe the behavior of a fluid submitted to four constraints: shear (with rate S), rotation (with angular velocity Ω), stratification, and magnetic field within the linear spectral theory or the shearing box model in astro...

[Phys. Rev. E 85, 026301] Published Wed Feb 01, 2012

Hyperbolicity is an important concept in dynamical system theory; however, we know little about the hyperbolicity of concrete physical systems including fluid motions governed by the Navier-Stokes equations. Here, we study numerically the hyperbolicity of the Navier-Stokes equation on a two-dimensio...

[Phys. Rev. E 85, 016331] Published Tue Jan 31, 2012

The dynamic interactions between a semipermeable membrane and a long, thin layer of liquid beneath it are investigated in the context of drying processes. The membrane separates two aqueous solutions of sugar, and the transport of water across the membrane is driven by concentration and pressure gra...

[Phys. Rev. E 85, 016330] Published Tue Jan 31, 2012

The effect of ambient temperature on the parameters of the single-bubble sonoluminescence in sulfuric acid (SA) diluted in water is studied. Using a hydrochemical model, three dominant instabilities of shape, Bjerknes, and diffusion are considered. The phase diagrams of the bubble in the (R₀ − P_a) s...

[Phys. Rev. E 85, 016329] Published Tue Jan 31, 2012

We consider long-wave Marangoni convection in a liquid layer atop a substrate of low thermal conductivity, heated from below. We demonstrate that the critical perturbations are materialized at the wave number K∼√Bi, where Bi is the Biot number which characterizes the weak heat flux from the free sur...

[Phys. Rev. E 85, 016328] Published Tue Jan 31, 2012

We calculate the acoustic radiation force from an ultrasound wave on a compressible, spherical particle suspended in a viscous fluid. Using Prandtl-Schlichting boundary-layer theory, we include the kinematic viscosity of the solvent and derive an analytical expression for the resulting radiation for...

[Phys. Rev. E 85, 016327] Published Mon Jan 30, 2012

An experimental demonstration of reaction-driven viscous fingering developing when a more viscous solution of a reactant A displaces a less viscous miscible solution of another reactant B is presented. In the absence of reaction, such a displacement of one fluid by another less mobile one is classic...

[Phys. Rev. E 85, 015304] Published Mon Jan 30, 2012

The mixing between two miscible liquids subject to vertical vibrations is studied by way of experiments and a two-dimensional numerical model. The experimental setup consisted of a rectangular cell in which the lighter fluid was placed above the denser one. The diffuse interface was then visualized ...

[Phys. Rev. E 85, 016326] Published Fri Jan 27, 2012

We model a pair of hydrodynamically interacting particles confined in a channel with thin rectangular cross section. We find that the particles have a finite region of attraction, which arises from the screening of dipolar hydrodynamic interactions by the side walls. Outside this region, the two par...

[Phys. Rev. E 85, 016325] Published Fri Jan 27, 2012

We describe a generalization of the tensorial slip boundary condition, originally justified for a thick (compared to texture period) channel, to any channel thickness. The eigenvalues of the effective slip-length tensor, however, in general case become dependent on the gap and cannot be viewed as a ...

[Phys. Rev. E 85, 016324] Published Fri Jan 27, 2012

This is the second part of a two-part study on the generation of droplets at a microfluidic T-junction operating in the transition regime. In the preceding paper [ Phys. Rev. E 85 016322 (2012)], we presented our experimental observations of droplet formation and decomposed the process into three s...

[Phys. Rev. E 85, 016323] Published Thu Jan 26, 2012

This is the first part of a two-part study on the generation of droplets at a microfluidic T-junction operating in the transition regime where confinement of the droplet creates a large squeezing pressure that influences droplet formation. In this regime, the operation of the T-junction depends on t...

[Phys. Rev. E 85, 016322] Published Thu Jan 26, 2012

We introduce a new mechanism for the propulsion and separation by chirality of small ferromagnetic particles suspended in a liquid. Under the action of a uniform dc magnetic field H and an ac electric field E isomers with opposite chirality move in opposite directions. Such a mechanism could have a ...

[Phys. Rev. E 85, 016321] Published Wed Jan 25, 2012

We present a theoretical scheme to calculate the electrophoretic motion of charged colloidal particles immersed in complex (non-Newtonian) fluids possessing shear-rate-dependent viscosities. We demonstrate that this non-Newtonian rheology leads to an explicit shape and size dependence of the electro...

[Phys. Rev. E 85, 016320] Published Wed Jan 25, 2012

Laser-induced breakdown of an optically trapped nanoparticle is a unique system for studying cavitation dynamics. It offers additional degrees of freedom, namely the nanoparticle material, its size, and the relative position between the laser focus and the center of the optically trapped nanoparticl...

[Phys. Rev. E 85, 016319] Published Wed Jan 25, 2012

Capillary processes greatly influence vapor mediated transport dynamics and associated changes in liquid phase content of porous media. Rapid x-ray synchrotron tomography measurements were used to resolve liquid-vapor interfacial dynamics during evaporation and condensation within submillimetric por...

[Phys. Rev. E 85, 016317] Published Mon Jan 23, 2012

A promising approach to the modeling of anomalous (non-Gaussian) dispersion in flow through heterogeneous porous media is the continuous-time random walk (CTRW) method. In such a formula on the waiting time distribution ψ(t) is usually assumed to be given by ψ(t)∼t^−1−α, with α fitted to the experime...

[Phys. Rev. E 85, 016316] Published Mon Jan 23, 2012

We characterize the generation of flow vortices in nanoscale confinements under the combined effects of patterned surface charge density and substrate wettability. Using molecular dynamics simulations, we elucidate the effects of ion solvation and steric interactions toward influencing the resultant...

[Phys. Rev. E 85, 016315] Published Mon Jan 23, 2012