Latest papers in fluid mechanics
Author(s): Purba Chatterjee, Edmund M. Tang, Pankaj Karande, and Patrick T. Underhill
In many applications of synthetic motors objects are moved through environments with component mixtures. Here active colloid propulsion is experimentally probed versus solution viscosity in hydrogen peroxide solutions, and interpreted with existing diffusion reaction models of self-diffusiophoresis.
[Phys. Rev. Fluids 3, 014101] Published Mon Jan 08, 2018
<i>A priori</i> analysis of differential diffusion for model development for scale-resolving simulations
Author(s): Franziska Hunger, Felix Dietzsch, Michael Gauding, and Christian Hasse
Direct numerical simulation data of a jet with two passive scalars is compared to explicitly filtered data of the same case with regard to the influence of the turbulent/nonturbulent interface (TNTI) on differential diffusion. Filtering is found to affect differential diffusion differently at the TNTI and in the jet core.
[Phys. Rev. Fluids 3, 014601] Published Mon Jan 08, 2018
Author(s): Yihua Ren, Wei Cui, and Shuiqing Li
We report an electrohydrodynamic instability in a premixed stagnation flame under manipulations of a dc electric field. This instability occurs when the electric field strength is at a certain value below the breakdown threshold, which is 0.75 kV/cm in the experimental setup. Above this value the fl...
[Phys. Rev. E 97, 013103] Published Fri Jan 05, 2018
Author(s): Paul Ritter, Stefan Zammert, Baofang Song, Bruno Eckhardt, and Marc Avila
In transitional pipe flow, isolated turbulent spots carry substantial pressure and velocity fluctuations as they travel along the pipe. A model is proposed that links the propagation speed of such spots with the exact coherent solutions to their spatial localization rate.
[Phys. Rev. Fluids 3, 013901] Published Fri Jan 05, 2018
Author(s): Nicholas G. Chisholm and Aditya S. Khair
The ability of a self-propelled swimmer to displace fluid—thus inducing mixing—in terms of the drift volume is assessed. The drift volume is found to be generally large when the Reynolds number is small, while at larger Reynolds numbers, it varies widely depending on the kinematics of swimming.
[Phys. Rev. Fluids 3, 014501] Published Fri Jan 05, 2018
Multiple eigenmodes of the Rayleigh-Taylor instability observed for a fluid interface with smoothly varying density
Author(s): C. X. Yu, C. Xue, J. Liu, X. Y. Hu, Y. Y. Liu, W. H. Ye, L. F. Wang, J. F. Wu, and Z. F. Fan
In this article, multiple eigen-systems including linear growth rates and eigen-functions have been discovered for the Rayleigh-Taylor instability (RTI) by numerically solving the Sturm-Liouville eigen-value problem in the case of two-dimensional plane geometry. The system called the first mode has ...
[Phys. Rev. E 97, 013102] Published Thu Jan 04, 2018
Author(s): Takuma Hori, Takafumi Kamino, Yuta Yoshimoto, Shu Takagi, and Ikuya Kinefuchi
We develop molecular transport simulation methods that simultaneously deal with gas- and surface-phase diffusions to determine the effect of surface diffusion on the overall diffusion coefficients. The phenomenon of surface diffusion is incorporated into the test particle method and the mean square ...
[Phys. Rev. E 97, 013101] Published Wed Jan 03, 2018
[Phys. Rev. Fluids 3, 010002] Published Wed Jan 03, 2018
Effects of the Mach number on the evolution of vortex-surface fields in compressible Taylor-Green flows
Author(s): Naifu Peng and Yue Yang
The vortex-surface field (VSF) is extended to investigate the vortex dynamics in compressible Taylor-Green flows at a range of Mach numbers. The compressibility effect on the process of vortex reconnection and the interaction of shocklets and vortex surfaces using VSFs is elucidated.
[Phys. Rev. Fluids 3, 013401] Published Wed Jan 03, 2018
Author(s): Jon Alm Eriksen, Renaud Toussaint, Knut Jørgen Måløy, Eirik Flekkøy, Olivier Galland, and Bjørnar Sandnes
Gravity induces parallel growth of finger structures which forms when air displaces a granular-liquid mixture. The alignment direction, which varies between horizontal and vertical, is explained by the interplay between surface tension, yield stresses, and the hydrostatic potential.
[Phys. Rev. Fluids 3, 013801] Published Wed Jan 03, 2018
Editorial: A Tale of Two Anniversaries: 125 Years of the <i>Physical Review</i> and 25 Years of <i>Physical Review E</i>
Author(s): Matthew Salter and Michael Thoennessen
[Phys. Rev. Fluids 3, 010001] Published Tue Jan 02, 2018
Author(s): Marie Farge, Naoya Okamoto, Kai Schneider, and Katsunori Yoshimatsu
We present numerical simulations of the three-dimensional Galerkin truncated incompressible Euler equations that we integrate in time while regularizing the solution by applying a wavelet-based denoising. For this, at each time step, the vorticity field is decomposed into wavelet coefficients, which...
[Phys. Rev. E 96, 063119] Published Fri Dec 29, 2017
Author(s): Yukinori Kametani, Ayane Kotake, Koji Fukagata, and Naoko Tokugawa
Drag reduction capability of uniform blowing in supersonic turbulent boundary layers is investigated by means of direct numerical simulation of channel flows with uniform blowing on one side and suction on the other side under subsonic and supersonic conditions.
[Phys. Rev. Fluids 2, 123904] Published Fri Dec 29, 2017
Author(s): Hassan Arbabi and Igor Mezić
The Koopman mode decomposition provides a fully data-driven framework for comprehensive dynamic analysis of complex flows. For example, the evolution of Koopman eigenvalues computed from data clearly indicates the sequence of bifurcations occurring in the state space of the flow.
[Phys. Rev. Fluids 2, 124402] Published Fri Dec 29, 2017
Author(s): X. Gloerfelt and J.-C. Robinet
A method is proposed to trigger inflow turbulence while minimizing spurious noise in order to study the noise radiated directly by a turbulent boundary layer. The strategy is based on a controlled transition by entering a resonant triad of unstable modes based on an inflectional velocity profile.
[Phys. Rev. Fluids 2, 124603] Published Fri Dec 29, 2017
Author(s): Jinfu Liang and Yu An
We perform a computational fluid dynamics simulation of trivalent terbium [Tb(III)] ion line emissions from single-bubble sonoluminescence (SBSL). Our simulation includes dynamic boundary conditions as well as the effects of gas properties and quenching by species, such as nitrite ion (NO2−). Simula...
[Phys. Rev. E 96, 063118] Published Thu Dec 28, 2017
Author(s): Monika Nitsche
Trajectories of vortex pairs deflected by an inclined plate undergo topological discontinuities as the plate length or angle changes. In fact, the vortex winding number jumps in a self-similar fractal fashion across gaps within gaps within gaps ad infinitum, which trap the vortices.
[Phys. Rev. Fluids 2, 124702] Published Thu Dec 28, 2017
Author(s): Juan Shi and Thomas R. Powers
Swimming microorganisms commonly encounter anisotropic environments, such as a biofilm or a liquid-crystalline solution. A simple theory for a Taylor sheet in a nematic liquid crystal is used to calculate how the swimming speed depends on the angle between the swimmer and the nematic director and also on the torque that tends to align the swimmer with the director.
[Phys. Rev. Fluids 2, 123102] Published Wed Dec 27, 2017
Asymptotic analysis of the contact-line microregion for a perfectly wetting volatile liquid in a pure-vapor atmosphere
Author(s): A. Ye. Rednikov and P. Colinet
Focused on evaporation-induced contact angles, asymptotic analyses in the limits of weak and strong Kelvin effects in the framework of Wayner’s and de Gennes’ paradigms permit a unified treatment and systematization of various isolated cases encountered in the literature.
[Phys. Rev. Fluids 2, 124006] Published Wed Dec 27, 2017
Author(s): C. A. Davy and P. M. Adler
The macroscopic permeability of a natural shale is determined by using structural measurements on three different scales. Transmission electron microscopy yields two-dimensional (2D) images with pixels smaller than 1 nm; these images are used to reconstruct 3D nanostructures. Three-dimensional focus...
[Phys. Rev. E 96, 063116] Published Tue Dec 26, 2017