Latest papers in fluid mechanics
Author(s): K. Takamure and S. Ozono
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
Author(s): Michiko Shimokawa and Hidetusgu Sakaguchi
A study of the breakup of a droplet falling into a miscible solution of lower density shows that a nondimensional parameter determines the breakup number. A mechanism of the mode-selection based on the Rayleigh-Taylor instability for the growing vortex ring is discussed.
[Phys. Rev. Fluids 4, 013603] Published Wed Jan 30, 2019
Linear and nonlinear stability of a quasigeostrophic mixing layer subject to a uniform background shear
Author(s): Luca Biancofiore and Orkan M. Umurhan
The stability of a quasigeostrophic mixing layer is revisited from the kernel wave perspective with a focus on individual Rossby waves behavior. We further conduct nonlinear simulations which show how vortex pairing is hindered by introducing an adverse shear or a finite Rossby radius.
[Phys. Rev. Fluids 4, 013803] Published Wed Jan 30, 2019
Author(s): Sudarshan Konidena, K. Anki Reddy, and Anugrah Singh
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
Author(s): N. E. Sujovolsky and P. D. Mininni
We put forth a model that captures the vertical single- and two-particle dispersion in stably stratified turbulence. The model gives insight into the mixture of linear and nonlinear physics in these flows, and on the different physical processes responsible for vertical turbulent dispersion.
[Phys. Rev. Fluids 4, 014503] Published Tue Jan 29, 2019
Characterizing the impact of particle behavior at fracture intersections in three-dimensional discrete fracture networks
Author(s): Thomas Sherman, Jeffrey D. Hyman, Diogo Bolster, Nataliia Makedonska, and Gowri Srinivasan
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
Author(s): J. Sánchez Umbría and M. Net
A numerical study of the nonlinear torsional solutions of convection in rotating, internally heated, self-gravitating fluid spheres shows a sequence of transitions towards chaos in which heteroclinic chains connecting unstable periodic solutions can be recognized.
[Phys. Rev. Fluids 4, 013501] Published Fri Jan 25, 2019
Multiple eigenmodes of the Rayleigh-Taylor instability observed for a fluid interface with smoothly varying density. II. Asymptotic solution and its interpretation
Author(s): Ming Dong, Zhengfeng Fan, and Chengxin Yu
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
Unstable yet static initial state: A universal method for studying Rayleigh-Taylor instability and lock exchange
Author(s): Kazuya U. Kobayashi and Rei Kurita
An experimental method for investigating hydrodynamic instability combining light and a physical gel is proposed. Our method allows for a detailed study of hydrodynamic instabilities.
[Phys. Rev. Fluids 4, 013901] Published Thu Jan 24, 2019
Author(s): Jean-Christophe Ono-dit-Biot, Miguel Trejo, Elsie Loukiantcheko, Max Lauch, Elie Raphaël, Kari Dalnoki-Veress, and Thomas Salez
The hydroelastic wake created by a perturbation moving along a thin elastic sheet floating atop water is studied. The waves are characterized as a function of the perturbation speed and sheet thickness. Gravity, bending, and stretching are quantified and all are found to be important.
[Phys. Rev. Fluids 4, 014808] Published Thu Jan 24, 2019
Author(s): P. Urban, P. Hanzelka, T. Králík, M. Macek, V. Musilová, and L. Skrbek
By using cryogenic He4 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
Author(s): Linfeng Jiang, Chao Sun, and Enrico Calzavarini
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, Pr≃480, and at Rayleigh numbers Ra≃108 and Ra≃5×108 in a quasi-two-dimen...
[Phys. Rev. E 99, 013108] Published Tue Jan 22, 2019
Author(s): C. Tyler Bolles, Kevin Speer, and M. N. J. Moore
A normally-distributed unidirectional wave-field is observed in experiments to become highly skewed and non-Gaussian upon encountering an abrupt change in depth.
[Phys. Rev. Fluids 4, 011801(R)] Published Tue Jan 22, 2019
Experimental comparison of initiation of motion for submerged objects resting on fixed permeable and impermeable beds
Author(s): Heng Wu, Carlo C. Zuniga Zamalloa, Blake J. Landry, and Marcelo H. Garcia
Laboratory experiments suggest a larger Shields parameter value requirement to initiate motion on permeable beds than on impermeable ones, which is connected with the lower lift force on a permeable bed.
[Phys. Rev. Fluids 4, 013802] Published Tue Jan 22, 2019
Author(s): Ken Komoda and Susumu Goto
Direct numerical simulations reveal the three-dimensional flow structures, sustaining mechanism, and sustainability condition of developed turbulence in precessing spheroids.
[Phys. Rev. Fluids 4, 014603] Published Tue Jan 22, 2019
Author(s): Jie Yu
The exact Floquet theory reveals that the waveforms (eigenfunctions) of linear eigenwaves over a variable bed have complex features that are reminiscent of nonlinear waveforms. This is in contrast to the long-standing view that linear time harmonic waves are of permanent sinusoidal form.
[Phys. Rev. Fluids 4, 014806] Published Tue Jan 22, 2019
Author(s): Zhigang Zhu, Yalei Song, Xiaonan Liu, Dawu Xiao, Lei Yang, and Liang Huang
We observed in a vibrating rectangular narrow tank a cramped water wave that acts as a sequence of load-carrying beams with one end oscillating and the other end almost pinned to the wall. We find the wave to be composed of just two harmonic waves. Nonlinearities account for this robust structure.
[Phys. Rev. Fluids 4, 014807] Published Tue Jan 22, 2019
Author(s): Uddalok Sen, Souvick Chatterjee, Julie Crockett, Ranjan Ganguly, Lisha Yu, and Constantine M. Megaridis
A liquid jet striking orthogonally a horizontal superhydrophilic surface can produce a circular hydraulic jump. The same jet impinging on a superhydrophobic surface forms a film that breaks up into droplets. The same superhydrophobic surface with a wettable ring causes a different jet impact outcome.
[Phys. Rev. Fluids 4, 014002] Published Fri Jan 18, 2019
Author(s): Daniel P. Willen and Andrea Prosperetti
We analyze resolved simulations of up to 2000 spherical particles suspended in an incoming fluid stream with single-particle Reynolds number from 40-110 and volume fraction 9-35%. Diffusivities, pair distributions, and other quantities are found. Tetrads (four particle groups) are also studied.
[Phys. Rev. Fluids 4, 014304] Published Fri Jan 18, 2019
Self-consistent feedback mechanism for the sudden viscous dissipation of finite-Mach-number compressing turbulence
Author(s): Alejandro Campos and Brandon E. Morgan
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