Physical Review E
Author(s): P. Salgado Sánchez, J. Fernández, I. Tinao, and J. Porter
Experiments on vibrated fluids confined in cylindrical and cuboidal containers were performed under the reduced gravity conditions of a parabolic flight. The results constitute a systematic quantitative investigation of the vibroequilibria effect, which refers to the reorientation of vibrated fluids...
[Phys. Rev. E 100, 063103] Published Tue Dec 10, 2019
Author(s): Pei-Yi Zou, Yu-Hsiang Lai, and Jing-Tang Yang
In this work we studied the differences in flight kinematics and aerodynamics that could relate to differences in wing morphologies of a dragonfly and a damselfly. The damselflies and dragonflies normally fly with the fore wing or hind wing in the lead, respectively. The wing of the damselfly is pet...
[Phys. Rev. E 100, 063102] Published Wed Dec 04, 2019
Generation of a large-scale vorticity in a fast-rotating density-stratified turbulence or turbulent convection
Author(s): Igor Rogachevskii and Nathan Kleeorin
We find an instability resulting in generation of large-scale vorticity in a fast-rotating small-scale turbulence or turbulent convection with inhomogeneous fluid density along the rotational axis in anelastic approximation. The large-scale instability causes excitation of two modes: (i) the mode wi...
[Phys. Rev. E 100, 063101] Published Mon Dec 02, 2019
Author(s): Juan Sánchez Umbría and Marta Net
A mechanism for the cyclic generation of bursts of magnetic fields by nonlinear torsional flows of complex time dependence but very simple spatial structure is described. These flows were obtained numerically as axisymmetric solutions of convection in internally heated rotating fluid spheres in the ...
[Phys. Rev. E 100, 053110] Published Tue Nov 26, 2019
Author(s): F. J. García, H. González, F. J. Gómez-Aguilar, A. A. Castrejón-Pita, and J. R. Castrejón-Pita
A temporal analysis of the evolution of Gaussian wave packets in cylindrical capillary jets is presented through both a linear two-mode formulation and a one-dimensional nonlinear numerical scheme. These analyses are normally applicable to arbitrary initial conditions but our study focuses on pure-i...
[Phys. Rev. E 100, 053111] Published Tue Nov 26, 2019
Author(s): Jian Deng, Xuerui Mao, and Fangfang Xie
A direction adaptive approach for the reduction of drag and the suppression of lift fluctuation in flow passing a circular cylinder is developed. Flexible filaments are attached to the surface of the cylinder, and different configurations, including the number, lengths, and angles of attachment of t...
[Phys. Rev. E 100, 053107] Published Mon Nov 25, 2019
Author(s): Quan Ding, Tianyou Wang, and Zhizhao Che
It is generally accepted that a Worthington jet occurs when a droplet impacts onto a liquid pool. However, in this experimental study of the impact of viscous droplets onto a less-viscous liquid pool, we identify another jet besides the Worthington jet, forming a two-jet phenomenon. The two jets, a ...
[Phys. Rev. E 100, 053108] Published Mon Nov 25, 2019
Author(s): Liam C. Morrow, Michael C. Dallaston, and Scott W. McCue
We study a model for the evolution of an axially symmetric bubble of inviscid fluid in a homogeneous porous medium otherwise saturated with a viscous fluid. The model is a moving boundary problem that is a higher-dimensional analog of Hele-Shaw flow. Here we are concerned with the development of pin...
[Phys. Rev. E 100, 053109] Published Mon Nov 25, 2019
Author(s): Ivan S. Maksymov and Andrey Pototsky
Liquid drops and vibrations are ubiquitous in both everyday life and technology, and their combination can often result in fascinating physical phenomena opening up intriguing opportunities for practical applications in biology, medicine, chemistry, and photonics. Here we study, theoretically and ex...
[Phys. Rev. E 100, 053106] Published Wed Nov 20, 2019
Author(s): M. G. Cabezas, M. A. Herrada, and José M. Montanero
We study numerically the basic flow and linear stability of a capillary jet confined in a rectangular microchannel. We consider both the case where the interface does not touch the solid surfaces and that in which the jet adheres to them with a contact angle slightly smaller than 180∘. Given an arbi...
[Phys. Rev. E 100, 053104] Published Mon Nov 18, 2019
Determination of energy flux rate in homogeneous ferrohydrodynamic turbulence using two-point statistics
Author(s): Sukhdev Mouraya and Supratik Banerjee
Under the influence of an external magnetic field H, the suspended ferromagnetic particles of a laminar ferrofluid flow try to be oriented along H through a relaxation mechanism. Turbulence affects the interaction between the magnetization of each suspended particle and the external field thereby le...
[Phys. Rev. E 100, 053105] Published Mon Nov 18, 2019
Author(s): Vaibhav Palkar, Pavel Aprelev, Arthur Salamatin, Artis Brasovs, Olga Kuksenok, and Konstantin G. Kornev
Magnetic nanorods rotating in a viscous liquid are very sensitive to any ambient magnetic field. We theoretically predicted and experimentally validated the conditions for two-dimensional synchronous and asynchronous rotation as well as three-dimensional precession and tumbling of nanorods in an amb...
[Phys. Rev. E 100, 051101(R)] Published Wed Nov 13, 2019
Author(s): Christiane Schneide, Martin Stahn, Ambrish Pandey, Oliver Junge, Péter Koltai, Kathrin Padberg-Gehle, and Jörg Schumacher
Coherent circulation rolls and their relevance for the turbulent heat transfer in a two-dimensional Rayleigh-Bénard convection model are analyzed. The flow is in a closed cell of aspect ratio four at a Rayleigh number Ra=106 and at a Prandtl number Pr=10. Three different Lagrangian analysis techniqu...
[Phys. Rev. E 100, 053103] Published Mon Nov 11, 2019
Author(s): B. Dastvareh, J. Azaiez, and P. A. Tsai
Due to the high surface area to volume ratio of nanoparticles, nanocatalytic reactive flows are widely utilized in various applications, such as water purification, fuel cell, energy storage, and biodiesel production. The implementation of nanocatalysts in porous media flow, such as oil recovery and...
[Phys. Rev. E 100, 053102] Published Fri Nov 08, 2019
Energy and enstrophy spectra and fluxes for the inertial-dissipation range of two-dimensional turbulence
Author(s): Akanksha Gupta, Rohith Jayaram, Anando G. Chaterjee, Shubhadeep Sadhukhan, Ravi Samtaney, and Mahendra K. Verma
In this paper, using Pao's conjecture [Y.-H. Pao, Phys. Fluids 8, 1063 (1965)], we derive expressions for the spectra and fluxes of kinetic energy and enstrophy for two-dimensional (2D) forced turbulence that extend beyond the inertial range. In these expressions, the fluxes and the spectra contain ...
[Phys. Rev. E 100, 053101] Published Mon Nov 04, 2019
Kinetic and internal energy transfer in implicit large-eddy simulations of forced compressible turbulence
Author(s): Wolfram Schmidt and Philipp Grete
We revisit the problem of how energy transfer through the turbulent cascade operates in compressible hydrodynamic turbulence. In general, there is no conservative compressible cascade since the kinetic and internal energy reservoirs can exchange energy through pressure dilatation. Moreover, statisti...
[Phys. Rev. E 100, 043116] Published Thu Oct 31, 2019
Author(s): Debasish Das and Eric Lauga
The plethora of swimming techniques developed by bacteria suggest that how they swim depends on their environment, size, and shape. This study provides interesting insights into this problem. The authors theoretically and numerically investigate the transition from swimming to a surface-bound state observed in unusual gigantic bacteria.
[Phys. Rev. E 100, 043117] Published Thu Oct 31, 2019
Author(s): Catherine Spurin, Tom Bultreys, Branko Bijeljic, Martin J. Blunt, and Samuel Krevor
The use of Darcy's law to describe steady-state multiphase flow in porous media has been justified by the assumption that the fluids flow in continuously connected pathways. However, a range of complex interface dynamics have been observed during macroscopically steady-state flow, including intermit...
[Phys. Rev. E 100, 043115] Published Tue Oct 29, 2019
Author(s): S. Blanco-Trejo, M. A. Herrada, A. M. Gañán-Calvo, and José M. Montanero
We study theoretically the influence of viscoelasticity on the steady cone-jet mode of electrospray for small stress relaxation times. For this purpose, we numerically integrate the leaky-dielectric model together with the Oldroyd-B constitutive relationship and calculate both the base flow and line...
[Phys. Rev. E 100, 043114] Published Mon Oct 28, 2019
Author(s): Ö. D. Gürcan, Shaokang Xu, and P. Morel
Reduced models, mirroring self-similar, fractal nature of two-dimensional turbulence, are proposed, using logarithmic spiral chains, which provide a natural generalization of shell models to two dimensions. In a turbulent cascade, where each step can be represented by a rotation and a scaling of the...
[Phys. Rev. E 100, 043113] Published Fri Oct 25, 2019