Latest papers in fluid mechanics
Author(s): Lilian de Martín
Standing wave patterns can occur both in vibrated granular layers and pulsed fluidized beds. Although the different type of excitation results in a different definition of the driving parameters and instability curve, a theoretical study shows that the instability criterion in both systems is similar.
[Phys. Rev. Fluids 3, 124304] Published Wed Dec 19, 2018
Author(s): Francis H. Robertson and Gregory F. Lane-Serff
The effect of one obstacle on the drag on a second obstacle is measured for square obstacles in subcritical open channel flow. The lowest drag occurs when one obstacle is shielded directly behind another, and the largest drag occurs on a slightly upstream obstacle in near side-by-side arrangements.
[Phys. Rev. Fluids 3, 123802] Published Tue Dec 18, 2018
Author(s): Dhirendra Tiwari, Lionel Mercury, Marcel Dijkstra, Himanshu Chaudhary, and José Federico Hernández-Sánchez
The relaxation of a liquid drop in a Hele-Shaw cell is observed experimentally and then modeled successfully.
[Phys. Rev. Fluids 3, 124202] Published Tue Dec 18, 2018
Author(s): B. R. Duffy, S. K. Wilson, J. J. A. Conn, and K. Sefiane
The evolution of the shape (but not the position) of a long bubble or droplet in a self-rewetting system in a nonuniformly heated tube is shown to be driven entirely by Marangoni effects: a wide droplet widens (and ultimately fills the cross section of the tube), whereas a narrow droplet narrows.
[Phys. Rev. Fluids 3, 123603] Published Mon Dec 17, 2018
Hierarchical random additive model for the spanwise and wall-normal velocities in wall-bounded flows at high Reynolds numbers
Author(s): X. I. A. Yang, R. Baidya, Yu Lv, and I. Marusic
Both the spanwise and the vertical velocity components in high-Reynolds-number wall-bounded flows may be modeled via a random additive process. Evidence shows that a hierarchical, treelike structure exists for the spanwise velocity component.
[Phys. Rev. Fluids 3, 124606] Published Mon Dec 17, 2018
Author(s): Ryan McKeown, Rodolfo Ostilla-Mónico, Alain Pumir, Michael P. Brenner, and Shmuel M. Rubinstein
A novel breakdown mechanism is observed during the head-on collision of two vortex rings. The interacting cores locally flatten into extremely thin vortex sheets and split into smaller daughter filaments iteratively over two generations, leading to the rapid emergence of fine-scale vortices.
[Phys. Rev. Fluids 3, 124702] Published Mon Dec 17, 2018
Author(s): Andrea Armaroli, Debbie Eeltink, Maura Brunetti, and Jérôme Kasparian
An envelope equation to model the propagation of surface waves in deep viscous fluids is proposed. The dispersion relation comprising viscosity and surface tension is expressed as an operator and used to generalize the universal nonlinear Schrödinger equation and quantify nonlinear damping.
[Phys. Rev. Fluids 3, 124803] Published Mon Dec 17, 2018
Author(s): Akshay Bhatnagar, K. Gustavsson, B. Mehlig, and Dhrubaditya Mitra
We perform direct numerical simulations of a bidisperse suspension of heavy spherical particles in forced, homogeneous, and isotropic three-dimensional turbulence. We compute the joint distribution of relative particle distances and longitudinal relative velocities between particles of different ine...
[Phys. Rev. E 98, 063107] Published Thu Dec 13, 2018
Apparent slip and drag reduction for the flow over superhydrophobic and lubricant-impregnated surfaces
Author(s): Edoardo Alinovi and Alessandro Bottaro
The flow within microscopic indentations filled with a lubricant fluid is studied by varying viscosity ratio, surface tension, and lubricant-to-working-fluid volume fraction. This yields protrusion heights that readily quantify the drag reduction of a lubricant-impregnated microstructured surface.
[Phys. Rev. Fluids 3, 124002] Published Thu Dec 13, 2018
Author(s): Darwin Darakananda, André Fernando de Castro da Silva, Tim Colonius, and Jeff D. Eldredge
This works shows for the first time that an inexpensive ensemble of low-order vortex models can accurately capture the aerodynamics of a low Reynolds number separated flow, even when disturbed by gusts, when it assimilates measured surface pressures.
[Phys. Rev. Fluids 3, 124701] Published Thu Dec 13, 2018
Author(s): Jim Thomas and Ray Yamada
A new amplitude equation that captures the effect of arbitrary topography on surface waves is presented. It can be integrated more quickly than the fully nonlinear equations, while accurately capturing the wave dynamics.
[Phys. Rev. Fluids 3, 124802] Published Thu Dec 13, 2018
Author(s): Johannes Sachs, Konstantin I. Morozov, Oded Kenneth, Tian Qiu, Nico Segreto, Peer Fischer, and Alexander M. Leshansky
We theoretically and experimentally investigate low-Reynolds-number propulsion of geometrically achiral planar objects that possess a dipole moment and that are driven by a rotating magnetic field. Symmetry considerations (involving parity P̂ and charge conjugation Ĉ) establish correspondence betwe...
[Phys. Rev. E 98, 063105] Published Wed Dec 12, 2018
Experimental modulation and theoretical simulation of zonal oscillation for electrostatically levitated metallic droplets at high temperatures
Author(s): H. P. Wang, M. X. Li, P. F. Zou, X. Cai, L. Hu, and B. Wei
The second- and third-order zonal oscillations of metallic droplets at high temperatures beyond 2000 K were experimentally achieved by electrostatic levitation. To quantitatively describe the suspension stability of different metallic droplets, a stability factor model was proposed as a function of ...
[Phys. Rev. E 98, 063106] Published Wed Dec 12, 2018
Author(s): M. Couliou and R. Monchaux
We numerically investigate temporal aspects of turbulent spot spreading in plane Couette flow for transitional Reynolds numbers, focusing on streamwise spreading. From the topology of turbulent spots and associated large-scale flows, we propose a decomposition of the streamwise growth rate.
[Phys. Rev. Fluids 3, 123901] Published Wed Dec 12, 2018
Investigation of the phenomena occurring near the liquid–vapor interface during evaporation of water at low pressures
Author(s): Mohammad Amin Kazemi, David S. Nobes, and Janet A. W. Elliott
The three-dimensional flow generated below a liquid-vapor meniscus during low-pressure water evaporation is quantified with experiments using scanning particle image velocimetry and compared with an extensive numerical model. Results show how buoyancy effects in the liquid may suppress thermocapillary flows at the interface.
[Phys. Rev. Fluids 3, 124001] Published Wed Dec 12, 2018
Erratum: Scaling laws of top jet drop size and speed from bubble bursting including gravity and inviscid limit [Phys. Rev. Fluids <b>3</b>, 091601(R) (2018)]
Author(s): Alfonso M. Gañán-Calvo
[Phys. Rev. Fluids 3, 129901] Published Wed Dec 12, 2018
Author(s): Fabrizio Croccolo, Stefano Castellini, Frank Scheffold, and Alberto Vailati
Solid-solid phase transitions are commonly encountered at the atomic scale in alloys and in superatomic mesoscopic systems of colloidal particles. Here we investigate a solid-solid phase transition occurring at the macroscopic scale between lattices of liquid jets with different symmetries generated...
[Phys. Rev. E 98, 063104] Published Tue Dec 11, 2018
Optimal design of deterministic lateral displacement device for viscosity-contrast-based cell sorting
Author(s): Gökberk Kabacaoğlu and George Biros
Deterministic lateral displacement (DLD) is used to sort red blood cells (RBCs) by their mechanical properties. This enables rapid medical diagnosis of diseases such as malaria. A systematic way of discovering new DLD designs for efficient sorting of RBCs with similar mechanical properties is proposed.
[Phys. Rev. Fluids 3, 124201] Published Tue Dec 11, 2018
Electromagnetic field orientation and characteristics governed hydrodynamics within pendent droplets
Author(s): Purbarun Dhar, Vivek Jaiswal, and A. R. Harikrishnan
This article reports the dominant governing role played by the direction of electric and magnetic fields on the internal advection pattern and strength within salt solution pendent droplets. The literature shows that solutal advection drives circulation cells within salt based droplets, even in the ...
[Phys. Rev. E 98, 063103] Published Mon Dec 10, 2018
Apparent slip mechanism between two spheres based on solvent rheology: Theory and implication for the shear thinning of non-Brownian suspensions
Author(s): A. Vázquez-Quesada, Pep Español, and M. Ellero
The slip behavior observed experimentally between close spheres is described by an analytical model in terms of the apparent shear-thinning rheology of the solvent. The results compare well with experiments and bridge the hidden solvent shear-thinning theory for suspensions with slip-based models.
[Phys. Rev. Fluids 3, 123302] Published Mon Dec 10, 2018