Physical Review Fluids
Lean premixed reacting flows with swirl and wall-separation zones in a contracting open circular chamber
Author(s): Zvi Rusak, Yuxin Zhang, Jung J. Choi, and Shixiao Wang
A model problem of low-Mach number lean premixed reacting swirling flows with wall-separation zones in a contracting open chamber is studied. A theoretical feasibility for a technology of swirl-assisted combustion where the reaction zone is supported by a wall-separation zone is established.
[Phys. Rev. Fluids 3, 113201] Published Tue Nov 06, 2018
Author(s): Gigi Lin, John M. Frostad, and Gerald G. Fuller
Thin-film experiments with an interferometric apparatus show an absence of a strong relationship between interfacial elasticity and liquid entrainment in thin foam films, which can affect rational design of aesthetic and tactile properties in foaming consumer products.
[Phys. Rev. Fluids 3, 114001] Published Tue Nov 06, 2018
Temperature gradient induced double stabilization of the evaporation front within a drying porous medium
Author(s): N. Vorhauer, E. Tsotsas, and M. Prat
The flow of water vapor against temperature gradients naturally occurring in drying of porous media leads to condensation and simultaneous gas-liquid invasion of pore space. This phenomenon is studied with a model porous medium in a microfluidic device and a pore network model of drying and imbibition.
[Phys. Rev. Fluids 3, 114201] Published Tue Nov 06, 2018
Author(s): D. Lunz and P. D. Howell
Motivated by plasma particles impacting a liquid-metal divertor, an analysis is performed to investigate how a liquid’s free surface is deflected by a moving applied pressure. It is found that the plasma can be swept up and down the liquid in order to spread the heat load, however, this may induce dangerously large deflections.
[Phys. Rev. Fluids 3, 114801] Published Tue Nov 06, 2018
Author(s): Robert H. Davis and Alexander Z. Zinchenko
Hydrophobic particles are selectively separated from aqueous suspension by a novel oil-in-water binder. The collection efficiency is predicted in this work by a hydrodynamic trajectory analysis, and shown to be greatly enhanced by water permeation through the oil layer.
[Phys. Rev. Fluids 3, 113601] Published Thu Nov 01, 2018
Author(s): Alexandros Alexakis
An investigation of how large-scale flow is affected by changes in the properties of small-scale flows, the layer thickness, and viscosity is presented.
[Phys. Rev. Fluids 3, 114601] Published Thu Nov 01, 2018
Author(s): Yogesh Jethani, Kamal Kumar, A. Sameen, and Manikandan Mathur
Local stability equations are solved along closed fluid particle trajectories in the cylinder wake for Reynolds numbers in the range of 50 to 300. A bifurcation is shown to occur at Re≈250 and is argued to be related to the emergence of the well-known mode-B secondary instability.
[Phys. Rev. Fluids 3, 103902] Published Wed Oct 31, 2018
Author(s): Linlin Fei, Andrea Scagliarini, Andrea Montessori, Marco Lauricella, Sauro Succi, and Kai H. Luo
We further develop a two-range pseudopotential Lattice Boltzmann method for soft flowing systems using tunable surface tension and viscosity ratio. It is applicable to multicomponent fluids with a viscosity-independent disjoining pressure, a key to the microfluidic design of new porous materials.
[Phys. Rev. Fluids 3, 104304] Published Wed Oct 31, 2018
Law of the wall for small-scale streamwise turbulence intensity in high-Reynolds-number turbulent boundary layers
Author(s): B. Ganapathisubramani
Following the dimensional analysis approach of previous works, a law-of-the-wall is proposed for small-scale fluctuations in turbulent wall-flow. Experimental data shows that this universal scaling law extends across almost the entire wall-layer and exhibits a logarithmic trend in the outer region.
[Phys. Rev. Fluids 3, 104607] Published Wed Oct 31, 2018
Author(s): Benjamin Marchetti, Veronica Raspa, Anke Lindner, Olivia du Roure, Laurence Bergougnoux, Élisabeth Guazzelli, and Camille Duprat
A flexible fiber settling in a viscous fluid deforms and reorients to adopt eventually a more or less pronounced “U” shape, regardless of its initial configuration. Three different regimes depending on the relative magnitude of gravitational and elastic forces are identified.
[Phys. Rev. Fluids 3, 104102] Published Tue Oct 30, 2018
Author(s): Wenli Di, Zehui Zhang, Lin Li, Kejun Lin, Jun Li, Xiaoguang Li, Bernard P. Binks, Xiaopeng Chen, and Duyang Zang
Experiments shows that with increasing sound intensity, an acoustically levitated drop buckles into a bowl shape and experiences a drastic expansion and closure, leading to the formation of an air bubble. This is attributed to the enhanced suction effect at the film rim due to the occurrence of resonance with sound field.
[Phys. Rev. Fluids 3, 103606] Published Mon Oct 29, 2018
Author(s): N. B. Speirs, M. M. Mansoor, R. C. Hurd, S. I. Sharker, W. G. Robinson, B. J. Williams, and T. T. Truscott
An experimental study shows that splash formation is not reduced when spheres fall into water with a layer of soap bubbles on top. Instead, the bubble layer causes entrained air cavities to form at lower impact velocities. Results also show that the surfactant causes cavity formation to become radius dependent in cases where there is no bubble layer.
[Phys. Rev. Fluids 3, 104004] Published Mon Oct 29, 2018
Author(s): Simon Mendez and Manouk Abkarian
Red blood cells are modeled by an axisymmetric ellipsoid of fixed shape with internal circulation in shear flow without inertia. When accounting for membrane in-plane elasticity the model predicts the expected behaviors of flipping with orbit selection, rolling, frisbeeing, kayaking, and swinging.
[Phys. Rev. Fluids 3, 101101(R)] Published Thu Oct 25, 2018
Author(s): Antoine Piedfert, Benjamin Lalanne, Olivier Masbernat, and Frédéric Risso
Shape-oscillating droplets rising in a liquid are simulated with insoluble surfactants adsorbed at their interface. Conditions are reported in which the average surface tension gradient induces a significant decrease of the rise velocity but does not impact the oscillation dynamics.
[Phys. Rev. Fluids 3, 103605] Published Thu Oct 25, 2018
Author(s): Adnan Morshed, Prashanta Dutta, Mohammad Robiul Hossan, and Robert Dillon
The electrodeformation of a bio-vesicle suspended in liquid media depends on the conductivity ratio of fluid and vesicle, applied electric field, membrane capacitive charging, and vesicle initial shape. Our theoretical study provides important insights on this complex fluid-structure interaction.
[Phys. Rev. Fluids 3, 103702] Published Wed Oct 24, 2018
Author(s): Jonasz Słomka, Alex Townsend, and Jörn Dunkel
Simulations predict that a pendulum immersed in an active fluid oscillates faster than in a passive fluid due to a reduction of the fluid inertia. The decrease in inertia is mediated by topological defects in the stress field, which can effectively decouple the bulk flow dynamics from the pendulum.
[Phys. Rev. Fluids 3, 103304] Published Mon Oct 22, 2018
Author(s): Véronique Chireux, Matthieu Protat, Frédéric Risso, Thierry Ondarçuhu, and Philippe Tordjeman
Atomic Force Microscope observations find that two drops of radii 0.7 to 70 micrometers jump to contact when separated by a distance that scales as (HReq/γ)1/3 for small drops and as (H/γ)1/2 for larger drops.
[Phys. Rev. Fluids 3, 102001(R)] Published Fri Oct 19, 2018
Electrokinetics of a particle attached to a fluid interface: Electrophoretic mobility and interfacial deformation
Author(s): Michael Eigenbrod, Florian Bihler, and Steffen Hardt
The electrophoretic mobility of a particle at the interface between two fluids is computed. For thin Debye layers, the Smoluchowki mobility is recovered. Generally, the mobility depends on the contact angle between the fluids and the particle. The interfacial deformation is also calculated.
[Phys. Rev. Fluids 3, 103701] Published Fri Oct 19, 2018
Author(s): D. Reholon and S. Ghaemi
We perform drag force and particle tracking velocimetry measurements on a body-of-revolution coated with a superhydrophobic layer for Re between 5×105 and 1.5×106. As Re increases, drag reduction decreases, and a full plastron becomes isolated air bubbles as thin menisci.
[Phys. Rev. Fluids 3, 104003] Published Thu Oct 18, 2018
Author(s): Hridesh Kedia, Dustin Kleckner, Martin W. Scheeler, and William T. M. Irvine
The analog of hydrodynamic helicity in superfluids is zero for all flows. A semiclassical limit is found in the link and writhe of bundles of superfluid vortices. Numerical simulations show that the dynamics of semiclassical helicity closely resemble those seen in experiments in viscous fluids.
[Phys. Rev. Fluids 3, 104702] Published Thu Oct 18, 2018