Physical Review Fluids
Leading-edge flow reattachment and the lateral static stability of low-aspect-ratio rectangular wings
Author(s): Thomas Linehan and Kamran Mohseni
An experimental study of low-aspect-ratio rectangular wings in cross flow shows that the reorganization of vortex flow on the wing plays a key role in initiating “roll stall” at angles of attack of sustained/increasing lift.
[Phys. Rev. Fluids 2, 113901] Published Mon Nov 13, 2017
Author(s): Peter J. Schmid, Miguel Fosas de Pando, and N. Peake
Many fluid systems consisting of an assembly of multiple but identical elements exhibit collective and synchronized motion involving groups of locked-in units. A computational framework for this type of fluid system with examples from hydrodynamic stability and turbomachinery is presented.
[Phys. Rev. Fluids 2, 113902] Published Mon Nov 13, 2017
Author(s): Mairi E. McKay, Moritz Linkmann, Daniel Clark, Adam A. Chalupa, and Arjun Berera
Three commonly used methods of energy injection are tested in simulations of homogeneous, incompressible magnetohydrodynamic turbulence without a mean magnetic field, showing, among other things, that the cross helicity is sensitive to the forcing function.
[Phys. Rev. Fluids 2, 114604] Published Mon Nov 13, 2017
Author(s): Bibin M. Jose and Thomas Cubaud
Experiments with immersed drops spreading on a surface or with two drops coalescing find that the contact diameter obeys a power law in time and in the internal and external viscosities.
[Phys. Rev. Fluids 2, 111601(R)] Published Fri Nov 10, 2017
Author(s): T. G. Fai, R. Kusters, J. Harting, C. H. Rycroft, and L. Mahadevan
Vesicle motion through a narrow channel with fluid resistance is studied with lubrication theory and lattice Boltzman simulations. We find two dimensionless parameters that characterize the motion and that multistable dynamics, in which a vesicle may move in either direction, are possible.
[Phys. Rev. Fluids 2, 113601] Published Fri Nov 10, 2017
Author(s): Blaise Delmotte, Aleksandar Donev, Michelle Driscoll, and Paul Chaikin
A simple continuum model to study the fingering instability in systems of micro-particles rotating parallel to a floor is developed. Analytical results are in agreement with the simulations and experiments, and are used to extract the physical mechanisms that trigger the instability.
[Phys. Rev. Fluids 2, 114301] Published Fri Nov 10, 2017
Author(s): Yasufumi Horimoto and Susumu Goto
Laboratory experiments of turbulence of non-Newtonian fluids reveal that the fully developed turbulence of Newtonian fluids in a precessing sphere is sustained by an energy cascading process.
[Phys. Rev. Fluids 2, 114603] Published Fri Nov 10, 2017
Author(s): Henry Shum and Julia M. Yeomans
Scattering trajectories for a swimmer interacting with a particle are simulated in Stokes flow, varying the size of the particle from much smaller than to much larger than the swimmer. The particle deflects the swimmer’s path, which can lead to a larger particle having a larger net displacement.
[Phys. Rev. Fluids 2, 113101] Published Thu Nov 09, 2017
Author(s): Elise E. Wright, David H. Richter, and Diogo Bolster
The role of incomplete mixing through an idealized two-dimensional heterogeneous porous medium is studied using a Lagrangian reactive particle tracking method. Velocity-gradient-based flow deformation metrics are considered and connections are made to conservative transport.
[Phys. Rev. Fluids 2, 114501] Published Wed Nov 08, 2017
Author(s): Natalia Shmakova, Evgeny Ermanyuk, and Jan-Bert Flór
Higher harmonic internal waves are generated at wave intersections and critical points of oscillating bodies, with higher amplitudes at steeper slopes and amplitude increase due to focusing for axisymmetric bodies. The horizontal structure of the nth harmonic corresponds to multipole order 2n.
[Phys. Rev. Fluids 2, 114801] Published Tue Nov 07, 2017
Author(s): Alexandre Cameron, Alexandros Alexakis, and Marc-Étienne Brachet
Kolmogorov’s theory gives predictions for the inertial scales of turbulent flows but not for the large scales. Direct numerical simulations and analytic derivation are used to investigate the spatiotemporal properties of large scales for flow solutions of Navier-Stokes and truncated Euler equations.
[Phys. Rev. Fluids 2, 114602] Published Mon Nov 06, 2017