Latest papers in fluid mechanics
[Phys. Rev. Fluids 3, 060001] Published Wed Jun 13, 2018
Author(s): Alexis Bougouin and Laurent Lacaze
The collapse of a granular column in a fluid shows that both the dynamics and the deposit shape depend on the aspect ratio, Stokes number, and grain-fluid density ratio. Classification of flow regimes and characterization of the associated dynamics are proposed through an experimental investigation.
[Phys. Rev. Fluids 3, 064305] Published Wed Jun 13, 2018
Author(s): Murali-Girija Mithun, Phoevos Koukouvinis, and Manolis Gavaises
A fully compressible three-phase cavitation model is developed to study the interaction between the cavitation and primary atomization. The simulations reveal that the developing cavitation condition with cyclic air entrainment is the most favourable condition for primary atomization.
[Phys. Rev. Fluids 3, 064304] Published Tue Jun 12, 2018
Author(s): Jeffrey Tithof, Benjamin C. Martell, and Douglas H. Kelley
Two-dimensional flow is often approximated by driving thin fluid layers electromagnetically. By comparing three common experimental configurations, it is shown that the single-layer and immiscible configurations minimize out-of-plane flow over a wider range of Reynolds numbers than miscible configurations.
[Phys. Rev. Fluids 3, 064602] Published Tue Jun 12, 2018
Author(s): Muralikrishnan Gopalakrishnan Meena, Aditya G. Nair, and Kunihiko Taira
A network community-based reduced-order model is developed to capture key interactions among coherent structures in high-dimensional unsteady vortical flows. The present approach is data-inspired and founded on network-theoretic techniques to identify important vortical communities that are comprise...
[Phys. Rev. E 97, 063103] Published Mon Jun 11, 2018
Author(s): Anita A. Dey, Yahya Modarres-Sadeghi, and Jonathan P. Rothstein
Elastic flow instabilities in the wake of a flexible cylinder can drive the motion of the cylinder, resulting in 1D and 2D oscillations. The time variation of the flow field and the state of stress in the fluid are shown using particle image tracking and flow-induced birefringence images.
[Phys. Rev. Fluids 3, 063301] Published Mon Jun 11, 2018
Author(s): Grégoire Bongrand and Peichun Amy Tsai
When a more mobile fluid displaces another immiscible one in a porous medium, viscous fingering propagates with a partial sweep, which hinders oil recovery and soil remedy. We experimentally investigate the feasibility of tuning such fingering propagation in a nonuniform narrow passage with a radial...
[Phys. Rev. E 97, 061101(R)] Published Fri Jun 08, 2018
Internal waves in sheared flows: Lower bound of the vorticity growth and propagation discontinuities in the parameter space
Author(s): Federico Fraternale, Loris Domenicale, Gigliola Staffilani, and Daniela Tordella
This study provides sufficient conditions for the temporal monotonic decay of enstrophy for two-dimensional perturbations traveling in the incompressible, viscous, plane Poiseuille, and Couette flows. Extension of Synge's procedure [J. L. Synge, Proc. Fifth Int. Congress Appl. Mech. 2, 326 (1938); S...
[Phys. Rev. E 97, 063102] Published Fri Jun 08, 2018
Rheology of dense granular flows in two dimensions: Comparison of fully two-dimensional flows to unidirectional shear flow
Author(s): Ashish Bhateja and Devang V. Khakhar
Numerical simulations of dense granular flows in three different planar geometries find that the μ-I scaling for the local viscosity is found to be valid for each geometry, but the data for the three geometries do not collapse to a single curve.
[Phys. Rev. Fluids 3, 062301(R)] Published Fri Jun 08, 2018
Author(s): Alexander Morozov, Davide Marenduzzo, and Ronald G. Larson
In this paper, we report an inertial instability that occurs in electro-osmotically driven channel flows. We assume that the charge motion under the influence of an externally applied electric field is confined to a small vicinity of the channel walls that, effectively, drives a bulk flow through a ...
[Phys. Rev. Fluids 3, 063702] Published Fri Jun 08, 2018
Influence of a thin compressible insoluble liquid film on the eddy currents generated by interacting surface waves
Author(s): Vladimir M. Parfenyev and Sergey S. Vergeles
Crossed surface waves generate eddy currents near the fluid surface owing to hydrodynamic nonlinearity. We studied how these currents penetrate into the fluid bulk and showed that a thin compressible insoluble liquid film presented on the fluid surface increases their intensity.
[Phys. Rev. Fluids 3, 064702] Published Fri Jun 08, 2018
Author(s): A. M. P. Boelens, A. Latka, and J. J. de Pablo
At atmospheric pressure, a droplet impacting on a surface produces a splash. Reducing the ambient pressure suppresses this splash. The pressure effect is not well understood and this is the first study to present an in-depth comparison between various theoretical splashing models and simulations.
[Phys. Rev. Fluids 3, 063602] Published Thu Jun 07, 2018
Electrohydrodynamic ionic wind, force field, and ionic mobility in a positive dc wire-to-cylinders corona discharge in air
Author(s): Nicolas Monrolin, Olivier Praud, and Franck Plouraboué
Particle image velocimetry of ionic wind produced by a positive dc corona in air is used to evaluate lift force, and results are consistent with a general theoretical expression previously found for net momentum transfer. Momentum transfer efficiency is found to be sensitive to the electrode aerodynamic wake and the electric field orientation.
[Phys. Rev. Fluids 3, 063701] Published Thu Jun 07, 2018
Author(s): Xiuxiu Lyu, Shucheng Pan, Xiangyu Hu, and Nikolaus A. Adams
With the Euler-Lagrangian coupled method we simulate homogeneous nucleation cavitation induced by shock reflection in a microchannel. Nucleation is found to occur in three stages: energy deposition, generation, and growth. Initial generation time is not found to depend strongly on shock intensity.
[Phys. Rev. Fluids 3, 064303] Published Thu Jun 07, 2018
Author(s): Fabian Reuter and Robert Mettin
A high-speed method for time-resolved measurements of wall shear rates providing microscopic resolution is presented. The wall shear rates produced by a single, collapsing cavitation bubble are studied.
[Phys. Rev. Fluids 3, 063601] Published Wed Jun 06, 2018
Author(s): Jacob Keller, Praveen Kumar, and Krishnan Mahesh
Results of a high-fidelity large eddy simulation are used to compute the far-field sound that results from the unsteady loading of a propeller operating at design condition. High levels of unsteadiness at the blade tip account for the majority of far-field sound.
[Phys. Rev. Fluids 3, 064601] Published Wed Jun 06, 2018
Author(s): S. Pasche, F. Avellan, and F. Gallaire
The dynamics of the helical vortex breakdown has revealed a Ruelle-Takens-Newhouse route to chaos coming from the nonlinear interactions of pure hydrodynamic modes. Global stability analysis, Fourier series decomposition, and time series analysis have been used to shed light on the dynamical states.
[Phys. Rev. Fluids 3, 064701] Published Wed Jun 06, 2018
Author(s): Luis Blay Esteban, John Shrimpton, and Bharathram Ganapathisubramani
Trajectories of N-sided polygons falling in quiescent media are used to measure the edge effect on the descent. A new length scale is proposed to estimate the equivalent dimensionless numbers. This allows use of the original phase diagram for disks and reconciles the effects of particle shape.
[Phys. Rev. Fluids 3, 064302] Published Tue Jun 05, 2018