Latest papers in fluid mechanics
Author(s): Carole Planchette, Francesco Marangon, Wen-Kai Hsiao, and Günter Brenn
Asymmetric liquid ligaments typically produced by inkjet printing may recoil or a drop may pinch off. Scaling laws are provided for these two competing processes, and it is shown that long and short ligaments experience different pinch-off regimes.
[Phys. Rev. Fluids 4, 124004] Published Thu Dec 19, 2019
Author(s): B. Zhang, Y. Ling, P.-H. Tsai, A.-B. Wang, S. Popinet, and S. Zaleski
The short-term falling dynamics of a dripping water drop is studied by simulation and experiment. The pinching dynamics introduces a nonlinear multimode oscillation. A complex transient flow around the drop is induced by the interaction between the falling motion and the shape oscillation.
[Phys. Rev. Fluids 4, 123604] Published Wed Dec 18, 2019
Author(s): Yuan Yao and Jesse Capecelatro
The role of electrohydrodynamics on the generation of atmospheric turbulence is studied theoretically and numerically. A nonlinear feedback loop is identified whereby charged aerosols self-induce an electric field, resulting in a body force on the ionized air, augmenting the atmospheric turbulence.
[Phys. Rev. Fluids 4, 123701] Published Wed Dec 18, 2019
Author(s): Y. Zhou, P.-Y. Lagrée, S. Popinet, P. Ruyer, and P. Aussillous
Experiments and a two-phase continuum model are used to study how gas flow enhances silo discharge. A modified Hagen-Beverloo law is proposed, taking into account the gas flow rate, the particle size, and the silo and orifice geometry.
[Phys. Rev. Fluids 4, 124305] Published Wed Dec 18, 2019
Author(s): John Kaminsky, Joe Klewicki, and Björn Birnir
We compare the stochastic closure theory (SCT) to the Townsend-Perry constants as estimated from measurements in the Flow Physic Facility (FPF) at the University of New Hampshire. First, we explain the derivation of the Townsend-Perry constants, which were originally formulated by Meneveau and Marus...
[Phys. Rev. E 100, 061101(R)] Published Mon Dec 16, 2019
Author(s): E. N’Gouamba, J. Goyon, and P. Coussot
Experiments show that the solid-liquid transition of yield stress fluids (emulsions, gels, foams, suspensions, etc.) is associated with the breakage (collapse) of a basic elastic network for a critical deformation, while progressively larger additional elastoplastic deformations take place in the system up to yielding.
[Phys. Rev. Fluids 4, 123301] Published Mon Dec 16, 2019
Author(s): Lebo Molefe and Ivo R. Peters
A vapor bubble collapsing near a solid boundary in a liquid produces a liquid jet that points toward the boundary. The direction of this jet has been studied for boundaries such as flat planes and parallel walls enclosing a channel. Extending these investigations to enclosed polygonal boundaries, we...
[Phys. Rev. E 100, 063105] Published Fri Dec 13, 2019
Integral model for multiple forced plumes arranged around a circle in a linearly stratified environment
Author(s): Zhiguo He and Yingzhong Lou
An integral model is developed to predict the mixing of multiple forced plumes evenly spaced around a circle in a stratified environment, e.g., buoyant plumes in nature. The model reasonably captures the significant plume boundary distortion caused by plume interactions at the touching height.
[Phys. Rev. Fluids 4, 123501] Published Fri Dec 13, 2019
Author(s): Walter Tewes, Markus Wilczek, Svetlana V. Gurevich, and Uwe Thiele
Using analytical and numerical methods we examine a solid substrate withdrawn from a liquid bath. After withdrawal the substrate may be macroscopically dry or coated homogeneously by a liquid film. We show that a regular liquid ridge pattern oriented parallel to the meniscus can also be deposited.
[Phys. Rev. Fluids 4, 123903] Published Fri Dec 13, 2019
Author(s): A. R. Piriz, S. A. Piriz, and N. A. Tahir
The linear theory of the incompressible Rayleigh-Taylor instability in elastic-plastic solid slabs is developed on the basis of the simplest constitutive model consisting in a linear elastic (Hookean) initial stage followed by a rigid-plastic phase. The slab is under the action of a constant acceler...
[Phys. Rev. E 100, 063104] Published Thu Dec 12, 2019
Author(s): Zaiyi Shen and Juho S. Lintuvuori
When squirmer type swimmers sediment on a flat surface, the near field hydrodynamic interactions lead to the formation of small spinners at low concentrations. Higher surface coverage results in a polar order of the swimmers and a particle vortex is observed when confined by a circular wall.
[Phys. Rev. Fluids 4, 123101] Published Thu Dec 12, 2019
Author(s): Min Y. Pack, Angela Yang, Antonio Perazzo, Boyang Qin, and Howard A. Stone
Experiments show that the addition of polymers in droplets enhances the droplet rebound effect when bouncing on a thin film of air.
[Phys. Rev. Fluids 4, 123603] Published Thu Dec 12, 2019
Author(s): T. Bickel, J.-C. Loudet, G. Koleski, and B. Pouligny
The Stokes flow of a submerged jet directed toward a free interface is investigated theoretically. The presence of a minute amount of surface-active agents drastically modifies the hydrodynamic response of the interface.
[Phys. Rev. Fluids 4, 124002] Published Thu Dec 12, 2019
Author(s): Gerald J. Wang, Angelo Damone, Francesco Benfenati, Pietro Poesio, Gian Paolo Beretta, and Nicolas G. Hadjiconstantinou
At the nanoscale, and in particular in the presence of slip, hydrodynamic bending of interfaces between immiscible liquids becomes negligible. The dynamic contact angle is then governed by the Molecular Kinetic Theory (MKT) of Blake and collaborators.
[Phys. Rev. Fluids 4, 124203] Published Wed Dec 11, 2019
Author(s): Ehud Yariv
Asymptotic methods and conformal mappings are used to study mass or heat transport from a particle that is subject to a weak flow.
[Phys. Rev. Fluids 4, 124503] Published Wed Dec 11, 2019
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): Franziska Henrich, Dorota Linke, Hans Martin Sauer, Edgar Dörsam, Steffen Hardt, Hans-Jürgen Butt, and Günter K. Auernhammer
The interaction of pinning and surfactant-induced changes of dynamic contact angles on receding contact lines is studied. With increasing surfactant concentration the surfactant-induced effects dominate over pinning effects. This behavior is correlated to the emptying of the surface structures.
[Phys. Rev. Fluids 4, 124202] Published Mon Dec 09, 2019
Role of large-scale advection and small-scale turbulence on vertical migration of gyrotactic swimmers
Author(s): C. Marchioli, H. Bhatia, G. Sardina, L. Brandt, and A. Soldati
The role of large-scale motions and small-scale turbulence on rising of small bottom-heavy swimmers is examined via high Reynolds number direct numerical simulation of turbulent free-surface flow. The swimmers’ rising efficiency is quantified via a new timescale that combines the stability number and the Kolmogorov timescale.
[Phys. Rev. Fluids 4, 124304] Published Mon Dec 09, 2019
Potential-core closing of temporally developing jets at Mach numbers between 0.3 and 2: Scaling and conditional averaging of flow and sound fields
Author(s): Christophe Bogey and Pierre Pineau
Using direct numerical simulation, the potential-core closing of temporally developing round jets at Mach numbers between 0.3 and 2 is shown to radiate strong axisymmetric acoustic waves in the downstream direction. The Mach number dependence and the generation mechanism of these waves are revealed.
[Phys. Rev. Fluids 4, 124601] Published Mon Dec 09, 2019
Author(s): Shancong Tao and Yi Zhou
A numerical study confirms that by using multiscale structures, turbulence with a wider range of scales can be generated. However, the multiscale-generated turbulence may not have a long-lasting memory and can eventually forget its multiscale initial conditions.
[Phys. Rev. Fluids 4, 124602] Published Mon Dec 09, 2019