Physical Review Fluids
Author(s): Pedro S. Volpiani, Matteo Bernardini, and Johan Larsson
The effects of wall thermal conditions on the canonical case of an impinging shock wave interacting with a turbulent boundary layer is an under-explored topic. Direct numerical simulations are used to study the flow properties of supersonic shock/boundary-layer interactions with distinct wall thermal conditions and shock angles.
[Phys. Rev. Fluids 3, 083401] Published Wed Aug 22, 2018
Author(s): Evan H. Anders, Benjamin P. Brown, and Jeffrey S. Oishi
A mechanism for rapidly achieving thermal relaxation in high-Pe convective simulations is studied in the context of Rayleigh-Bénard convection. It achieves statistically similar states to standard timestepping and saves up to an order of magnitude in computational time for the problems studied.
[Phys. Rev. Fluids 3, 083502] Published Tue Aug 21, 2018
Author(s): Seong Jin Kim, Seungho Kim, and Sunghwan Jung
When a dog accelerates its tongue to lap water, a water column is created and pinches off close to the tongue. Physical experiments and a theoretical model of accelerating a solid sphere from a liquid bath elucidate the mechanism of the liquid-column formation and pinch-off.
[Phys. Rev. Fluids 3, 084001] Published Tue Aug 21, 2018
Author(s): S. Başbuğ, G. Papadakis, and J. C. Vassilicos
Fractal impellers can lead to a considerably shorter mixing time compared to regular impellers. This is explained by the differences in characteristics of flow and scalar fields. Moreover, a mathematical model is proposed which can approximate the decay rate of the passive scalar fluctuations.
[Phys. Rev. Fluids 3, 084502] Published Tue Aug 21, 2018
Author(s): Nisat Nowroz Anika, Lyazid Djenidi, and Sedat Tardu
Implementation of a bypass laminar-to-turbulent transition is explored. We show that our method, by bypassing linear exponential growth, can induce high mixing capacity localized turbulence in a laminar channel flow at low Re. An on-demand mixing enhancement in laminar channel flow is proposed.
[Phys. Rev. Fluids 3, 084604] Published Tue Aug 21, 2018
Author(s): Rodica Borcia, Michael Bestehorn, Sebastian Uhlig, Matthieu Gaudet, and Harald Schenk
An original mathematical tool suitable for describing fluid dynamics in micropumps induced by transverse forced vibrations of an elastic beam is presented. The model could also be used in designing engineering software for micromachinery applications.
[Phys. Rev. Fluids 3, 084202] Published Mon Aug 20, 2018
Reciprocal theorem for the prediction of the normal force induced on a particle translating parallel to an elastic membrane
Author(s): Abdallah Daddi-Moussa-Ider, Bhargav Rallabandi, Stephan Gekle, and Howard A. Stone
A solid sphere translating tangent to an elastic membrane is subject to a lift force perpendicular to its direction of motion. This effect is attributed to an elastohydrodynamic coupling that arises from the breaking of flow reversal symmetry induced by elastic deformation.
[Phys. Rev. Fluids 3, 084101] Published Fri Aug 17, 2018
Author(s): Emre Turkoz, SeungYeon Kang, Luc Deike, and Craig B. Arnold
The process of blister-actuated laser-induced forward transfer (BA-LIFT) results in focused jets which are thinner and faster than regular jets.
[Phys. Rev. Fluids 3, 082201(R)] Published Wed Aug 15, 2018
Observation of a link between energy dissipation rate and oscillation frequency of the large-scale circulation in dry and moist Rayleigh-Bénard turbulence
Author(s): Dennis Niedermeier, Kelken Chang, Will Cantrell, Kamal Kant Chandrakar, David Ciochetto, and Raymond A. Shaw
An investigation of both the large- and small-scale flow properties of moist and cloudy, turbulent Rayleigh-Bénard convection suggests that the large scale circulation is insensitive to phase composition/interfacial physics; rather, it depends only on the strength of the turbulence.
[Phys. Rev. Fluids 3, 083501] Published Wed Aug 15, 2018
Dynamics of paramagnetic and ferromagnetic ellipsoidal particles in shear flow under a uniform magnetic field
Author(s): Christopher A. Sobecki, Jie Zhang, Yanzhi Zhang, and Cheng Wang
We theoretically and numerically study the effects of a uniform magnetic field on the dynamics of ellipsoidal ferromagnetic and paramagnetic particles in a simple shear flow at low Reynolds number. With numerical simulations we further illustrate their lateral migration in wall-bounded shear flows.
[Phys. Rev. Fluids 3, 084201] Published Tue Aug 14, 2018
Author(s): Rausan Jewel, Andreea Panaitescu, and Arshad Kudrolli
The drag experienced by a spherical intruder settling through a medium composed of transparent granular hydrogels and water is measured as a function of its speed and depth. Internal visualization of the medium shows its flow to be localized around the advancing intruder.
[Phys. Rev. Fluids 3, 084303] Published Tue Aug 14, 2018
Author(s): Yoshiyuki Tagawa and Ivo R. Peters
The collapse of a vapor bubble in a corner generates a jet whose direction depends on the corner opening angle and bubble position. Experimental data is found to agree well with a potential flow model that gives analytical solutions for a family of corner opening angles.
[Phys. Rev. Fluids 3, 081601(R)] Published Mon Aug 13, 2018
Author(s): Michael Sinhuber, Joseph G. Ballouz, and Nicholas T. Ouellette
Experimental observations of the pair correlation function of small inertial particles in a turbulent flow of dilute polymer solutions shows that particle clustering increases with the concentration of polymers, possibly reflecting a reduction of vorticity relative to straining.
[Phys. Rev. Fluids 3, 082602(R)] Published Thu Aug 09, 2018
Author(s): Sualeh Khurshid, Diego A. Donzis, and K. R. Sreenivasan
Numerical simulations of isotropic turbulence find that the energy spectrum in the dissipation range cannot be described by a single exponential for Rλ>20, and that this effect is associated with intermittent energy transfer.
[Phys. Rev. Fluids 3, 082601(R)] Published Wed Aug 08, 2018
Author(s): Luis Cueto-Felgueroso, Xiaojing Fu, and Ruben Juanes
Liquid-vapor phase change is simulated in a porous medium, using a diffuse-interface model and the van der Waals equation of state. The role of wettability and pore space geometry on phase separation and on the propagation of evaporation fronts is investigated.
[Phys. Rev. Fluids 3, 084302] Published Wed Aug 08, 2018
Author(s): S. Lejeune, T. Gilet, and L. Bourouiba
Liquid sheet fragmentation is ubiquitous in nature and may shape phenomena such as the rain-induced propagation of foliar diseases. An experimental study investigates the formation and fragmentation of an asymmetric liquid sheet upon impact of a drop close to the edge of a solid substrate.
[Phys. Rev. Fluids 3, 083601] Published Tue Aug 07, 2018
Evolution of anisotropy in direct numerical simulations of MHD turbulence in a strong magnetic field on elongated periodic domains
Author(s): X. M. Zhai and P. K. Yeung
Time development (from top to bottom) of vortical structures (in red) in background of low vorticity (blue) in planar cross-sections of turbulence subjected to magnetic field on an elongated domain of aspect ratio 8, at 16384×20482 grid resolution.
[Phys. Rev. Fluids 3, 084602] Published Tue Aug 07, 2018
Author(s): Kosuke Osawa and Javier Jiménez
The effects of the ambiguity in the definition of the Reynolds stresses to the coherent structures in wall turbulence are studied. It is confirmed that sweeps, ejections, and rollers are robust features of the flow.
[Phys. Rev. Fluids 3, 084603] Published Tue Aug 07, 2018
Author(s): F. H. H. Al Mukahal, B. R. Duffy, and S. K. Wilson
The general parametric solution for the steady unidirectional flow of a thin rivulet of a generalized Newtonian fluid is obtained and illustrated for Carreau and Ellis fluids. In particular, the solution is used to describe the behavior of a rivulet of a strongly shear-thinning Ellis fluid.
[Phys. Rev. Fluids 3, 083302] Published Mon Aug 06, 2018
Turbulent magnetohydrodynamic flow in a square duct: Comparison of zero and finite magnetic Reynolds number cases
Author(s): Vinodh Bandaru, Thomas Boeck, and Jörg Schumacher
The effect of finite magnetic Reynolds numbers (Rm∼102) on MHD flow in a square duct was studied using direct numerical simulations. The structure of the secondary mean flow is modified significantly and the streamwise anisotropy is strongly enhanced away from the boundary layers.
[Phys. Rev. Fluids 3, 083701] Published Mon Aug 06, 2018