Latest papers in fluid mechanics

Structure of wall-bounded flows at transcritical conditions

Physical Review Fluids - Fri, 03/30/2018 - 11:00

Author(s): Peter C. Ma, Xiang I. A. Yang, and Matthias Ihme

Direct numerical simulations of channel flow at transcritical conditions with density change in the flow field are conducted. We find a regime with useful semi-local scaling as well as streamwise velocity and energy spectrum scaling which support the attached eddy model at transcritical conditions.

[Phys. Rev. Fluids 3, 034609] Published Fri Mar 30, 2018

Buoyant miscible displacement flows in a nonuniform Hele-Shaw cell

Physical Review Fluids - Thu, 03/29/2018 - 11:00

Author(s): E. Walling, R. Mollaabbasi, and S. M. Taghavi

By modifying the geometry of a vertical Hele-Shaw cell—making it either converging or diverging—experimental and theoretical investigation shows that it is possible to control the stability of miscible buoyancy driven flows. This includes the promotion/inhibition of viscous fingering.

[Phys. Rev. Fluids 3, 034003] Published Thu Mar 29, 2018

Unsteady characteristics of a slat-cove flow field

Physical Review Fluids - Thu, 03/29/2018 - 11:00

Author(s): Kyle A. Pascioni and Louis N. Cattafesta

The slat flow field of a multi-element airfoil is experimentally studied. Mean turbulence statistics and phase-locked data link shear layer structures to narrowband peaks in the surface pressure spectra. Most notably, a bulk cove oscillation related to shear layer flapping is found.

[Phys. Rev. Fluids 3, 034607] Published Thu Mar 29, 2018

Dynamic domains of the Derviche Tourneur sodium experiment: Simulations of a spherical magnetized Couette flow

Physical Review Fluids - Thu, 03/29/2018 - 11:00

Author(s): E. J. Kaplan, H.-C. Nataf, and N. Schaeffer

A magnetized liquid sodium experiment and high-end numerical simulations are performed, both yielding similar magnetic signatures. Coherent flow structures are found to emerge from developed turbulence, some of which are related to linear instabilities of the mean flow.

[Phys. Rev. Fluids 3, 034608] Published Thu Mar 29, 2018

Immiscible three-dimensional fingering in porous media: A weakly nonlinear analysis

Physical Review Fluids - Wed, 03/28/2018 - 11:00

Author(s): Rodolfo Brandão, Eduardo O. Dias, and José A. Miranda

The immiscible three-dimensional (3D) radial viscous fingering problem in uniform porous media is studied. Linearly, algebraic growth of disturbances and the existence of regions of absolute stability are detected. On the nonlinear side, a basic mechanism leading to 3D tip-splitting is proposed.

[Phys. Rev. Fluids 3, 034002] Published Wed Mar 28, 2018

Nanoparticle motion on the surface of drying droplets

Physical Review Fluids - Wed, 03/28/2018 - 11:00

Author(s): Mingfei Zhao and Xin Yong

Transport and deposition of particles on the free surface of a drying droplet with a pinned contact line is studied by a multiphase lattice Boltzmann-Brownian dynamics method. The results reveal that both surface convection and interfacial confinement govern particle dynamics.

[Phys. Rev. Fluids 3, 034201] Published Wed Mar 28, 2018

Bubble deformations and segmented flows in corrugated microchannels at large capillary numbers

Physical Review Fluids - Wed, 03/28/2018 - 11:00

Author(s): Martin Sauzade and Thomas Cubaud

The angular shape and dynamics of bubbles passing through a series of microfluidic extensions and contractions are investigated at large capillary numbers. The relationship between individual bubble deformation and collective distortion of segmented flows is examined in nonlinear microgeometries.

[Phys. Rev. Fluids 3, 034202] Published Wed Mar 28, 2018

Double helix vortex breakdown in a turbulent swirling annular jet flow

Physical Review Fluids - Wed, 03/28/2018 - 11:00

Author(s): M. Vanierschot, M. Percin, and B. W. van Oudheusden

Double helical vortex breakdown is rarely observed in experiments and is mostly reported for laminar flows. A double helical breakdown structure in a turbulent annular jet is identified and its dynamics analyzed based on time-resolved tomographic particle image velocimetry measurements.

[Phys. Rev. Fluids 3, 034703] Published Wed Mar 28, 2018

Vortex coupling in trailing vortex-wing interactions

Physical Review Fluids - Wed, 03/28/2018 - 11:00

Author(s): C. Chen, Z. Wang, and I. Gursul

An investigation of trailing vortices shed from an upstream wing interacting with a flexible downstream wing reveals the formation of a counterrotating vortex pair. The incident vortex is subject to increased meandering as it interacts with the wing.

[Phys. Rev. Fluids 3, 034704] Published Wed Mar 28, 2018

Long-wave-instability-induced pattern formation in an evaporating sessile or pendent liquid layer

Physical Review Fluids - Tue, 03/27/2018 - 11:00

Author(s): Tao Wei and Fei Duan

The long-wave model accounting for gravity in evaporating layers shows that buoyancy has no influence on interfacial evolution, but it contributes to Marangoni-Rayleigh-Bénard convection in positive gravity and to Marangoni convection in negative gravity.

[Phys. Rev. Fluids 3, 034001] Published Tue Mar 27, 2018

Torque scaling in small-gap Taylor-Couette flow with smooth or grooved wall

Physical Review E - Mon, 03/26/2018 - 11:00

Author(s): Bihai Zhu, Zengqi Ji, Zhengkun Lou, and Pengcheng Qian

The torque in the Taylor-Couette flow for radius ratios η≥0.97, with smooth or grooved wall static outer cylinders, is studied experimentally, with the Reynolds number of the inner cylinder reaching up to Rei=2×105, corresponding to the Taylor number up to Ta=5×1010. The grooves are perpendicular to...

[Phys. Rev. E 97, 033110] Published Mon Mar 26, 2018

Barriers to front propagation in laminar, three-dimensional fluid flows

Physical Review E - Mon, 03/26/2018 - 11:00

Author(s): Minh Doan, J. J. Simons, Katherine Lilienthal, Tom Solomon, and Kevin A. Mitchell

This paper presents an experimental study of front propagation in three-dimensional flows, showing evidence of one-way barriers that hinder the motion of the reaction fronts. In order to explain their results, the authors extend the burning-invariant-manifold theory to three dimensions, which enables them to capture the main features of the experimental results.

[Phys. Rev. E 97, 033111] Published Mon Mar 26, 2018

Universality in the nonlinear leveling of capillary films

Physical Review Fluids - Mon, 03/26/2018 - 11:00

Author(s): Zhong Zheng, Marco A. Fontelos, Sangwoo Shin, and Howard A. Stone

A similarity solution of the lubrication equations is presented for the leveling of an interface after a hole in it closes, in agreement with experimental observations.

[Phys. Rev. Fluids 3, 032001(R)] Published Mon Mar 26, 2018

Structural state diagram of concentrated suspensions of jammed soft particles in oscillatory shear flow

Physical Review Fluids - Mon, 03/26/2018 - 11:00

Author(s): Fardin Khabaz, Michel Cloitre, and Roger T. Bonnecaze

We use simulations of large amplitude oscillating shear flow of jamming concentrated suspensions of soft particles to study the developing internal structure, with transitions between glass to FCC and HCP crystals during the oscillation.

[Phys. Rev. Fluids 3, 033301] Published Mon Mar 26, 2018

Wakes behind surface-mounted obstacles: Impact of aspect ratio, incident angle, and surface roughness

Physical Review Fluids - Mon, 03/26/2018 - 11:00

Author(s): Nicolas Tobin and Leonardo P. Chamorro

The dependence of the wake strength behind a windbreak is experimentally investigated as a function of several relevant parameters. A semiempirical model for lateral wake deflection is formulated and found to compare well with experimental data.

[Phys. Rev. Fluids 3, 033801] Published Mon Mar 26, 2018

T-mixer operating with water at different temperatures: Simulation and stability analysis

Physical Review Fluids - Mon, 03/26/2018 - 11:00

Author(s): L. Siconolfi, S. Camarri, and M. V. Salvetti

Flow patterns within a T-mixer are studied numerically when there is a temperature jump between the entering streams. The complex temperature distribution in the outlet channel affects the resulting mixing between the two miscible fluids as well as the bifurcation leading to the engulfment regime.

[Phys. Rev. Fluids 3, 033902] Published Mon Mar 26, 2018

Soft-sphere simulations of a planar shock interaction with a granular bed

Physical Review Fluids - Mon, 03/26/2018 - 11:00

Author(s): Cameron Stewart, S. Balachandar, and Thomas P. McGrath

Discrete element method simulations of a shockwave passing through a bed of particles show the formation of both macroscopic and microscopic particle structures. A particle-wave structure is initiated by a volume-fraction-dependent drag force and intensified by inelastic collisions.

[Phys. Rev. Fluids 3, 034308] Published Mon Mar 26, 2018

Dynamic evolution of Rayleigh-Taylor bubbles from sinusoidal, W-shaped, and random perturbations

Physical Review E - Thu, 03/22/2018 - 10:00

Author(s): Zhi-Rui Zhou, You-Sheng Zhang, and Bao-Lin Tian

Implicit large eddy simulations of two-dimensional Rayleigh-Taylor instability at different density ratios (i.e., Atwood number A=0.05, 0.5, and 0.9) are conducted to investigate the late-time dynamics of bubbles. To produce a flow field full of bounded, semibounded, and chaotic bubbles, three probl...

[Phys. Rev. E 97, 033108] Published Thu Mar 22, 2018

Scale-similar clustering of heavy particles in the inertial range of turbulence

Physical Review E - Thu, 03/22/2018 - 10:00

Author(s): Taketo Ariki, Kyo Yoshida, Keigo Matsuda, and Katsunori Yoshimatsu

Heavy particle clustering in turbulence is discussed from both phenomenological and analytical points of view, where the −4/3 power law of the pair-correlation function is obtained in the inertial range. A closure theory explains the power law in terms of the balance between turbulence mixing and pr...

[Phys. Rev. E 97, 033109] Published Thu Mar 22, 2018

Rayleigh-Bénard turbulence modified by two-way coupled inertial, nonisothermal particles

Physical Review Fluids - Thu, 03/22/2018 - 10:00

Author(s): Hyungwon John Park, Kevin O'Keefe, and David H. Richter

Rayleigh-Bénard convection is simulated to study the effects of inertial, nonisothermal particles on buoyancy-driven turbulent fluid. Distinct particle characteristics, such as gravitational settling and specific heat, are isolated to infer which are dominant in affecting the fluid.

[Phys. Rev. Fluids 3, 034307] Published Thu Mar 22, 2018


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