Latest papers in fluid mechanics
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
Author(s): G. Dong, B. Liao, Y. Ma, and M. Perlin
A series of laboratory experiments were performed to study the Peregrine Breather evolution in a wave flume of finite depth and deep water. The experimental results are compared with computations based on both the nonlinear Schrödinger equation and the Dysthe equation, both with a dissipation term.
[Phys. Rev. Fluids 3, 064801] Published Mon Jun 04, 2018
Author(s): Quoc Vo and Tuan Tran
Droplets on a surface immersed in oil are made to spread and retract by switching on and off a potential difference between the droplets and the surface. The authors find that the contact line friction depends on the viscosities of the droplet and the surrounding oil and that it does not depend significantly on the driving force or the direction of motion.
[Phys. Rev. E 97, 063101] Published Fri Jun 01, 2018
Author(s): Itzhak Fouxon, Lukas Schmidt, Peter Ditlevsen, Maarten van Reeuwijk, and Markus Holzner
We investigate how an initially uniform distribution of small inertial particles evolves due to transport by turbulent channel flow. Concentration fluctuations grow as particles approach a multifractal attractor with strong dependence on the distance to the wall which can be faster than exponential.
[Phys. Rev. Fluids 3, 064301] Published Fri Jun 01, 2018
Author(s): V. Langlois, V. H. Trinh, C. Lusso, C. Perrot, X. Chateau, Y. Khidas, and O. Pitois
In this paper, we study how the permeability of solid foam is modified by the presence of membranes that close partially or totally the cell windows connecting neighboring pores. The finite element method (FEM) simulations computing the Stokes problem are performed at both pore and macroscopic scale...
[Phys. Rev. E 97, 053111] Published Thu May 31, 2018
Author(s): D. Veysset, U. Gutiérrez-Hernández, L. Dresselhaus-Cooper, F. De Colle, S. Kooi, K. A. Nelson, P. A. Quinto-Su, and T. Pezeril
In this study a single laser pulse spatially shaped into a ring is focused into a thin water layer, creating an annular cavitation bubble and cylindrical shock waves: an outer shock that diverges away from the excitation laser ring and an inner shock that focuses towards the center. A few nanosecond...
[Phys. Rev. E 97, 053112] Published Thu May 31, 2018
Author(s): Meurig T. Gallagher and David J. Smith
We develop a tool for simulating three-dimensional locomotion in Stokes flow with highly resolved flow and swimming trajectories for multiple swimmers in the presence of surfaces. Key features include modularity, scalability, ease of implementation, and no need for mesh generation.
[Phys. Rev. Fluids 3, 053101] Published Thu May 31, 2018
Author(s): Nazmi Burak Budanur and Björn Hof
Numerical experiments demonstrate that the laminar-turbulent boundary in pipe flow exhibits qualitatively different regions whose dynamics resemble that of the nearby unstable invariant solutions. In addition, various different state space paths to turbulence from this boundary are illustrated.
[Phys. Rev. Fluids 3, 054401] Published Wed May 30, 2018
Author(s): Haosen H. A. Xu and X. I. A. Yang
Fluid motions in the inertial range of isotropic turbulence are fractal, with their space-filling capacity slightly below regular three-dimensional objects, which is a consequence of the energy cascade. Besides the energy cascade, the other often encountered cascading process is the momentum cascade...
[Phys. Rev. E 97, 053110] Published Tue May 29, 2018
Author(s): A. D. Kiverin and I. S. Yakovenko
The gas-dynamical mechanism of ignition kernels formation in shock tubes is formulated on the basis of numerical analysis of the flow pattern developed behind the shock wave propagating in the rectangular tube filled with a reactive gaseous mixture.
[Phys. Rev. Fluids 3, 053201] Published Tue May 29, 2018
Hexagonal convection patterns and their evolutionary scenarios in electroconvection induced by a strong unipolar injection
Author(s): Kang Luo, Jian Wu, Hong-Liang Yi, Lin-Hua Liu, and He-Ping Tan
Various flow patterns and their evolutionary scenarios in three-dimensional electroconvection are numerically investigated. Specifically, a careful comparison of the hexagonal pattern is made to the previous semianalytical stability analysis results.
[Phys. Rev. Fluids 3, 053702] Published Tue May 29, 2018
Author(s): Rikhi Bose, Tamer A. Zaki, and Paul A. Durbin
The role of instability waves (IW) in free-stream turbulence (FST) induced boundary-layer transition in an adverse pressure gradient is studied with direct simulations. IW are found relevant even at moderate FST intensity of 2%. The effect of FST spectrum and intensity on transition are explored.
[Phys. Rev. Fluids 3, 053904] Published Tue May 29, 2018
Author(s): Kazuhiko Suga, Yuki Mori, Rintaro Moritani, and Masayuki Kaneda
Molecular dynamics simulations are carried out to investigate the geometry effects of diatomic molecules on liquid flows in carbon nanotubes (CNTs). Oxygen molecules are considered as the fluid inside armchair (n,n) (n=6–20) CNTs. The simulated fluid temperature and bulk pressure for the liquid stat...
[Phys. Rev. E 97, 053109] Published Fri May 25, 2018
Author(s): Izumi Saito, Toshiyuki Gotoh, and Takeshi Watanabe
Collision-coalescence growth of noninertial particles in three-dimensional homogeneous isotropic turbulence is studied. Smoluchowski's coagulation equation describes the evolution of the size distribution of particles in this system. By applying a methodology based on turbulence theory, the equation...
[Phys. Rev. E 97, 053108] Published Thu May 24, 2018
Scalewise invariant analysis of the anisotropic Reynolds stress tensor for atmospheric surface layer and canopy sublayer turbulent flows
Author(s): Peter Brugger, Gabriel G. Katul, Frederik De Roo, Konstantin Kröniger, Eyal Rotenberg, Shani Rohatyn, and Matthias Mauder
The return-to-isotropy of turbulence across scales is studied for different thermal stratification and surface roughness regimes from measurements in the atmospheric boundary layer and it is compared with predictions of a homogenous model.
[Phys. Rev. Fluids 3, 054608] Published Thu May 24, 2018
Author(s): P. McGavin and D. I. Pontin
The evolving topology of vortex lines during reconnection of vortex tubes is addressed. New features of the reconnection process are revealed, such as the generation of many small flux rings, and of vorticity null points. Methods to measure changes in flux connectivity are discussed.
[Phys. Rev. Fluids 3, 054701] Published Wed May 23, 2018
Three-dimensional instabilities of natural convection between two differentially heated vertical plates: Linear and nonlinear complementary approaches
Author(s): Zhenlan Gao, Berengere Podvin, Anne Sergent, Shihe Xin, and Jalel Chergui
The transition to the chaos of the air flow between two vertical plates maintained at different temperatures is studied in the Boussinesq approximation. After the first bifurcation at critical Rayleigh number Rac, the flow consists of two-dimensional (2D) corotating rolls. The stability of the 2D ro...
[Phys. Rev. E 97, 053107] Published Tue May 22, 2018
Author(s): Mirko Gallo, Francesco Magaletti, and Carlo Massimo Casciola
A continuum model embedding thermal fluctuations, capillarity, and hydrodynamic effects is proposed to investigate bubble cavitation. The simulations, validated against molecular dynamics, access multibubble nucleation statistics and long-time dynamics in unprecedentedly large domains.
[Phys. Rev. Fluids 3, 053604] Published Tue May 22, 2018
Author(s): Daniel Foti, Xiaolei Yang, Filippo Campagnolo, David Maniaci, and Fotis Sotiropoulos
We present wind tunnel and numerical experiments of the flow behind a model wind turbine in optimal and sub-optimal regimes. Spatio-temporal filtering and dynamic mode decomposition reveal that the onset and amplitude of wake meandering are affected by both the operating regime and the nacelle.
[Phys. Rev. Fluids 3, 054607] Published Tue May 22, 2018
Author(s): Babak Rabbanipour Esfahani, Silvia C. Hirata, Stefano Berti, and Enrico Calzavarini
The evolution of heat flux through an initially solid pure substance that is heated from below and that undergoes both phase-change and natural convection is studied numerically and contrasted with the dynamics of the Rayleigh-Bénard system in laminar and turbulent regimes.
[Phys. Rev. Fluids 3, 053501] Published Mon May 21, 2018