Article
Mechanics
Guanghui Yang, Sheng Zhang, Ping Lin
Summary: An inclined granular flow on an ordered bottom exhibits complex behaviors, including transitions between ordered and disordered states. The ordered flow is unstable and deviates from the Newtonian velocity distribution. The disordered flow maintains a Bagnold-type flow above the hot basal layer.
Article
Physics, Multidisciplinary
Ryosuke Yano
Summary: This study investigates the recollisional effects of granular particles on the spherically symmetric moments and fluctuation-dissipation relation when driven by a Gaussian thermostat. The results show that the recollisional effects on these moments and coefficients increase with a decrease in the restitution coefficient.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Mechanics
Ruben Gomez Gonzalez, Vicente Garzo
Summary: The time evolution of a homogeneous bidisperse granular suspension is studied under the Enskog kinetic equation, showing the system reaches a universal unsteady hydrodynamic regime and analyzing the Mpemba-like effect for inelastic collisions. The comparison with DSMC results confirms the applicability of hydrodynamics in granular suspensions.
Article
Materials Science, Multidisciplinary
Manali Vivek, Jacek Goniakowski, Andres Santander-Syro, Marc Gabay
Summary: Angle-resolved photoemission spectroscopy experiments have revealed the presence of a nanometer-thin two-dimensional electron system (2DES) on the (001)-oriented surface of CaTiO3, despite being a band insulator. Our ab initio study indicates that oxygen defects drive the metallicity, while tiltings and rotations of the oxygen octahedra significantly influence the electronic structure and response to external strain deformations of the 2DES. The conduction subbands near the center of the Brillouin zone exhibit a mixed t2g-eg orbital character. TiO2 surface divacancy configurations agree well with experimental spectra.
Article
Engineering, Geological
Chen-Xi Tong, Ming-Yue Zhai, Hai-Chao Li, Sheng Zhang, Daichao Sheng
Summary: This paper summarizes the latest advances in studying the effects of soil particle breakage on soil mechanics properties and relevant constitutive models. By quantifying particle size distribution and the evolution of particle breakage, a new critical state model treating PSD as a variable is proposed. The model is validated against experimental data and compared with other constitutive models, showing satisfactory performance.
Article
Environmental Sciences
Fu-Jie Zhu, Wan-Li Ma, Zi-Feng Zhang, Pu-Fei Yang, Peng-Tuan Hu, Li-Yan Liu, Wei-Wei Song
Summary: Gas/particle (G/P) partitioning is an important factor for the environmental fate of semi-volatile organic compounds (SVOCs). This study established empirical equations based on ambient temperature to predict the G/P partitioning quotient (Kp) of polycyclic aromatic hydrocarbons (PAHs) in a wide temperature range. The empirical equations showed good performance in predicting Kp based on ambient temperature. However, deviations from previous G/P partitioning models were observed, suggesting the need to consider additional influencing factors. Further research should be conducted to study the mechanism of PAHs G/P partitioning and improve the partitioning models.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Engineering, Environmental
Jinyi Tian, Yuqing Gao, Xiaoyun Ye, Fei Huang, Yuwei Zhao, Tong Zhang, Wei Zhao, Xiurong Chen, Hualin Wang, Shibo Kuang
Summary: A gravity-driven hydrocyclone was proposed for the separation and activation of granular sludge without the need for an intake pump. CFD simulations showed that the inclination angle affected fluid flow, particle motion, and separation performance, but had little influence on particle rotation and translation. The new hydrocyclone achieved efficient separation and the split ratio increased with the inclination angle.
JOURNAL OF WATER PROCESS ENGINEERING
(2023)
Article
Engineering, Mechanical
Chao-Fa Zhao, Niels P. Kruyt
Summary: The study compares the rotational behavior of granular materials at the particle level to the continuum level, finding that the average particle rotation closely matches the continuum rotation. X-ray tomography of granular soil under triaxial compression further supports this observation. The presence of contact couples is found to have a significant effect on stress ratios and volumetric strain in simulations. Stress tensors remain symmetric even with the inclusion of contact couples.
JOURNAL OF ENGINEERING MECHANICS
(2021)
Article
Mathematics, Applied
Nityananda Roy, Karunia Putra Wijaya, Thomas Goetz, S. Sundar
Summary: The paper aims to model and study the behavior of ellipsoidal microplastic particles in a 3D lid-driven cavity with an Eulerian equation for hydrodynamics and a Lagrangian system for particle dynamics. The analysis focuses on laminar flow, small particle Reynolds number, and extreme particle aspect ratios using Singular Perturbation Theory. Results show that sedimentation is highly dependent on initial particle position, aspect ratio, and size, with neutrally buoyant particles preferring to deposit on cavity base or vorticity-dominating regions. Buoyant particles with aspect ratios between 1/20 and 20 spin faster than tumble, and even faster with smaller aspect ratios.
APPLIED MATHEMATICS AND COMPUTATION
(2022)
Article
Water Resources
Mojtaba Jandaghian, Ahmad Shakibaeinia
Summary: In this study, a new multi-resolution mesh-free particle method was developed to investigate the dynamics of rapid fluid-driven granular erosion. The proposed method was validated through numerical benchmark cases and used to study fluid-driven granular flow. The results showed that the density ratio between the water bed and sediment significantly affected the mechanical behavior of the system, and the multi-resolution model accurately estimated the global sediment dynamics.
ADVANCES IN WATER RESOURCES
(2023)
Article
Physics, Multidisciplinary
Nikolay Stepanov, Mikhail Skvortsov
Summary: We study the stochastic dynamics of an inverted pendulum subject to a random force in the horizontal direction and develop a statistical description based on the supersymmetric formalism. We obtain an exact solution for the joint distribution function of the pendulum's angle and velocity in the limit of strong driving.
Article
Engineering, Environmental
Shuang Jiao, Chengshun Xu, Shuang Xu, Jialin Xu
Summary: The discrete element method (DEM) can be used to study the breakage of granular materials from a microscopic perspective. Through numerical simulations, the influencing factors and microscopic responses of breakage are investigated, as well as the critical state of crushed specimens. The results show that the shearing dilatancy characteristics are governed by the stress level and that the content of fine particles affects the amount of breakage. Particle breakage mainly occurs at the early stage of shear at low confining pressure, while it accompanies the whole shear process at high confining pressure.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2023)
Article
Multidisciplinary Sciences
T. Doppner, M. Bethkenhagen, D. Kraus, P. Neumayer, D. A. Chapman, B. Bachmann, R. A. Baggott, M. P. Bohme, L. Divol, R. W. Falcone, L. B. Fletcher, O. L. Landen, M. J. MacDonald, A. M. Saunders, M. Schorner, P. A. Sterne, J. Vorberger, B. B. L. Witte, A. Yi, R. Redmer, S. H. Glenzer, D. O. Gericke
Summary: This article reports on an experiment that creates and diagnoses matter at pressures exceeding three gigabars. The experiment shows the presence of quantum-degenerate electrons and strongly reduced elastic scattering under extreme conditions.
Article
Physics, Multidisciplinary
Tian Bao-Xian, Wang Zhao, Hu Feng-Ming, Gao Zhi-Xing, Ban Xiao-Na, Li Jing
Summary: The study focused on the equation of state (EOS) of CH material under high pressure and the shock dynamic behaviors of different CH targets, revealing that the reflected rarefaction waves from the Al-coated CH target can delay the formation of shock waves and increase the pressure. Experimental results showed that the pressure in CH and Al-coated CH planar targets was significantly lower than in the flyer-impact target.
ACTA PHYSICA SINICA
(2021)
Article
Physics, Multidisciplinary
Alexander Poshakinskiy, Janet Zhong, Alexander N. Poddubny
Summary: The study theoretically explores quantum states of a pair of photons interacting with a periodic array of two-level atoms in a waveguide, revealing irregular wave functions and the breakdown of Bethe ansatz, leading to quantum chaos. The long range waveguide-mediated coupling between atoms is identified as the key factor for chaos and nonintegrability in this system, providing new insights into the interplay between order, chaos, and localization in many-body quantum systems.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
M. Noirhomme, A. Cazaubiel, E. Falcon, D. Fischer, Y. Garrabos, C. Lecoutre-Chabot, S. Mawet, E. Opsomer, F. Palencia, S. Pillitteri, N. Vandewalle
Summary: The study experimentally investigates the behavior of few large tracer particles in a quasi-2D granular gas made of small beads in a low-gravity environment. It is found that translational energy equipartition is reached at the onset of the gas-liquid granular transition, accompanied by the emergence of local clusters. The dynamics of the tracer particles can be used as a simple and accurate tool to detect this transition, with a proposed model accurately describing the formation of local heterogeneities.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
Dmitry Puzyrev, David Fischer, Kirsten Harth, Torsten Trittel, Raul Cruz Hidalgo, Eric Falcon, Martial Noirhomme, Eric Opsomer, Nicolas Vandewalle, Yves Garrabos, Carole Lecoutre, Fabien Palencia, Ralf Stannarius
Summary: Studying the dynamics of granular multiparticle ensembles requires optical analysis methods. Numerical simulations similar to experiments can be used to validate the reliability of analysis methods. This approach not only confirms the accuracy of simulations, but also tests the applicability of visual analysis.
SCIENTIFIC REPORTS
(2021)
Review
Mechanics
Eric Falcon, Nicolas Mordant
Summary: In the past decade, there has been a significant increase in wave turbulence studies, particularly in the field of water waves. The theoretical modeling of ocean waves, which has driven the development of weak turbulence theory, has been found to be too idealized to capture experimental observations. Laboratory observations have revealed that the waves studied are actually gravity-capillary waves, as opposed to ocean waves. This richer physics has led to various physical effects beyond the theoretical framework, especially in the gravity-capillary crossover region.
ANNUAL REVIEW OF FLUID MECHANICS
(2022)
Article
Physics, Multidisciplinary
Guillaume Ricard, Eric Falcon
Summary: This study reports the first observation of unidirectional capillary-wave turbulence on the surface of a fluid in a canal, and reveals that five-wave interactions are likely responsible for generating such turbulence at small scales. The wave spectrum is found to be in line with dimensional analysis predictions, and the main assumptions of weak turbulence theory are experimentally verified. Quasi-1D wave turbulence may have implications for other fields of wave turbulence.
Article
Physics, Fluids & Plasmas
Alexey Tikan, Felicien Bonnefoy, Giacomo Roberti, Gennady El, Alexander Tovbis, Guillaume Ducrozet, Annette Cazaubiel, Gaurav Prabhudesai, Guillaume Michel, Francois Copie, Eric Falcon, Stephane Randoux, Pierre Suret
Summary: The Peregrine soliton (PS) is a prototype nonlinear structure that captures the properties of rogue waves. Recent research has shown that the PS can emerge independently of its solitonic content from partially radiative or solitonless initial data. In this study, the researchers controlled the occurrence of the PS in space-time by adjusting the initial chirp. The proposed method of nonlinear spectral engineering was found to be robust to higher-order nonlinear effects.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Physics, Multidisciplinary
Filip Novkoski, Chi-Tuong Pham, Eric Falcon
Summary: We report on the experimental observation of solitons propagating along a torus of fluid. We show that such a periodic system leads to significant differences compared to the classical plane geometry, including the observation of subsonic elevation solitons and a nonlinear dependence of soliton velocity on its amplitude. By imposing periodic boundary conditions onto the KdV equation, we recover these observations. Our work reveals the importance of periodicity for studying solitons and validates a nonlinear spectral analysis method in this periodic geometry.
Article
Mechanics
Guillaume Michel, Felicien Bonnefoy, Guillaume Ducrozet, Eric Falcon
Summary: This study investigates the statistics of rogue waves occurring in the inverse cascade of surface gravity wave turbulence. It reveals that in statistically homogeneous, stationary and isotropic wave fields, low-frequency waves are generated by nonlinear interactions instead of direct forcing. The analysis of thousands of rogue waves shows that certain properties crucially depend on four-wave resonant interactions, with larger crests being more likely than predicted by second-order models.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Physics, Multidisciplinary
Jean-Baptiste Gorce, Eric Falcon
Summary: We experimentally investigate 3D hydrodynamic turbulence at scales larger than the forcing scale and manage to separate the forcing scale from the container size. Our results show that the large-scale dynamics are in statistical equilibrium and can be described using an effective temperature, though not isolated from the turbulent Kolmogorov cascade.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Michael Berhanu, Simon Merminod, Gustavo Castillo, Eric Falcon
Summary: This study investigates fluid-like and crystal-like states in a driven granular material. The findings reveal collective excitations characterized by dispersion relations, analogous to phonons in condensed matter, propagate in the system. When the magnetic coupling is weak, the waves are longitudinal, while both longitudinal and transverse waves propagate when the coupling is stronger, similar to solid-like phases.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2022)
Article
Multidisciplinary Sciences
Alexey Tikan, Felicien Bonnefoy, Guillaume Ducrozet, Gaurav Prabhudesai, Guillaume Michel, Annette Cazaubiel, Eric Falcon, Francois Copie, Stephane Randoux, Pierre Suret
Summary: In this study, we numerically and experimentally investigate the concept of nonlinear dispersion relation (NDR) in the context of partially coherent waves propagating in a one-dimensional water tank. The NDR of the slowly varying envelope of the deep-water waves is accurately measured using a limited number of wave gauges, providing precise characterization of frequency shift and NDR broadening, as well as revealing the presence of solitons. Our analysis shows that the shape and broadening of the NDR can indicate deviation from integrable turbulence induced by high order effects in experiments. We also compare our experimental observations with numerical simulations.
SCIENTIFIC REPORTS
(2022)
Article
Physics, Fluids & Plasmas
Guillaume Ricard, Eric Falcon
Summary: We experimentally observe a transition from dispersive wave turbulence to a nondispersive regime involving shock waves on a fluid surface. By tuning the dispersivity of the system using a magnetic fluid in a canal subjected to an external horizontal magnetic field, we observe gravity-capillary wave turbulence at low magnetic field and random steep coherent structures which are shock waves at high enough field. These shock waves generate singularities in the second-order difference of the surface elevation and exhibit an omega-4 frequency power spectrum.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Physics, Fluids & Plasmas
Jules Fillette, Stephan Fauve, Eric Falcon
Summary: We report on an experimental study of axisymmetric gravity-capillary standing waves generated by a vertically vibrating ring partially immersed into a fluid. Different regimes of standing waves are observed at the basin center depending on the forcing parameters: linear, nonlinear, and ejection regimes. The experimental spatial profile of standing waves breaks the up-down symmetry for stronger forcing and is well described by a third-order nonlinear theory. Furthermore, the maximum height of the wave crest at the basin center increases linearly with its wavelength as the forcing is further increased, due to the saturation of its steepness, which is well captured by a proposed model.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Physics, Fluids & Plasmas
Filip Novkoski, Chi-Tuong Pham, Eric Falcon
Summary: We observe the nonlinear three-wave resonant interactions between the gravity-capillary and sloshing modes of hydrodynamic waves. A triadic resonance instability is observed, with exponential growth and phase locking. The efficiency of the interaction is highest when the gravity-capillary phase velocity matches the group velocity of the sloshing mode. Additional waves are generated through a cascade of three-wave interactions for stronger forcing, filling the wave spectrum. This mechanism may have relevance in systems involving multiple propagation modes.
Article
Physics, Fluids & Plasmas
Jean-Baptiste Gorce, Eric Falcon
Summary: In this study, we investigate the dynamics of magnets in a fluid under the influence of a vertical oscillating magnetic field. Unlike previous studies on granular gas, where energy is injected by vibrating the boundaries, our system does not show cluster formation, orientational correlation, and equipartition of energy. The linear velocity distributions of the magnets exhibit stretched exponentials, similar to boundary-forced dry granular gas systems, but the exponent is independent of the number of magnets. The conversion rate of angular momentum into linear momentum during collisions plays a crucial role in controlling the dynamics of this homogenously forced granular gas. We also compare our findings with ideal gas and nonequilibrium boundary-forced dissipative granular gas systems.
Article
Physics, Fluids & Plasmas
Evgeny Kochurin, Guillaume Ricard, Nikolay Zubarev, Eric Falcon
Summary: We present a three-dimensional direct numerical simulation of wave turbulence on the free surface of a magnetic fluid under an external horizontal magnetic field. We observe a transition from capillary-wave turbulence to anisotropic magneto-capillary wave turbulence with increasing magnetic field strength. At high enough magnetic field, the wave turbulence becomes highly anisotropic, cascading predominantly perpendicular to the field direction. This finding is in good agreement with the prediction of a phenomenological model and with anisotropic Alfven wave turbulence. Although surface waves on a magnetic fluid differ from Alfven waves in plasma, strong analogies exist in terms of wave spectrum scalings and magnetic-field dependent dispersionless wave velocities.
