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Related papers: Dense granular flows: two-particle argument accoun…

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We investigate both numerically and analytically the convective instability of granular materials by two dimensional traffic equations. In the absence of vibrations the traffic equations assume two distinctive classes of fixed bed solutions…

Materials Science · Physics 2009-10-31 Daniel C. Hong , Su Yue

We derive an effective boundary condition for granular flow taking into account the effect of the heterogeneity of the force network on sliding friction dynamics. This yields an intermediate boundary condition which lies in the limit…

Soft Condensed Matter · Physics 2009-11-13 Riccardo Artoni , Andrea Santomaso , Paolo Canu

The flow of a charged-stabilized suspension through a single constricted channel is studied experimentally by tracking the particles individually. Surprisingly, the behavior is found to be qualitatively similar to that of inertial dry…

Fluid Dynamics · Physics 2018-02-14 Alvaro Marin , Henri Lhuissier , Massimiliano Rossi , Christian J. Kaehler

Rheology of a dilute cohesive granular gas is theoretically and numerically studied. The flow curve between the shear viscosity and the shear rate is derived from the inelastic Boltzmann equation for particles having square-well potentials…

Soft Condensed Matter · Physics 2018-04-25 Satoshi Takada , Hisao Hayakawa

Gravitational flow of grains in pipes is frequently encountered in industry. When the grains and pipes are size-constrained, granular flow may result in density waves consisting of alternate high- and low-compactness regions. This paper…

Soft Condensed Matter · Physics 2016-09-01 Erick de Moraes Franklin , Carlos Azael Alvarez Zambrano

To understand the process of pattern formation in a low-density granular flow, we propose a simple particle model. This model considers spherical particles moving over an inclined flat surface based on three forces: gravity as the driving…

Soft Condensed Matter · Physics 2019-04-24 Hirofumi Niiya , Akinori Awazu , Hiraku Nishimori

Discrete element method is conducted to investigate the bidisperse dense granular flow having big and small grains in a two dimensional hopper. A half-circular dynamical force arch is observed above the outlet and Beverloo's law is verified…

Soft Condensed Matter · Physics 2021-06-18 Decai Huang

Granular flows down inclined channels with smooth boundaries are common in nature and in the industry. Nevertheless, the common setup of flat boundaries has comparatively been much less investigated than the bumpy boundaries one, which is…

Soft Condensed Matter · Physics 2012-11-12 Nicolas Brodu , Patrick Richard , Renaud Delannay

Granular systems present surprisingly complicated dynamics. In particular, nonlinear interactions and energy dissipation play important roles in these dynamics. Usually, constant coefficients of restitution are introduced phenomenologically…

Soft Condensed Matter · Physics 2014-08-29 Italo'Ivo Lima Dias Pinto , Alexandre Rosas , Katja Lindenberg

We show that molecular dynamics simulations can furnish useful boundary conditions at a solid surface bounding a two-component fluid. In contrast to some previous reports, convective-diffusive flow is consistent with continuum equations…

Soft Condensed Matter · Physics 2009-11-07 Colin Denniston , Mark O. Robbins

Grain piles embody the complex mechanics and kinematics of disordered granular materials, including solid-like and fluid-like behaviours, complex kinematics, and preparation history-dependent stress variation. It is widely believed that the…

Soft Condensed Matter · Physics 2026-05-29 Aqib Khan , Prabhu R Nott

Particle segregation in dense flowing size-disperse granular mixtures is driven by gravity and shear, but predicting the associated segregation force due to both effects has remained an unresolved challenge. Here, a model of the combined…

Soft Condensed Matter · Physics 2024-11-20 Yifei Duan , Lu Jing , Paul B. Umbanhowar , Julio M. Ottino , Richard M. Lueptow

A two-dimensional dense fluid of frictional grains is shown to exhibit time-chaotic, spatially heterogeneous flow in a range of stress values, $\sigma$, chosen in the unstable region of s-shaped flow curves. Stress controlled simulations…

Soft Condensed Matter · Physics 2016-03-23 Matthias Grob , Annette Zippelius , Claus Heussinger

We probe the diffusive motion of particles in slowly sheared three dimensional granular suspensions. For sufficiently large strains, the particle dynamics exhibits diffusive Gaussian statistics, with the diffusivity proportional to the…

Soft Condensed Matter · Physics 2015-06-11 Elie Wandersman , Joshua A. Dijksman , Martin van Hecke

Predicting particle segregation has remained challenging due to the lack of a general model for the segregation velocity that is applicable across a range of granular flow geometries. Here, a segregation velocity model for dense granular…

Soft Condensed Matter · Physics 2025-10-22 Yifei Duan , Lu Jing , Paul B. Umbanhowar , Julio M. Ottino , Richard M. Lueptow

Preferential concentration of inertial particles in turbulent flow is studied by high resolution direct numerical simulations of two-dimensional turbulence. The formation of network-like regions of high particle density, characterized by a…

Chaotic Dynamics · Physics 2009-11-10 G. Boffetta , F. De Lillo , A. Gamba

The linear stability analysis of an uniform shear flow of granular materials is revisited using several cases of a Navier-Stokes'-level constitutive model in which we incorporate the global equation of states for pressure and thermal…

Soft Condensed Matter · Physics 2008-11-18 Meheboob Alam , Priyanka Shukla , Stefan Luding

We show that a micropolar fluid model successfully describes collisional granular flows on a slope. A micropolar fluid is the fluid with internal structures in which coupling between the spin of each particle and the macroscopic velocity…

Statistical Mechanics · Physics 2009-11-07 Namiko Mitarai , Hisao Hayakawa , Hiizu Nakanishi

We computationally study the frictional properties of sheared granular media subjected to harmonic vibration applied at the boundary. Such vibrations are thought to play an important role in weakening flows, yet the independent effects of…

Soft Condensed Matter · Physics 2023-03-29 Abram H. Clark , H. John Nasrin , Stephanie E. Taylor , Emily E. Brodsky

We investigated the nonlinear effects of gravity-driven fluid flow through a two-dimensional, low-porosity, packed bed of stubby stone grains. We focused on preferential channel formation, tortuosity, spatial distribution of kinetic energy,…