14,958 research outputs found
A microscopic theory for discontinuous shear thickening of frictional granular materials
We extend a recent theory for the rheology of frictionless granular materials
[K. Suzuki and H. Hayakawa, Phys. Rev. Lett. 2015, 115, 098001] to the case of
frictional disks in two dimensions. Employing a frictional contact model for
molecular dynamics simulations, we derive difference equations of the shear
stress, the granular temperature, and the spin temperature from the generalized
Green-Kubo formula, where all the terms are given by microscopic expressions.
The numerical solutions of the difference equations not only describe the flow
curve, but also reproduce the hysteresis of shear stress, which can be the
signature of discontinuous shear thickening of frictional disks.Comment: 4 pages, 1 figure, the conference proceedings for Powders & Grains
201
Quantitative test of the time dependent Gintzburg-Landau equation for sheared granular flow in two dimension
We examine the validity of the time-dependent Ginzburg-Landau equation of
granular fluids for a plane shear flow under the Lees-Edwards boundary
condition derived from a weakly nonlinear analysis through the comparison with
the result of discrete element method. We verify quantitative agreements in the
time evolutions of the area fraction and the velocity fields, and also find
qualitative agreement in the granular temperature.Comment: 10 pages, 4 figures. This paper is one of contributed papers to the
proceedings of IUTAM symposium on "MOBILE PARTICULATE SYSTEMS: Kinematics,
Rheology and Complex Phenomena" held at Bangalore in January 23-27, 201
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