Onset of Patterns in Continuum and Molecular Dynamics Simulations of an Oscillated Granular Layer
Abstract
We study the onset of patterns in vertically oscillated layers of frictionless dissipative particles. Using both numerical solutions of continuum equations to Navier-Stokes order and molecular dynamics (MD) simulations, we find that standing waves form stripe patterns above a critical acceleration of the cell. Changing the oscillation frequency of the cell changes the resulting pattern wavelength; wavelengths from both simulations reproduce previous experimental results. The critical acceleration for ordered standing waves is approximately 10% higher in MD simulations than in the continuum simulations, and the amplitude of the waves differs between the models, consistent with the presence of noise in the system. The noise strength is found by fit to Swift-Hohenberg theory and is compared to the noise found in experiments with oscillated granular layers and to the thermal noise found in experiments on Rayleigh-Bénard convection.
- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2004
- Bibcode:
- 2004APS..DFD.FH003S