dynamic_coarsening command

Warning

GPU support for this command has not been tested and may not work as expected.

Syntax

dynamic_coarsening  keyword value

Keywords	Description
target_coarsegraining	obligatory; scalar defining the target coarsegraining value. Parcels with a coarsegraining value smaller than this will be coarsened.
region	obligatory; id of the region command the command should be active in
id	string; user-assigned name for the command call (used for referencing this command in the disable_command command)
minimum_radius	scalar defining the radius of a shrinking particle at which it is deleted. default: `0.2 * minimum radius in the simulation`
growth_rate	scalar defining the growth rate of particle radius per time. default: `10`

Examples

dynamic_coarsening id dR region reg target_coarsegraining 8.0
dynamic_coarsening id dR region reg target_coarsegraining 8.0 growth_rate 0.001 minimum_radius 0.001

define_group id big
define_group id small
dynamic_coarsening id dR1 region reg target_coarsegraining 3.0 particle_group big
dynamic_coarsening id dR2 region reg target_coarsegraining 5.0 particle_group small

Description

The command coarsens particles that have a coarsegraining value smaller than target_coarsegraining. Particles are lumped together in a pairwise manner, where one of the particles starts shrinking until it reaches minimum_radius and is then deleted, and the other particle grows. This binary combination of particles is done until the growing particle has reached the target_coarsegraining value.

Restart, fix_modify, output, run start/stop

This command writes no data to binary restart files. None of the fix_modify options are relevant to this fix. No global scalar or vector or per-atom quantities are stored by this fix for access by various output commands. No parameter of this fix can be used with the start/stop keywords of the run command.

Restrictions

This command does not work with non-spherical particles! This command does not work with bonds!