dynamic_refinement command
Warning
GPU support for this command has not been tested and may not work as expected.Syntax
dynamic_refinement keyword value
Keywords |
Description |
|---|---|
scalar defining the target coarsegraining value.
Parcels with a coarsegraining value larger than this value will be be refined.
|
|
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)
|
scalar defining the ratio of bounding radius of new packing to original
parcel radius, to avoid overlaps.
default:
0.99 |
|
scalar defining the growth rate of child parcel radius per time.
default:
10 |
Examples
dynamic_refinement id dR region reg target_coarsegraining 1.0
dynamic_refinement id dR region reg bounding_sphere_ratio 0.4 &
growth_rate 0.001 target_coarsegraining 1.0
define_group id big
define_group id small
dynamic_refinement id dR1 region reg target_coarsegraining 1.0 particle_group big
dynamic_refinement id dR2 region reg target_coarsegraining 2.0 particle_group small
Description
The command refines parcels that have a coarsegraining value larger than target_coarsegraining.
The created child parcels have the target_coarsegraining value.
Upon entering the region each parent parcel is split into multiple
child parcels. In order to avoid overlaps with walls or other particles, those are arranged
within a bounding sphere that has the size of the original parent parcel
multiplied by the bounding_sphere_ratio.
Subsequently, the child parcels grow by growth_rate until their volume matches
that of the original parent parcel.
Note
Coarsegraining values below 1 result in ill-defined behavior.
Consequently, refinement is only possible until reaching this value.
This restriction needs to be taken into account for setups using this command,
especially when nesting corresponding regions.
Note
In case the ratio of parent and target coarsegraining values cubed is not an
integer, the number of child parcels is rounded up (equal to
ceil((current_cg/target_cg)^3)). Moreover, the coarsegraining value
of the child parcels is adjusted to satisfy the mass conservation.
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!