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add support for determining damping scale factor from atom-style variable

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This commit is contained in:
Axel Kohlmeyer
2022-03-23 10:43:26 -04:00
parent 1fd699d279
commit ae41996967
6 changed files with 199 additions and 46 deletions
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12
doc/src/fix_damping_cundall.rst
View File

@ -19,9 +19,10 @@ Syntax
.. parsed-literal::
keyword = *scale*
*scale* values = type ratio
*scale* values = *type ratio* or *v_name*
type = atom type (1-N)
ratio = factor to scale the damping coefficients by
v_name = reference to atom style variable *name*
Examples
""""""""
@ -30,6 +31,7 @@ Examples
fix 1 all damping/cundall 0.8 0.8
fix 1 all damping/cundall 0.8 0.5 scale 3 2.5
fix a all damping/cundall 0.8 0.5 scale v_radscale
Description
"""""""""""
@ -58,9 +60,13 @@ particle. Damping is applied component-by-component in each direction
{T_d}_k = - \gamma_a \, T_k \, \mathrm{sign}(T_k \omega_k)
The larger the coefficients, the faster the kinetic energy is reduced.
If the optional keyword *scale* is used, :math:`\gamma_l` and :math:`\gamma_a`
can be scaled up or down by the specified factor for atoms of that type.
It can be used multiple times to adjust :math:`\gamma` for several atom types.
can be scaled up or down by the specified factor for atoms. This factor can be
set for different atom types and thus the *scale* keyword used multiple times
followed by the atom type and the associated scale factor. Alternately the
scaling factor can be computed for each atom (e.g. based on its radius) by
using an :doc:`atom-style variable <variable>`.
.. Note::

16
doc/src/fix_viscous_sphere.rst
View File

@ -18,9 +18,10 @@ Syntax
.. parsed-literal::
keyword = *scale*
*scale* values = type ratio
*scale* values = *type ratio* or *v_name*
type = atom type (1-N)
ratio = factor to scale the damping coefficient by
ratio = factor to scale the damping coefficients by
v_name = reference to atom style variable *name*
Examples
""""""""
@ -29,6 +30,7 @@ Examples
fix 1 flow viscous/sphere 0.1
fix 1 damp viscous/sphere 0.5 scale 3 2.5
fix 1 damp viscous/sphere 0.5 scale v_radscale
Description
"""""""""""
@ -43,9 +45,13 @@ technique.
The damping torque :math:`T_i` is given by :math:`T_i = - \gamma \omega_i`.
The larger the coefficient, the faster the rotational kinetic energy is reduced.
If the optional keyword *scale* is used, :math:`\gamma` can be scaled up or
down by the specified factor for atoms of that type. It can be used
multiple times to adjust :math:`\gamma` for several atom types.
If the optional keyword *scale* is used, :math:`\gamma` can be scaled up
or down by the specified factor for atoms. This factor can be set for
different atom types and thus the *scale* keyword used multiple times
followed by the atom type and the associated scale factor. Alternately
the scaling factor can be computed for each atom (e.g. based on its
radius) by using an :doc:`atom-style variable <variable>`.
.. note::