66 lines
1.7 KiB
ReStructuredText
66 lines
1.7 KiB
ReStructuredText
.. index:: compute smd/tlsph/dt
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compute smd/tlsph/dt command
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============================
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Syntax
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""""""
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.. code-block:: LAMMPS
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compute ID group-ID smd/tlsph/dt
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* ID, group-ID are documented in :doc:`compute <compute>` command
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* smd/tlsph/dt = style name of this compute command
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Examples
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""""""""
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.. code-block:: LAMMPS
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compute 1 all smd/tlsph/dt
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Description
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"""""""""""
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Define a computation that outputs the CFL-stable time increment per
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particle. This time increment is essentially given by the speed of
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sound, divided by the SPH smoothing length. Because both the speed of
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sound and the smoothing length typically change during the course of a
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simulation, the stable time increment needs to be re-computed every
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time step. This calculation is performed automatically in the
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relevant SPH pair styles and this compute only serves to make the
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stable time increment accessible for output purposes.
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See `this PDF guide <PDF/MACHDYN_LAMMPS_userguide.pdf>`_ to using Smooth
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Mach Dynamics in LAMMPS.
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Output info
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"""""""""""
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This compute calculates a per-particle vector, which can be accessed
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by any command that uses per-particle values from a compute as input.
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See the :doc:`Howto output <Howto_output>` page for an overview of
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LAMMPS output options.
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The per-particle values will be given in :doc:`units <units>` of time.
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Restrictions
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""""""""""""
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This compute is part of the MACHDYN package. It is only enabled if
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LAMMPS was built with that package. See the :doc:`Build package <Build_package>` page for more info.
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This compute can only be used for particles interacting with the
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Total-Lagrangian SPH pair style.
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Related commands
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""""""""""""""""
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:doc:`smd/adjust/dt <fix_smd_adjust_dt>`
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Default
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"""""""
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none
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