102 lines
2.6 KiB
ReStructuredText
102 lines
2.6 KiB
ReStructuredText
.. index:: pair_style sph/taitwater
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.. index:: pair_style sph/taitwater/gpu
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pair_style sph/taitwater command
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================================
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Accelerator Variants: *sph/taitwater/gpu*
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Syntax
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""""""
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.. code-block:: LAMMPS
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pair_style sph/taitwater
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Examples
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""""""""
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.. code-block:: LAMMPS
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pair_style sph/taitwater
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pair_coeff * * 1000.0 1430.0 1.0 2.4
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Description
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"""""""""""
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The sph/taitwater style computes pressure forces between SPH particles
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according to Tait's equation of state:
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.. math::
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p = B \biggl[\left(\frac{\rho}{\rho_0}\right)^{\gamma} - 1\biggr]
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where :math:`\gamma = 7` and :math:`B = c_0^2 \rho_0 / \gamma`, with
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:math:`\rho_0` being the reference density and :math:`c_0` the reference
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speed of sound.
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This pair style also computes Monaghan's artificial viscosity to
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prevent particles from interpenetrating :ref:`(Monaghan) <Monaghan>`.
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See `this PDF guide <PDF/SPH_LAMMPS_userguide.pdf>`_ to using SPH in
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LAMMPS.
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.. note::
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Please note that the SPH PDF guide file has not been updated for
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many years and thus does not reflect the current *syntax* of the
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SPH package commands. For that please refer to the LAMMPS manual.
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The following coefficients must be defined for each pair of atoms
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types via the :doc:`pair_coeff <pair_coeff>` command as in the examples
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above.
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* :math:`\rho_0` reference density (mass/volume units)
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* :math:`c_0` reference soundspeed (distance/time units)
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* :math:`\nu` artificial viscosity (no units)
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* h kernel function cutoff (distance units)
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----------
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.. include:: accel_styles.rst
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----------
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Mixing, shift, table, tail correction, restart, rRESPA info
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"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
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This style does not support mixing. Thus, coefficients for all
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I,J pairs must be specified explicitly.
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This style does not support the :doc:`pair_modify <pair_modify>`
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shift, table, and tail options.
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This style does not write information to :doc:`binary restart files <restart>`. Thus, you need to re-specify the pair_style and
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pair_coeff commands in an input script that reads a restart file.
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This style can only be used via the *pair* keyword of the :doc:`run_style respa <run_style>` command. It does not support the *inner*,
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*middle*, *outer* keywords.
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Restrictions
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""""""""""""
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This pair style is part of the SPH package. It is only enabled
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if LAMMPS was built with that package. See the :doc:`Build package <Build_package>` page for more info.
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Related commands
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""""""""""""""""
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:doc:`pair_coeff <pair_coeff>`, pair_sph/rhosum
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Default
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"""""""
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none
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----------
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.. _Monaghan:
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**(Monaghan)** Monaghan and Gingold, Journal of Computational Physics,
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52, 374-389 (1983).
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