"LIGGGHTS WWW Site"_liws - "LAMMPS WWW Site"_lws - "LIGGGHTS Documentation"_ld - "LIGGGHTS Commands"_lc :c

:link(liws,http://www.cfdem.com)
:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Section_commands.html#comm)

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fix sph/density/summation command :h3

[Syntax:]

fix ID group-ID sph/density/summation :pre

ID, group-ID are documented in "fix"_fix.html command
sph/density/summation = style name of this fix command :ul

[Examples:]

fix density all sph/density/summation :pre

[LIGGGHTS vs. LAMMPS Info:]

This command is not available in LAMMPS.

[Description:]

Calculates the density field with the classic SPH-summation approach. The governing equation is given by:

:c,image(Eqs/fix_sph_density_summation.jpg)

rho<sub>a</sub> is the density of particle a, m is the mass and W<sub>ab</sub> denotes the interpolating kernel for the particle-particle distance r<sub>a</sub> - r<sub>b</sub>. The summation is over all particles b other than particle a.

NOTE: In the current version boundary or image particles are not implemented. Therefore, the density calculation in the vicinity to a wall will be wrong.

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[Restart, fix_modify, output, run start/stop, minimize info:]

No information about this fix is written to "binary restart files"_restart.html.

None of the "fix_modify"_fix_modify.html 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"_Section_howto.html#4_15.

No parameter of this fix can be used with the {start/stop} keywords of the "run"_run.html command.

This fix is not invoked during "energy minimization"_minimize.html.

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[Restrictions:]

There can be only one fix sph/density/... (except "fix sph/density/corr"_fix_sph_density_corr.html)

[Related commands:]

"pair_style sph/artVisc/tensCorr"_pair_sph_artvisc_tenscorr.html, "fix sph/pressure"_fix_sph_pressure.html, "fix sph/density/continuity"_fix_sph_density_continuity.html

[Default:] none

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:link(LiuLiu2003)
[(Liu and Liu, 2003)] "Smoothed Particle Hydrodynamics: A Meshfree Particle Method", G. R. Liu and M. B. Liu, World Scientific, p. 449 (2003).

:link(Monaghan1992)
[(Monaghan, 1992)] "Smoothed Particle Hydrodynamics", J. J. Monaghan, Annu. Rev. Astron. Astrophys., 30, p. 543-574 (1992).

