2015-07-30 22:38:28 +08:00
|
|
|
<HTML>
|
|
|
|
<CENTER><A HREF = "http://lammps.sandia.gov">LAMMPS WWW Site</A> - <A HREF = "Manual.html">LAMMPS Documentation</A> - <A HREF = "Section_commands.html#comm">LAMMPS Commands</A>
|
|
|
|
</CENTER>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<HR>
|
|
|
|
|
|
|
|
<H3>pair_style sph/taitwater command
|
|
|
|
</H3>
|
|
|
|
<P><B>Syntax:</B>
|
|
|
|
</P>
|
|
|
|
<PRE>pair_style sph/taitwater
|
|
|
|
</PRE>
|
|
|
|
<P><B>Examples:</B>
|
|
|
|
</P>
|
|
|
|
<PRE>pair_style sph/taitwater
|
|
|
|
pair_coeff * * 1000.0 1430.0 1.0 2.4
|
|
|
|
</PRE>
|
|
|
|
<P><B>Description:</B>
|
|
|
|
</P>
|
|
|
|
<P>The sph/taitwater style computes pressure forces between SPH particles
|
|
|
|
according to Tait's equation of state:
|
|
|
|
</P>
|
|
|
|
<CENTER><IMG SRC = "Eqs/pair_sph_tait.jpg">
|
|
|
|
</CENTER>
|
|
|
|
<P>where gamma = 7 and B = c_0^2 rho_0 / gamma, with rho_0 being the
|
|
|
|
reference density and c_0 the reference speed of sound.
|
|
|
|
</P>
|
|
|
|
<P>This pair style also computes Monaghan's artificial viscosity to
|
|
|
|
prevent particles from interpentrating <A HREF = "#Monaghan">(Monaghan)</A>.
|
|
|
|
</P>
|
|
|
|
<P>See <A HREF = "USER/sph/SPH_LAMMPS_userguide.pdf">this PDF guide</A> to using SPH in
|
|
|
|
LAMMPS.
|
|
|
|
</P>
|
|
|
|
<P>The following coefficients must be defined for each pair of atoms
|
|
|
|
types via the <A HREF = "pair_coeff.html">pair_coeff</A> command as in the examples
|
|
|
|
above.
|
|
|
|
</P>
|
|
|
|
<UL><LI>rho0 reference density (mass/volume units)
|
|
|
|
<LI>c0 reference soundspeed (distance/time units)
|
|
|
|
<LI>nu artificial viscosity (no units)
|
|
|
|
<LI>h kernel function cutoff (distance units)
|
|
|
|
</UL>
|
|
|
|
<HR>
|
|
|
|
|
|
|
|
<P><B>Mixing, shift, table, tail correction, restart, rRESPA info</B>:
|
|
|
|
</P>
|
|
|
|
<P>This style does not support mixing. Thus, coefficients for all
|
|
|
|
I,J pairs must be specified explicitly.
|
|
|
|
</P>
|
|
|
|
<P>This style does not support the <A HREF = "pair_modify.html">pair_modify</A>
|
|
|
|
shift, table, and tail options.
|
|
|
|
</P>
|
|
|
|
<P>This style does not write information to <A HREF = "restart.html">binary restart
|
|
|
|
files</A>. Thus, you need to re-specify the pair_style and
|
|
|
|
pair_coeff commands in an input script that reads a restart file.
|
|
|
|
</P>
|
|
|
|
<P>This style can only be used via the <I>pair</I> keyword of the <A HREF = "run_style.html">run_style
|
|
|
|
respa</A> command. It does not support the <I>inner</I>,
|
|
|
|
<I>middle</I>, <I>outer</I> keywords.
|
|
|
|
</P>
|
|
|
|
<P><B>Restrictions:</B>
|
|
|
|
</P>
|
|
|
|
<P>This pair style is part of the USER-SPH package. It is only enabled
|
|
|
|
if LAMMPS was built with that package. See the <A HREF = "Section_start.html#start_3">Making
|
|
|
|
LAMMPS</A> section for more info.
|
|
|
|
</P>
|
|
|
|
<P><B>Related commands:</B>
|
|
|
|
</P>
|
|
|
|
<P><A HREF = "pair_coeff.html">pair_coeff</A>, pair_sph/rhosum
|
|
|
|
</P>
|
|
|
|
<P><B>Default:</B> none
|
|
|
|
</P>
|
|
|
|
<HR>
|
|
|
|
|
|
|
|
<A NAME = "Monoghan"></A>
|
|
|
|
|
|
|
|
<P><B>(Monaghan)</B> Monaghan and Gingold, Journal of Computational Physics,
|
|
|
|
52, 374-389 (1983).
|
|
|
|
</P>
|
|
|
|
</HTML>
|