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

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

:line

fix smd/integrate_ulsph command :h3

[Syntax:]

fix ID group-ID smd/integrate_ulsph keyword :pre

ID, group-ID are documented in "fix"_fix.html command
smd/integrate_ulsph = style name of this fix command
zero or more keyword/value pairs may be appended :ul

keyword = adjust_radius or limit_velocity

adjust_radius values = adjust_radius_factor min_nn max_nn
      adjust_radius_factor = factor which scale the smooth/kernel radius
      min_nn = minimum number of neighbors
      max_nn = maximum number of neighbors
limit_velocity values = max_velocity
      max_velocity = maximum allowed velocity.


[Examples:]

fix 1 all smd/integrate_ulsph adjust_radius 1.02 25 50 :pre
fix 1 all smd/integrate_ulsph limit_velocity 1000 :pre

[Description:]

The fix performs explicit time integration for particles which interact with the updated Lagrangian SPH pair style.
See "this PDF guide"_USER/smd/SMD_LAMMPS_userguide.pdf to using Smooth Mach Dynamics in LAMMPS.

The {adjust_radius} keyword activates dynamic adjustment of the per-particle SPH smoothing kernel radius such that the number of neighbors per particles remains
within the interval {min_nn} to {max_nn}. The parameter {adjust_radius_factor} determines the amount of adjustment per timestep. Typical values are
{adjust_radius_factor}=1.02, {min_nn}=15, and {max_nn}=20.

The {limit_velocity} keyword will control the velocity, scaling the norm of
the velocity vector to max_vel in case it exceeds this velocity limit.

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

Currently, no part of USER-SMD supports restarting nor minimization. This fix has no outputs.

[Restrictions:]

This fix is part of the USER-SMD package.  It is only enabled if
LAMMPS was built with that package. See the "Making LAMMPS"_Section_start.html#start_3
section for more info.

[Related commands:]



[Default:] none
