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.
</P>
<P><B>Examples:</B>
</P>
<PRE>fix 1 all smd/integrate_ulsph adjust_radius 1.02 25 50
</PRE>
<PRE>fix 1 all smd/integrate_ulsph limit_velocity 1000
</PRE>
<P><B>Description:</B>
</P>
<P>The fix performs explicit time integration for particles which interact with the updated Lagrangian SPH pair style.
See <AHREF ="USER/smd/SMD_LAMMPS_userguide.pdf">this PDF guide</A> to using Smooth Mach Dynamics in LAMMPS.
</P>
<P>The <I>adjust_radius</I> keyword activates dynamic adjustment of the per-particle SPH smoothing kernel radius such that the number of neighbors per particles remains
within the interval <I>min_nn</I> to <I>max_nn</I>. The parameter <I>adjust_radius_factor</I> determines the amount of adjustment per timestep. Typical values are
<I>adjust_radius_factor</I>=1.02, <I>min_nn</I>=15, and <I>max_nn</I>=20.
</P>
<P>The <I>limit_velocity</I> keyword will control the velocity, scaling the norm of
the velocity vector to max_vel in case it exceeds this velocity limit.
</P>
<P><B>Restart, fix_modify, output, run start/stop, minimize info:</B>
</P>
<P>Currently, no part of USER-SMD supports restarting nor minimization. This fix has no outputs.
</P>
<P><B>Restrictions:</B>
</P>
<P>This fix is part of the USER-SMD package. It is only enabled if
LAMMPS was built with that package. See the <AHREF ="Section_start.html#start_3">Making LAMMPS</A>