Hey all,
I had thought that too but line 2061 of lbgpu has an if which just skips the kernel call:
if (para.fluct){thermalize_modes(mode, index, &rng);}
One other thought about making movies is if one just wants a neat picture one can do the following:
for {set i 0} {$i<$N} {incr i} {
part $i fix 1 1 1 mu_E $vx $vy $vz
}
where you have to give the velocity you expect $vx $vy $vz for particle $i. The particles themselves don't move but you can still get a reasonable looking flow field, assuming you have some idea what values to use for vx vy and vz.
Owen