Minimum channel size
What is the minimum channel size that can be modeled accurately with FLUENT?
Following a discussion with experimentalists who also use Fluent we've got a (current) minimum channel size for accurate solutions.
According to the contimuity theory it is possible for this approach using the Navier-Stokes equations to function at approximately 1 micron. At this dimension the code produces numerically correct results, however these don't agree with the experimental data. It has been found that accurate comparrisson with experimental data stops at approximately 10micron.
Reasons for this are due to Fluent not accounting for Van der Waals forces, surface roughness & wetting effects, molecular dipole moments etc. It should also be noted that there are errors associated with experimental data at this level.
Note this is for a single phase model, liquid phase.
Minimum dimensions for the gas phase are determined by the limitations of the Continuity approach used in Fluent. This can be judged using the Knudsen Number, a ratio of the channel size and molecular mean free path.