[bf3g10]

I have modelled a cylindrical pipe on the order of microns to simulate a microfluidic, incompressible, isothermal flow as you would when you're first starting out with Fluent.

Naturally, a sensible way to analyse the velocity profile is via the Hagen-Poiseuille equation and I determined that with an inlet pressure of 1Pa and a pipe radius of 100 microns and length of 2mm, that the maximum velocity in the centre of the pipe should be roughly 3x10^-4 m/s.

After simulation, the maximum velocity appears to be 2.534x10^-2 m/s; which is roughly a 100 times faster!

I've double checked my boundary conditions and fluid properties (I should mention that it is simply water) and they appear to be okay. Inlet pressure set at 1Pa; outlet pressure at 0Pa; no-slip at walls; dynamic viscosity of water at 10^-3 Pas and density of 1000kg/m^3.

I've also tried mucking about with the solution methods, in particular between standard, linear and second order settings for pressure and momentum and they all appear to be giving the same results.
Presumably I must be missing something obvious. Any suggestions would be much appreciated.