Learning Forum

[martinwagar]

Thank you for your quick response!  

In switching to the k-w model (standard), the issue has been resolved and has very good agreement with the analytical solution (28 kPa) 

# of divisions   k-e pressure drop   k-w pressure drop  

10                     24024                     26496

20                     23594                     26647

30                     22099                     27209

50                     28701                     28580

100                   36663                     29317

200                   41802                     28170

300                   43540                     28196   

 

A few other notes: 

For calculating the mass flow rate, I multiplied by volume flow rate by 999.4 kg/m3, the density of water at my operating temp.  When looking at inlet velocity, I divided the volume flow rate by the cross sectional area of the pipe.

For the mesh, I had absolutely no bias in the radial direction and no bias in the axial direction.  All cells were exactly 1/500th of the axial length and 1/nth of the radial dimension (where n is the number of divisions).

For the axis symmetry, I did use the radius of the pipe.  All of my initial learning in Ansys was via the EDX course offered by Cornell, which didn't have any modules with turbulent pipe flow (only laminar).  Are you referring to the module offered here (https://confluence.cornell.edu/display/SIMULATION/FLUENT+-+Turbulent+Pipe+Flow)?

Lastly, I do plan on using your comments to make the k-e model work.  I'll update here if successful.

Again, I appreciate your quick response!

Ryan