fixed value problem
 

Hi all,
I need some help. I am attempting to use the fixed variables to simulate flow at the interior. The matter is kind of complex. Anyway, to keep it short, the zone where I want to specify my fixed values is a cylindrical region. I wrote a UDF that accounts for the x and y and the angle formed such that the velocity from the fan is always in the radial (normal direction).

However, when I start my simulation, I have problems with convergence. I plotted the flow profile and this is what I got:



The green part is the zone where the fixed values are specified. The empty region is a wall tube. I should be getting outward flow aong the green part but instead, I only got flow at the center and circulation occurs. Note that the diameter of the zone is greater than the wall tube.

Does anyone know why this is happening?


Thanks a lot.


Sincerely,
EH