Fluent 5.2, UDF and Pressure BC's

Alfonso Ferrandez

Dear all,

I've been working on a UDF for a loooong time now and there's something that's been baffling me ever since I started with it. Here's the details:

1) 2D Unsteady Incompressible

2) Pressure Inlet BC's (set with UDF and/or CONSTANT param)

3) Pressure Outlet BC's (set with UDF and/or CONSTANT param)

Now, I need to determine/set the pressure on any of the 1D outlet boundaries, which I can do. Also I need to determine/set the pressure on any of a whole lot of 1D interior entities, of these I can calculate the pressure but I cannot figure out how to impose it across the entity. So, the problem(s):

1) I need to be able to IMPOSE a pressure value across any of my INTERIOR 1D threads.

2) When I calculate pressure across a 1D thread (with F_P()) I can obtain a "face averaged" value, but this is not accurate enough. in fact, if I "Report" on the pressure and choose "Facet Averaged" I get the same value as my UDF, but if I use "Vertex Averaged" I get the exact Pressure I expected (the value I need in my UDF).

Sorry for the long post, but this is been driving me mad for a long time now and I know there's quite a few fine Fluent users here that might have the answer straight away.

Thanks for your help! AL