# UDF-code

Member

Hi

How can I write a UDF-code for inlet temperature( fully developed profile) with conjugate heat analysis? I have two inlets ( two fluid domains and solid domain).

Also, how can I write a code for velocity and k-e profiles, by making a fully developed flow at inlet with copying the face mesh of outlet profile to inlet?

Best regards

A.A

• GermanyForum Coordinator

Please check the manual for DEFINE_PROFILE examples. Better to use Fluent Expression (example in the User'Guide to code a parabolic velocity profile)

• Member

I have checked the manual, but no thing is helpful. The geometry is non-circular pipe. Perhaps, the velocity profile is not complicated. However, the periodic temperature profile for both inlets( for each fluid) is complicated since I am doing conjugate heat analysis between two fluids and interface solid domain.

If you are looking for these detailed profile files, I'd say run a quick simulation with streamwise periodic flow conditions. This will give you the necessary profiles which you can use in your final simulation.

Thanks.

Karthik

• Member

Your way can be done for velocity field or pressure, but how about the temperaure?

• Member

You can see in the attached for what I am talking about. I have a counter flow between two fluids which are separated by a wall (solid domain). I'm trying to write a UDF , in which I am coping the velocity of the outlet face to inlet. But I got more problem in that code.

So, I am looking for better way to solve this problem. or how I can copy the velocity at outlet face to inlet to make as periodic. Another issue is with Temerature.

Best regards.

Abbas

• UKForum Coordinator

For velocity you can use a profile. If you fix the temperature in that way you'll find both sides have the same value as you'll be modelling the equilibrium condition.

• Member

The wall temperature is variant linearly. It is not constant. If it is constant, then it is easy to model the problem as separated domains.

Can I apply a periodic(UDF) temperature on both ends for each fluid?

Regards

Abbas

• UKForum Coordinator

You can, but think through the temperature field.

If in=out on both sides what temperature will that become?

• Member

Yes, you are right. but I think to apply a temperature profile at the inlets instead of periodic temperature.

• UKForum Coordinator

OK, so you can use a profile. But, you'll still need to figure out at what value.