[vipinmace]

hi friends
i need a little favour asap.I've to apply a heat flux equation on the top edge of a horizontal plate(50 micro m * 50 micro m ) . I'm really new to fluent as i was working on APDL.I find it difficult to apply this function in APDL so i'm trying FLUENT . THIS IS MY PROBLEM

from starting of the edge ,up to a length of 20 micro meter , heat flux is
4.41 * e^(x^2 ) , where x represents length along the edge.
Then from 20 micrometer on wards upto the end of the edge equation is h*(T - 298 ), where h is constant and T is the temperature at the end of each iteration .

Please help me on this.

[macfly]

Hi,

I only have a partial answer.

What you need is a DEFINE_PROFILE macro, see the Ansys Fluent UDF Manual 15.0: Section 2.3.19.3. Example 1 - Pressure Profile. It's a straightforward example showing how you can apply a position-dependent profile.

The problem in your case is that you want to define a heat flux boundary condition when x <= 20 µm, and a convection boundary condition elsewhere. I'm not sure if you can do that. Maybe someone else can help you with that.

[ghost82]

You can do it, use define_profile as macfly suggested.
You have to work in pre-processing; if you want to apply 2 different boundary conditions on the top edge, simply split the top edge into two parts and assign 2 different names for that walls; then in fluent you will assign the udf for heat flux f(x) to one wall and the other boundary condition to the second one.

Daniele