How to define PDE BC with UDF?
 

To all Fluent experts all over the world,

I am facing problem for defining BC involved PDE with UDF. Can somebody give me a hand? My PDE BC is

div(v)/div(y) = v + constant

where v = velocity in y direction

Thanks alot...

KKLAU

Re: How to define PDE BC with UDF?
 

Hi,

We can define it via UDF.

div(v)/div(y) is defined as C_DVDY(c, t) in UDF macro and this macro is for cell values .

So when we use this macro at a specified face via DEFINE_PROFILE , we have to define C0 and THREAD_T0 in the macro.

Thank you

FJ

Re: How to define PDE BC with UDF?
 

Hello, Before asking all those question you should read the fluent documentation in order to knwo what are the BC you can use, and then how to modify them using a UDF. To answer your first message about how to fix the BC div(v)/div(y) = v + constant. What I am proposing to you is to use a Velocity inlet. From there you can descretize your equation div(v)/div(y) = v + constant and easily calculate via UDF your velocity v. Then using a Velcoity Inlet you are gonna attached this velocity to your BC.

Thomas