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How to define PDE BC with UDF?

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Old   April 6, 2004, 00:10
Default How to define PDE BC with UDF?
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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...

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Old   April 6, 2004, 02:28
Default Re: How to define PDE BC with UDF?
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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


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Old   April 6, 2004, 08:35
Default Re: How to define PDE BC with UDF?
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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.

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