question about uds

tanven · October 24, 2009, 23:22

hello,everyone. I am new to Fluent. Here I have a question.

I have added an UDS(potential) . But I confused when I imposed the BC. There are two type of BC for UDS. One is "Specified flux",and the other is "Specified value".

And what I know is that "Specified flux" means "-diff*(grad(potential))".

Here is my question!

As for insulating wall, we should choose the BC with "Specified flux" equal to zero. Is it right?

Another question is that I imposed a constant current on another boundary, and this time how should I set the value of "Specified flux"?

Additional, Specified flux=-diff*(grad(potential)).

current density=-diff*(grad(potential)).

with the above two equations,

we can conclude that "Specified flux=current density", is it right?

tanven · October 27, 2009, 09:55

Is there anyone who can help me or give me some suggestion?

evangeline · July 5, 2015, 12:22

Hi dear, I encountered the same problem as yours.
How did you set the specified flux for your potential by UDF?

October 24, 2009, 23:22	question about uds	#1
tanven New Member Tanwei Join Date: Oct 2009 Posts: 2 Rep Power: 0	hello,everyone. I am new to Fluent. Here I have a question. I have added an UDS(potential) . But I confused when I imposed the BC. There are two type of BC for UDS. One is "Specified flux",and the other is "Specified value". And what I know is that "Specified flux" means "-diff(grad(potential))". Here is my question! As for insulating wall, we should choose the BC with "Specified flux" equal to zero. Is it right? Another question is that I imposed a constant current on another boundary, and this time how should I set the value of "Specified flux"? Additional, Specified flux=-diff(grad(potential)). current density=-diff*(grad(potential)). with the above two equations, we can conclude that "Specified flux=current density", is it right?

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October 27, 2009, 09:55		#2
tanven New Member Tanwei Join Date: Oct 2009 Posts: 2 Rep Power: 0	Is there anyone who can help me or give me some suggestion?

July 5, 2015, 12:22		#3
evangeline New Member xing lu Join Date: Jun 2015 Posts: 1 Rep Power: 0	Hi dear, I encountered the same problem as yours. How did you set the specified flux for your potential by UDF?