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 raymond December 4, 2001 05:54

user subroutine of inlet boundary

I have a question about the user soubroutine of inlet boundary conditions. For in my simulation, the inlet value varies with position. For example, the inlet velocity at different location is different and I can define an equation to present the velocity, such as: u(y,z)=f(y,z) I know I can input the value var tablet.But it would take a lot of time, how can it be integrated to the user subroutine in STAR-CD?

Best regard

Raymond YIn

 john December 4, 2001 12:00

Re: user subroutine of inlet boundary

Since your inlet velocity is a fuction of position, then you should be able to do it very easily in BCDEFI. The Boundary positions are passed to BCDEFI (X,Y,Z).

 raymond December 4, 2001 22:38

Re: user subroutine of inlet boundary

Thanks a lot, I mis-understand the process of calling subroutine at first.

 Ethan December 5, 2001 19:54

Re: user subroutine of inlet boundary

What if the inlet velocity is also a function of time? V=V(x,y,z,t).. since Time is also a variable to be returned , so do you modify BCDEFI or other ways to do it ? Thank you very much ..

-Ethan

 Richard December 6, 2001 06:44

Re: user subroutine of inlet boundary

The boundary conditions at an inlet can be specified through BCDEFI as a function of position (the variables X, Y and Z indicate this) as well as time (the variable TIME indicates this). The conditions can be a function of lots of other things: have a look at the file "nom.inc" in the ufile subdirectory for a full nomenclature of user subroutines.

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