User defined and transient boundary conditions - profiles

Milan2013 · December 9, 2015, 11:23

Hello, hopefully someone can point me towards tutorials/links or give examples here, on the following 2 subjects:

1) I am interested to learn how I can set up a boundary condition of a variable (say velocity components, or other), say inlet profile of velocity or other quantity, as a function of 2 coordinates (say x,y, along a inlet cross-section of a geometry or similar). So, Ui=f(x,y), along a patch, or as Ui=f(x,y,z) in the domain.

2) In addition I wish to learn how can these boundary conditions be manipulated in transient manner. Say, the inlet velocity as a function of time t, either as a explicitly defined function within the solver, or by instructing the solver to read from specific OF user defined functions?...or by reading from .txt ASCII data with profiles at particular instants of time, which one can prepare in the case directory. So Ui=f(t) along a patch, or Ui=f(x,y, t)

Thanks!!!!

fabian_roesler · December 11, 2015, 04:38

These boundary conditions might be a good starting point:

uniformFixedValue
codedFixedValue
groovyBC from swak4Foam <-- My favourite

With groovyBC you can kind of program your own time and space demendand boundary condition. However you have to compile swak4Foam to be able to use it.

Check this link for more information:
https://openfoamwiki.net/index.php/Contrib/groovyBC
https://openfoamwiki.net/index.php/Contrib/swak4Foam

Cheers

Fabian

December 9, 2015, 11:23	User defined and transient boundary conditions - profiles	#1
Milan2013 Member Milan Join Date: Dec 2013 Posts: 38 Rep Power: 12	Hello, hopefully someone can point me towards tutorials/links or give examples here, on the following 2 subjects: 1) I am interested to learn how I can set up a boundary condition of a variable (say velocity components, or other), say inlet profile of velocity or other quantity, as a function of 2 coordinates (say x,y, along a inlet cross-section of a geometry or similar). So, Ui=f(x,y), along a patch, or as Ui=f(x,y,z) in the domain. 2) In addition I wish to learn how can these boundary conditions be manipulated in transient manner. Say, the inlet velocity as a function of time t, either as a explicitly defined function within the solver, or by instructing the solver to read from specific OF user defined functions?...or by reading from .txt ASCII data with profiles at particular instants of time, which one can prepare in the case directory. So Ui=f(t) along a patch, or Ui=f(x,y, t) Thanks!!!! hdariya likes this.

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December 11, 2015, 04:38		#2
fabian_roesler Senior Member Fabian Roesler Join Date: Mar 2009 Location: Germany Posts: 213 Rep Power: 18	These boundary conditions might be a good starting point: uniformFixedValue codedFixedValue groovyBC from swak4Foam <-- My favourite With groovyBC you can kind of program your own time and space demendand boundary condition. However you have to compile swak4Foam to be able to use it. Check this link for more information: https://openfoamwiki.net/index.php/Contrib/groovyBC https://openfoamwiki.net/index.php/Contrib/swak4Foam Cheers Fabian