# [Technical] Beginner in Open Foam Meshing

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 November 15, 2012, 05:56 Beginner in Open Foam Meshing #1 Member   VS Join Date: Nov 2012 Posts: 86 Rep Power: 13 Hi all, i am a total beginner in Open Foam and i have some questions about basic stuff. i) How do you define magnitudes of Poo , Uoo ,ρ οο, Ma oo etc (oo for infinite) in your field , supposing you have a cylinder and its far field? ii) How do you normalize pressure,velocity and energy ? iii) How and where do i exactly define the kind of the equations i want to be solved (Euler or Navier - Stokes ? iv) Is there any way i could define a Courant number of my preference for all the solution and let the program compute the time steps in order this Courant number to be satisfied all the time? Any answer will be welcome

November 15, 2012, 16:36
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Lieven
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Quote:
 Originally Posted by VSass iii) How and where do i exactly define the kind of the equations i want to be solved (Euler or Navier - Stokes ?
You basically select the equations by the solver you use. Check out http://www.openfoam.com/features/standard-solvers.php for a list of the solvers that come with OpenFOAM by default. The small summary on the right-hand side of the table explains in which situation each solver can/should be used. If the set of equations you want to solve, is not covered by any of the default solvers, you can develop your own (one of the beautiful this about OpenFOAM). Easiest way to do this is to extend an existing one.

Quote:
 Originally Posted by VSass iv) Is there any way i could define a Courant number of my preference for all the solution and let the program compute the time steps in order this Courant number to be satisfied all the time?
Yes this is possible. In pimpleFoam for example (check out the tutorial), this Courant number-based time step control is implemented by default but you can easily extend other solvers with this functionality. Check out http://www.idurun.com/?p=371 for more information

 November 15, 2012, 16:48 #3 Member   VS Join Date: Nov 2012 Posts: 86 Rep Power: 13 10e+6 thanks mate

 Tags mesh and grid, mesh control, open foam