[fimbull]

When do i need the folowing equation?





And what does it mean?

is there Delta V the cell volume and Delta S a area from the cell surface? What means the f in sum_f.

Could somebody explain it with a cell with the size a*b*c

found it on:

https://openfoamwiki.net/index.php/Co

and also in CourantNo.C

tmp<volScalarField::Internal> Coi

                
(                                   
  byRho
  (
     (0.5*mesh_.time().deltaT())
     *fvc::surfaceSum(mag(phi))()()                                          
     /mesh_.V()
   )                               
);