Velocity Initialization

[quarian_engineer]

Hello dear users,

Actually I have 2 questions but I wouldn't like to create 2 threads

1) Is there any possibility to initialize different velocities for different zones (e.g. for Inlet and not(inlet)) under "volume conditions" and disable the option "all cells"?
If I select just "zone 1" which is my Inlet and write v=(1,0,0) for it, code_saturne initialize also automatically "all cells" with whatever velocity, and this "all cells" condition overrides the initialization at the Inlet.



2) How to interpret next line (from listing)? CFL = 0.5516 and Fourier = 14.999 ?

criterion minimum maximum set mean spatial mean
--------------- -------------- -------------- -------------- --------------
Courant/Fourier 0.5516 14.999 7.7539 7.423


Thanks in advance
S.

[Luciano Garelli]

Hello,

1) You can define multiple zones to be initialized with different values (e.g. Different velocities). This is can be done in the GUI under the Volume Condition Tab -> Definition of volume regions. Here you can add multiple zones and specify a selection criterion for the cells (e.g. coordinates, group color, etc.). Also, you can define volume groups in Salome and then load from the preprocessor listing, like it is done with the BC's.

2) The Courant and Fourier are dimensionless numbers. In order to have stable numerical methods these values must range between a limited range. I think that this relation is used in the case of variable time stepping.

Regards,

Luciano