Constant velocity
 

Hi everybody,

I want to set a fixed velocity in some fluid cells in the middle of my mesh. I have tried to do this in "the subroutine "sormom.f" without success. Does anyone know how to do this?

Thanks,

Lennart

Re: Constant velocity
 

Lennart,

Hi and greetings again!

sormom is the exact right way to do this:
C-------------------------------------------------------------------------
C This subroutine enables the user to specify the momentum source
C term (per unit volume) in linearised form:
C
C Source in x direction = S1U-S2U*U, (N/m3)
C Source in y direction = S1V-S2V*V, (N/m3)
C Source in z direction = S1W-S2W*W, (N/m3)
C
C in an arbitray manner.
C
C ** Parameters to be returned to STAR: S1U,S2U,S1V,S2V,S1W,S2W,
C POROS
C
C-------------------------------------------------------------------------

What may not be obvious is what to set s1u to etc., this is best shown in sorent.f:

C-----------------------------------------------------------------------
C
C This subroutine enables the user to specify a source term (per unit
C volume) for enthalpy in linearized form:
C
C Source = S1P-S2P*T, (W/m3)
C
C in an arbitrary manner.
C
C If temperature is to be fixed to a given value T, then the
C following may be used:
C
C S1P=GREAT*T
C S2P=GREAT,
C
C where T can be a constant or an arbitrary function of the
C parameters in the parameter list.
C
C ** Parameters to be returned to STAR: S1P,S2P
C
C-------------------------------------------------------------------------

so combining the two means that if you set SU1 to great*desired velocity and SU2 to great it fixes the velocity. You need to set all three velocity components. Generally, this is done in and IF block based upon cell table (ICTID).

This is the info that would be supplied very quickly by an email to support@cd.co.uk

regards

Philip

Re: Constant velocity
 

Thanks alot Philip. It works perfectly.

Regards,

Lennart