usrbcs for inlet boundary
 

Can anyone help me with this problem?

I am trying to set up a time varying boundary condition for an inlet of air from a diffusor. The diffusor is implemented as a patch with a time varying velocity of air. My problem is that I can´t associate the velocities defined in fortran with the patch in the command file, ie. i don´t get an inlet of air in the output file. The piece of code defined in Fortran USRBCS is:

CALL GETVAR('USRBCS','V ',IV)

CALL IPREC('BELUFTER1','PATCH','CENTRES',IPT,ILEN,JLEN, KLEN,

+ CWORK,IWORK)

DO 702 k=12,15

DO 701 j = 1,1

DO 700 i=7,7

inode =ip(i,j,k)

varbcs(iv,2,inode)=1.0 700 continue 701 continue 702 continue

The system is a multi fase system, and air is phase number 2. The inlet velocity is in the y-direction, normal to the tank bottom.

Regards Jesper Laursen, University of Aalborg, Denmark

Re: usrbcs for inlet boundary
 

Hi,
Why don't you use IPALL instead of using the IPREC utility subroutine? It would be something like this:
CALL GETVAR('USRBCS','V ',IV) CALL IPALL('BELUFTER1','*','PATCH','CENTRES',IPT,NPT,CW ORK,IWORK) DO 200 I=1,NPT INODE=IPT(I) VARBCS(IV,2,INODE)=1.0 200 CONTINUE
This may work. Good luck! cfd guy

Re: usrbcs for inlet boundary
 

Hi cfd guy.

Thanks for your reply. I found out that the problem was related to the way the patch was defined in the command file, but now it works.

Regards Jesper Laursen