Ini my simulation, the chemical reaction only occur in part of the flow field, so I need to create block or patch to build the reaction region, but how to define this region as reaction only take place? It is possible in CFX 4.3, by user subroutine?

Thanks

You have to create a USER3D patch, either in the command file or in CFX-Build. In this region reaction can take place exclusively. For this you have to program some user fortran...

Astrid

I thought I must do it in the method you described. I have create the 3Dpatch, and plan to write user subroutine. But what is the main function or subroutine I should use? I have no idea after I read all the mannual about fortran subroutines. who can tell me some more detail? Thanks

windhair

If you have set up the reactions in command language, then use user fortran USRRAT. I would then set the 3D Patch to be all reagions where you want zero reaction. In USRRAT.F, set the reaction rate to zero for the given patch.

John