when is fix couple/cfd needed?

Submitted by rqwang on Fri, 11/09/2012 - 18:21

Hi cfdemers,

I modified ErgunTestMPI case to my numerical setup. I only changed the geometry in polymesh and boundary conditions in 0.
But I found the command fix couple/cfd is needed.

Could anyone tell me when this command is needed and where I can specify it?

Thanks.

rq

Forums:

alice's picture

alice | Mon, 11/12/2012 - 09:00

Hello,
the command you are referring to is responsible for the coupling one the DEM-side and therefore can be found in in.liggghts_resume. It consists of two lines, please have a look at one of the tutorial cases to see their exact form in application.
Cheers,
Alice

rqwang | Mon, 11/12/2012 - 14:41

I was confused, because in the tutorial ErgunTestMPI, there is no such command. But my case requires it. It's OK that I added them in my liggghts input file, but I would be happy if I know when they should be added and when they don't.

Thanks.

rq

alice's picture

alice | Tue, 11/13/2012 - 09:07

Hello,
this confuses me a bit ;)
I do not know which CFDEM-version you are using, but in the latest one you will find the line in in.liggghts_resume (and only there, as in.liggghts_init is responsible for some preliminary DEM-only calculations).
So whenever youo want a coupling being carried out, you will need these lines.
Cheers,
Alice