Coupling time step

Submitted by Carlos Guamushig on Mon, 08/11/2014 - 23:07

Hello Everybody,

I need to know how to couple time step between liggghts and CFD? I modified deltaT in OpenFoam but I got the error "TS is too big for coupling".

Regards,

Carlos

Forums:

Wurdon | Wed, 08/13/2014 - 11:20

Hi Carlos,

the coupling interval is defined in CFD/constant/couplingProperties. The DEM timestep is defined in DEM/in.liggghts_resume.
I think you have to choose the timesteps according to: CouplingInterval x DEM timestep >= CFD timestep.

Best regards,
Philipp

Carlos Guamushig | Fri, 08/15/2014 - 22:22

Hi Philipp,

Thanks for your answer. I will try it.

Regards,

Carlos

cgoniva's picture

cgoniva | Wed, 08/20/2014 - 09:44

Dear Carlos,

I'd suggest the following procedure:
-Start with setting up the DEM part of the sim and see what DEM timestep you need there.
-then (depending on the dynamics) set the coupling interval between 1 and 500
-then set the CFD timestep accordingly

Your error message means that CFD detlaT is bigger than DEM deltaT * couplingInterval.

Cheers,
Chris