Re: [ESPResSo-users] setting a fixed value to a LB node

[Ulf Schiller]

On 12/23/2011 04:33 PM, Farnoosh Farahpoor wrote:
> Dear Espresso developers
> I have a question about "lbnode x y z set args" command. What is the
> meaning of this command? In the Espresso user guide it is mentioned that
> "The lbnode command allows to modify (set) single LB nodes."
> As I understand and see in my simulations the value of the "args" can
> change during the simulation but after calling this command it will be
> modified to our expected value but again it can change till the next call.
> Is there any possibility to give a completely fixed value to some
> quantities in a node? (something like "fix" option in part command)
>
> For example in my simulation I need some nodes in the entrance of a pore
> have fixed velocity in a some arbitrary direction.
>
> Thank you so much for your concern
> Farnoush

Hello Farnoush,

if I understand correctly, what you need are inlet/outlet boundary 
conditions. To the best of my knowledge, no such boundary conditions are 
implemented in the ESPResSo release at the moment. However, they should 
be fairly easy to implement using existing elements of the boundary 
conditions and the lbnode command. What I'm not so sure of is how to 
proof consistency and accuracy of Dirichlet type boundary conditions.

Regards,
Ulf

--
Dr. Ulf D. Schiller                        Building 04.16, Room 3006
Institute of Complex Systems (ICS-2)       Phone:   +49 2461 61-6144
Forschungszentrum Jülich, Germany          Fax:     +49 2461 61-3180

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