Re: [ESPResSo-devel] [bug #44133] Temperature in LB_GPU is too high

[Florian Weik]

For the testcase in question dt*gamma = 0.01, so i guess it does not run into that problem.

On Fri, Jan 30, 2015 at 5:45 PM, Marcello Sega <address@hidden> wrote:

Hi,

If I remember right, once I noticed that with "high" frictions the
momentum that is transferred back to the fluid tends to diverge with
time. This could be a limitation introduced by the fact that we are
approximating the forces (as Ulf commented once, one should use
midpoint or Crank-Nicolson approximation instead).  For proper
integration, anyway, one should have dt * gamma << 1. In this regime
the fluid should have no problem. Did you check that ?

M.

On Fri, Jan 30, 2015 at 5:38 PM, Joost de Graaf <address@hidden> wrote:
> Follow-up Comment #1, bug #44133 (project espressomd):
>
> We just checked how the deviations depend on the particle friction. For a
> friction of 10 (instead of 2), the fluid temperature is unaffected, but the
> particle temperature deviation is 5 times higher (and closer to the higher
> fluid temperature). This suggests that the error happens in the fluid and the
> particles are just perturbed from their proper temperature by the coupling
> with the improperly thermalized fluid.
>
>     _______________________________________________________
>
> Reply to this item at:
>
>   <http://savannah.nongnu.org/bugs/?44133>
>
> _______________________________________________
>   Message sent via/by Savannah
>   http://savannah.nongnu.org/
>
>

--

Florian Weik

address@hidden
++49 157 85939252