Re: [ESPResSo-devel] incorrect velocity scaling for slip lbboundary

[Ivan Cimrak]

Thanks a lot for the update....

Ivan


On 25/01/2018 15:00, Kai Szuttor wrote:
> Hi Ivan,
>
> This issue is on our agenda. I already had a look but could not find the source 
> of the wrong velocity.
> We hope to be able to resolve it soon.
>
> Best,
>
> Kai
>
> > On 25. Jan 2018, at 14:43, Ivan Cimrak <address@hidden> wrote:
> >
> > Hi guys,
> >
> >
> > In December I posted here comment on incorrect scaling of velocity at 
> > lbboundary. Kai checked this on GPU, it was correct, however for CPU it is 
> > still wrong. Please see my mail below. I am adding a sample script.
> >
> >
> > Thanks,
> >
> > Ivan
> >
> >
> > On 08/12/2017 11:08, Kai Szuttor wrote:
> > > Hi Ivan,
> > >
> > > I just checked your test with GPU LB and there the velocity comes out
> > > correct, so it seems to be a problem of CPU LB.
> > >
> > > I'll have a look.
> > >
> > > Cheers,
> > >
> > > Kai
> > > On Fri, Dec 08, 2017 at 08:56:03AM +0000, Ivan Cimrak wrote:
> > > > Hey guys,
> > > >
> > > >
> > > > Is it possible to have incorrect velocity scaling for slip boundary
> > > > conditions? I took an example script (attached) from section "10.10. Setting
> > > > up boundary conditions" from ESPResSo online documentation:
> > > >
> > > > http://espressomd.org/html/doc/lb.html
> > > >
> > > > I added the printing of the velocity near the right slip wall and after
> > > > reaching steady state it shows almost 100 times larger velocity as it is
> > > > supposed to be (0.941 or so instead of 0.01). This behaviour is linked with
> > > > lb timestep which was 0.01. Increasing to timestep=0.1 gives only 10times
> > > > higher velocity.
> > > >
> > > >
> > > > Could you comment on this?
> > > >
> > > >
> > > > Many thanks,
> > > >
> > > > Ivan
> > <test_from_documentation.py>