Re: [ESPResSo-users] WG: poiseuille flow with linear part at first and last grid

[Owen Hickey]

I would just like to point out that the print velocity using spacial
coordinates simply interpolates linearly between LB nodes, setting all
boundary nodes to zero. If you zoom in, even the "parabolic" parts are
just made up of linear segments. The velocity used for coupling to MD
particles assumes that the velocity is zero where you actually specify
the boundary using the lbboundary command, Unfortunately there is no
simple way of printing out the interpolated velocity used in the
coupling.

Owen

On Wed, May 20, 2015 at 2:04 PM, Ulf Schiller <address@hidden> wrote:
> On 20/05/15 13:00, Holst, Lena wrote:
>> I have run the script poiseuille.tcl from the espresso samples. The
>> result is a flow which looks like a poiseuille flow, but with a linear
>> part in the first and last grid along the x, y and z axis.
>
> This is expected as the effective boundary lies approximately halfway
> between the grid points.
>
> Best wishes,
> Ulf
>
> --
> Dr Ulf D Schiller
> Centre for Computational Science
> University College London
> 20 Gordon Street
> London WC1H 0AJ
> United Kingdom
>
> Phone: +44 (0)20 7679 5300
>