[ESPResSo-users] Lattice Boltzmann Boundaries

[Martin Kaiser]

Hi everybody,

I have a question regarding the box boundaries in a Lattice Boltzmann 
Simulation. The situation is as follows:

I took the code from the LBM  Tutorial Part 1, where there is a square tube 
with a sphere in the centre. The flow is created just as in the sample code. My 
problem is that, for what I need to do, I need to change the parameters so that 
I see vortices behind the sphere (increasing Reynolds number). Due to the 
periodic boundary conditions on the open ends of the tube, the “tail” that is 
created behind the sphere re-enters the simulation box from the other side and 
thus perturbing my system in an unwanted way.

Is there a smart way in ESPRESSO to bypass this, creating an ,sort of, inlet 
and outflow boundary conditions on the open ends of the tube?

I hope that my issue is clear, all the best,
Martin