I have a question regarding the pressure-driven parabolic Poiseuille flow. The top and bottom walls are subjected to a zero-velocity bounce-back condition while the inlet and outlet boundaries enforce a pressure-driven fully-developed flow condition using the generalised periodic
boundary condition method. The walls to be located at grid solid nodes leads to strongly deviating results, while walls located midway between grid nodes makes the LB solution coincide with analytical parabolic profile. Increasing the resolution of the model does reduce the error significantly. How should I set the walls midway between grid nodes in OpenLB? Is it by default that the wall nodes are located at the grid solid nodes?
Poiseuille 2D simulation run
Simulation parameters: forced, bounceBack