Symmetric Boundary Conditions

Hi Dear All,
Can any one know about such a paper that discuss about symmetric boundary conditions in detail with equations.
Thanks in advance and Happy New Year to every body.
Best Regards

don’t know any paper, but I think that symmetric boundary conditions are straightforward in lattice boltzmann. take d2q9: on a wall, three distribution functions are unknown. on a symmetry wall, simply copy them from the mirror-reflected location.