Reply To: Multicomponent flow
defineUBouzidi is not a method of the super lattice but a free function that accepts the super lattice (
sLatticeTwo in your case) as its first argument.
So this should look something like (I can not ensure that this works in this way exactly as I do not know your whole code):
defineUBouzidi(sLatticeOne, superGeometry, 5, poiseuilleU);
defineUBouzidi(sLatticeTwo, superGeometry, 5, poiseuilleU);