Immersed boundary LBM (complex geometry)


I’ve managed to implement LBM with D3Q15 on a regular grid.
My question is, which is the state of the art approach in order to model complex boundaries (geometries), i.e. when a curved boundary intersects the regular lattice grid?
Thank you!

I am trying to simulate a 3D lid-driven cavity flow using d3q15 lattice. I will be grateful if you could provide me with the closed form equations of the different distribution functions for no-slip velocity boundary condition at different boundaries. Or if you can provide any information on where I can find them.