I am trying to educate myself on the lattice Boltzmann method to see if it may be useful for simulating some problems in plasma physics that I am interested in. One thing that strikes me is the (seemingly) universal adoption of BGK-style collision operators. Is the method intractable with more sophisticated collision operators like full Boltzmann (for neutral gases) or Fokker-Planck (for charged particles)? I understand that BGK-style operators are useful pedagogically for learning about the method, but does this also represent the state of the art?
1 Answer
An excellent starting point for a more in-depth look at different collision operators is Part 2, Chapter 10 of the book by Krüger et. al which introduces multiple-relaxation-time (MRT) and two-relaxation-time (TRT) collision operators.
These have been further refined by Karlin, Bösch and Chikatamarla (KBC) in an entropy maximizing manner, see their original publications:
Entropic multi-relaxation lattice Boltzmann scheme for turbulent flows
This is of course not the end of the story, depending on the application you are interested in you might use specialized methods/relaxation times, see for instance
or
just to name two publications tackling special use-cases.