I’m new to Palabos and BGK methods in general. I would like to simulate a gas expanding into vacuum. The gas originates at a surface where the density and flow speed is known.
My questions are:
(1) Can Palabos deal with rarefied gases?
(2) How do I set up a vacuum boundary condition? This should be a boundary where molecules can leave the domain while there is no flow inwards. The pressure is not necessarily zero.
Thank you for any feedback.