A simple question

I was working on the simulation of a flute using LBM, therefore i was simulating “air”, a compressible fluid, but the computational cost was too large ( 2400x750 lattice size to ensure stability of the BGK model ). So I change my objectives, and i want to validate the model that i have with some physical data, but the data that i collect was using water (There’s no equipment to get data from gases), a incompressible fluid. So at the start of the BGK-LBM the density is calculed.

Should I ommit that step, and leave the density constant?

I know that this is a trivial and basic question, but i didn’t find anything about that on Wolf-Gladow neither on Sukop.

Thanks for your time


No, you can’t omit this step. The density must be computed anyway, because it is used to reflect pressure variations. Your question is answered in-depth in the answer to Kaff’s question.

Thanks Jlatt,