So long as the problems of interest are in "continuum" region, yes, you can use NS equation or LBE. The answer is negative if the problems are beyond "continuum" theory (连续介质理论).
So long as the problems of interest are in "continuum" region, yes, you can use NS equation or LBE. The answer is negative if the problems are beyond "continuum" theory (连续介质理论).