A KIND OF SINGULAR PERTURBATION METHOD FOR SOLVING THE BOLTZMANN EQUATION WITH SMALL KNUDSEN NUMBER

A singular perturbation method is used to remove secular terms in Hilbert expansion and Enskog expansion of the normal solution and those in Grad expansion of the " initial layer" solution of Boltzmann equation( B.e.) . Solving B. e . in the "boundary layer " is reduced to solving a set of linear algebraic equations.