“…However, the simulation results are often noisy, and it is difficult to compute transient details (time dependent states), especially if the probability density function (pdf ) is desired. In recent years, deterministic solvers to the BP system were considered in the literature, see for example [1,2,3,4]. These methods provide accurate results which, in general, agree well with those obtained from DSMC simulations, sometimes at a comparable or even less computational time.…”