Abstract: We employ the information preservation (IP) method and the direct simulation Monte Carlo (DSMC) method to calculate a plane Poiseuille flow from the continuum regime to the free-molecule flow regime.The Beskok-Karniadakis formula is corrected and kinetic factor of mass flow rate is re-fitted.A velocity distribution applicable to the entire flow regime is derived.

Key words: rectangular micro-channel, rarefied gas flow, information preservation method, velocity distribution