Abstract: In a perturbation analysis,a two-dimensional theoretical solution based on Navier-Stokes equations is constructed for gaseous slip flows in a micro-channel with different slip conditions.The micro-channel flow is investigated theoretically and numerically at various inlet pressure ratios,aspect ratios and fluid cases with several slip models.The influence of the rarefaction effect,thermal creep effect and slip conditions is emphasized.Simulations show that Kn is a key parameter in determining the magnitude of rarefaction effects while Re is a key parameter indicating the thermal creep.Excellent agreements with experimental results are observed in both theoretical and numerical results of low-velocity micro-channel flows at very large aspect ratios.

Key words: micro-channel, slip model, perturbation analysis, numerical investigation, Knudsen number