Hydrodynamics of micro-orifice flow is investigated numerically in this study. The effects of Knudsen number  orifice geometry  and Reynolds number  on the flow behaviour are studied. Results are presented for velocity, pressure, net pressure loss and discharge coefficient through an orifice meter. The numerical results are validated against available experimental data. It is found that the centreline axial velocity and the net pressure loss increase as Kndecreases. On the other hand, the discharge coefficient increases with increasing Kn.

micro-orifice, microchannel, numerical analysis, fully developed flow.