Key words: Rectangular microchannels, pressure drop, friction factor, single-phase flow.

Abstract: This paper focuses on investigating, numerically, the laminar single-phase flow through rectangular microchannels with hydraulic diameters varying from 150μm to 550μm, with aspect ratio changing from 0.3 to 0.97. The numerical model employs the three dimensional Navier-Stokes equations to simulate the flow behavior in microchannels. The numerical solution is obtained by discretizing the governing equations using the finite-element method (FEM). The numerical simulations are done on a range of the Reynolds number (Re) varied from 1 to 400. For the isotherm and laminar single-phase flow model, the liquid water is used as the testing fluid. The viscous dissipation, the pressure work and the gravity are neglected. In this study pressure drop shows an agreement with the theoretical results for rectangular channels. However, for Reynolds number range ≤ 100, the friction factor data were found less than the predicted theoretical data presented by Shah and London in rectangular channels.