Numerical investigations of electro-osmotic flows in triangle microchannels

Small triangle channels are frequently encountered in microelectromechanical systems (MEMS). In this paper, the mixed electro-osmotic/pressure-driven flows in triangle microchannels are numerically investigated. Poisson and Navier-Stokes equations were numerically solved employing the Galerkin algorithm. The accuracy of the numerical algorithm was validated by refining the grids and using Richardson extrapolation. The numerical results show the mass flux of electrolytic solution increases with the increase of imposed positive pressure gradient. At small pressure gradients, the relative mass flux increment induced by the imposed positive pressure gradient is sensitive to the change in the pressure gradient. However, when the pressure gradient increases beyond a critical value, the relative mass flux increment increases smoothly with the increase of pressure gradient. It is also found that the mass flux increases with increasing the length ratio, kappa D-h, at a given pressure gradient. (C) 2007 Elsevier Ltd. All rights reserved.