Numerical analysis of surface potential change on electroosmotic flow in a microchannel with using density-based WCSPH

We investigate the phenomenon of electrokinetics in microchannels. Electroosmotic is one of the four electrokinetic effects. Electroosmotic flow (EOF) is caused by the application of an electric field to an aqueous solution. The characteristics of the EOF depend on the nature of the surface potential distribution. EOF in microfluidic systems is limited to low Reynolds. As a result, species mixing in EOF systems is primarily due to diffusion. The surface heterogeneous of the microchannel walls causes the production of micro vortexes in the liquid. In this study, A two-dimensional microchannel is used to study the electroosmotic/pressure driven in Newtonian fluids. The equations governing the fluid flow in a rectangular microchannel are obtained based on the Lagrangian approach and using the density-based weakly compressible smoothed particle hydrodynamics (WCSPH) method. We have analyzed the vortexes due to surface potential heterogeneity and investigated increasing the surface potential on the flow. The results show that increasing the surface potential causes the vortexes to grow and strengthens the velocity and mixing fields more.

Keywords:

electroosmotic flow , Smooth particle hydrodynamics , Rectangular microchannels