Abstract: Two dimensional Navier-Stokes equation, Laplace equation and Possiou Boltzmann equations are employed to set up mathematical model for electroosmotic driven flow. Various flow shapes under different load conditions are discussed. The effects of the electrical double layer (EDL) thickness, extra electrostatic field and zeta electrical potential on the start time of electroosmotic drive flow are exploited based on numerical simulation. It is demonstrated that the start time mainly depends on the tube diameter and the other factors such as the EDL thickness and Zeta potential contribute little to the start time. Numerical simulation also predicted that the start time for reverse driven and zero load driven flow is less than 1 milli-second and it is about microseconds under extern loads. Finally, it is proved that the electroosmotic driven flow can realize positive and reverse direction flow through changing the Zeta potential and external electric fields directions. This is interesting for electroosmotic pump potential applications on biochips and microfluid dynamics.

Key words: Driving time, Electroosmotic flow, Meshless / meshfree method Modified Chorin-Teman (MCT) method