Electrokinetic and aspect ratio effects on secondary flow of viscoelastic fluids in rectangular microchannels

摘要: The secondary flow of PTT fluids in rectangular cross-sectional plane microchannels under combined effects electroosmotic and pressure driving forces is the subject present study. Employing second-order central finite difference method a very refined grid network, we investigate effect electrokinetic geometric parameters on pattern, strength average flow. In this regard, try to illustrate deformations recirculating vortices due change dimensionless Debye–Huckel zeta potential as well channel aspect ratio. We demonstrate that, presence thick electric double layers, significant alteration occurs pattern by transition from favorable adverse gradients. Moreover, it found that for polymer-electrolyte solutions with large Debye lengths, shape are generally dependent upon width-to-height ratio channel cross section. Also, inspections reveal sensitivity these quantities respect electrokinetic, rheological increases increasing absolute value velocity scale utilizing curve fitting results, several empirical expressions presented various parametric conditions. obtained relations other predictions high practical importance when dealing design microfluidic devices manipulate viscoelastic fluids.