title: Mixing of non-Newtonian fluids in wavy serpentine microchannel using electrokinetically driven flow.
abstract: A numerical investigation is performed into the mixing performance of electrokinetically driven non-Newtonian fluids in a wavy serpentine microchannel. The flow behavior of the non-Newtonian fluids is described using a power-law model. The simulations examine the effects of the flow behavior index, the wave amplitude, the wavy-wall section length, and the applied electric field strength on the mixing performance. The results show that the volumetric flow rate of shear-thinning fluids is higher than that of shear-thickening fluids, and therefore results in a poorer mixing performance. It is shown that for both types of fluid, the mixing performance can be enhanced by increasing the wave amplitude, extending the length of the wavy-wall section, and reducing the strength of the electric field. Thus, although the mixing efficiency of shear-thinning fluids is lower than that of shear-thickening fluids, the mixing performance can be improved through an appropriate specification of the flow and geometry parameters. For example, given a shear-thinning fluid with a flow behavior index of 0.8, a mixing efficiency of 87% can be obtained by specifying the wave amplitude as 0.7, the wavy-wall section length as five times the characteristic length, the nondimensional Debye-Huckel parameter as 100, and the applied electric field strength as 43.5 V/cm.
authors.affiliation: Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan, Republic of China.
authors.forename: Ching-Chang
authors.initials: CC
authors.lastname: Cho
authors.forename: Chieh-Li
authors.initials: CL
authors.lastname: Chen
authors.forename: Cha'o-Kuang
authors.initials: CK
authors.lastname: Chen
mesh_terms: D003198:Computer Simulation; D004574:Electromagnetic Fields; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D008962:Models, Theoretical