Effect of variable slip boundary conditions on flows of pressure driven non-Newtonian fluids

✍ Scribed by G.G. Pereira

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 720 KB
• Volume: 157
• Category: Article
• ISSN: 0377-0257
• DOI: 10.1016/j.jnnfm.2008.11.012

✦ Synopsis

In microfluidic devices it has been suggested a scheme for enhancing the mixing of two fluids is to use patterned, slip boundary conditions. This has been shown to induce significant transverse flow for Newtonian fluids [S.C. Hendy, M. Jasperse, J. Burnell, Effect of patterned slip on micro-and nanofluidic flows, Phys. Rev. E 72 ( 2005) 016303]. Here we study the effect of patterned slip on non-Newtonian fluids. Using a power-law model it is shown for shear-thickening fluids patterned slip can induce significant transverse flows comparable in size to those produced for Newtonian fluids. However, for shear-thinning fluids this transverse flow is suppressed. We predict a convenient way to increase the transverse flow for shear-thinning fluids is to use a patterned slip boundary condition coupled to a sinusoidally timevarying pressure gradient. This system is studied using a simple linearized White-Metzner model which has a power-law viscosity function [R.B.