Asymmetric capillary filling of non-Newtonian power law fluids

CLAUDIO L. A. BERLI; RAÚL URTEAGA

MICROFLUIDICS AND NANOFLUIDICS

SPRINGER HEIDELBERG

Lugar: HEIDELBERG; Año: 2014 vol. 1 p. 1 - 6

1613-4982

A theoretical analysis of the capillary-drivenimbibitions of non-Newtonian fluids in conical capillariesis presented. More precisely, the consequences of thevariation in the fluid viscosity with the shear rate areinvestigated by using the inelastic power law model. Novelfluid dynamic behaviors are predicted, notably the asymmetryof filling times measured from different ends of theconical tube. The effect is due to the anisotropy of the flowdomain and takes place with simple Newtonian fluidsindeed. It is quantitatively described how shear-thinningfluids increase the asymmetry, and shear-thickening fluidsdecrease it. Relevant applications in microfluidic rheometryare envisaged. In addition, these results are of interest inactive fields of research such as passive micropumping andmicroflow rectification, where the geometric design ofmicrochannels is the key to control fluidic operations.