Rheometry of Non-Newtonian Polymer Solution Using Microchannel Pressure Driven Flow

Abstract

This paper is concerned with the determination of the constitutive parameters of low concentrations of the complex fluid polyethylene glycol (PEO). Velocity fields of PEO solutions in a microfluidic T-junction have been measured for pressure driven flow using micron resolution particle image velocimetry. As the fluid is forced to turn the corner of the T-junction a range of shear rates, and therefore viscosities, is produced. Thus it is possible to establish the rheological profile from a single experiment. An inverse method used in conjunction with a finite element model was used to determine the constitutive parameters of the fluid, estimated to within 1.5 % error in all three cases considered.

Keywords

• microfluidics
• rheometry
• non-newtonian
• inverse problems
• pressure driven flow