Design of a Cross-Slot Flow Channel for Extensional Viscosity Measurements

Abstract

In this work we present an algorithm for optimal shape design of viscoelastic fluid flow. A finite‐volume viscoelastic code is coupled with the CONDOR optimizer [1] and an automated mesh generation and adaptation procedure, in order to find the shape of a given flow geometry, capable of achieving optimal performance. As an example of application we design an optimized cross‐slot microfluidic chip appropriate for measuring the extensional viscosity of dilute polymeric solutions. The microfluidic cross‐slot flow geometry is able to generate homogeneous elongational flow with regions of constant strain‐rate, a requirement to produce meaningful rheological measurements.