Lid-driven cavity flow of viscoelastic liquids

TL;DR

This study investigates how viscoelastic properties influence flow instabilities in lid-driven cavity flows using advanced numerical methods, revealing critical conditions and effects of regularization under various aspect ratios and Deborah numbers.

Contribution

It introduces a finite-volume log-conformation formulation to analyze viscoelastic cavity flow instabilities across a wide parameter range, comparing results with experimental data.

Findings

Viscoelasticity significantly affects flow stability and onset of elastic instabilities.

Regularization of lid velocity influences steady-state flow behavior.

Critical Deborah numbers for instability onset are identified.

Abstract

The lid-driven cavity flow is a well-known benchmark problem for the validation of new numerical methods and techniques. In experimental and numerical studies with viscoelastic fluids in such lid-driven flows, purely-elastic instabilities have been shown to appear even at very low Reynolds numbers. A finite-volume viscoelastic code, using the log-conformation formulation, is used in this work to probe the effect of viscoelasticity on the appearance of such instabilities in two-dimensional lid-driven cavities for a wide range of aspect ratios (0.125 < height/length < 4.0), at different Deborah numbers under creeping-flow conditions and to understand the effects of regularization of the lid velocity. The effect of the viscoelasticity on the steady-state results and on the critical conditions for the onset of the elastic instabilities are described and compared to experimental results.