Advisor(s)
Abstract(s)
The lid-driven cavity flow is a well-known benchmark problem for the validation of new numerical meth- ods 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.
Description
Keywords
UCM model Oldroyd-B model; Purely-elastic flow instability Velocity regularization Finite-volume method Log-conformation tensor