Splitting of localized disturbances in viscoelastic channel flow

Abstract

We examine the response of an inertia-less viscoelastic channel flow to localized perturbations. A simplified model shows that the non-linear interaction between the velocity and elastic stress fields can split an initial pulsed disturbance into two separate pulses if the initial disturbance and the base elastic stress are sufficiently high. In accordance, we demonstrate that a transition to a pulse-splitting regime can be achieved experimentally. These results suggest a possible new direction for studying the elastic instability of viscoelastic channel flows at high elasticity through the growth of localized perturbations.

arXiv comment8 pages, 7 figures

References in corpus (8)

• Scaling of the turbulence transition threshold in a pipe
• A nonlinear elastic instability in channel flows at low Reynolds numbers
• Spectra of turbulence in dilute polymer solutions
• Sensitive dependence on initial conditions in transition to turbulence in pipe flow
• On the Turbulent Dynamics of Polymer Solutions
• Nonmodal amplification of stochastic disturbances in strongly elastic channel flows
• Flow Resistance and Structures in Viscoelastic Channel Flows at Low Re
• Elastically driven Kelvin-Helmholtz-like instability in planar channel flow