Elastic Alfven waves in elastic turbulence

Elastic waves and transition to elastic turbulence in a two-dimensional viscoelastic Kolmogorov flow.

We investigate the dynamics of the two-dimensional periodic Kolmogorov flow of a viscoelastic fluid, described by the Oldroyd-B model, by means of direct numerical simulations. Above a critical Weissenberg number the flow displays a transition from stationary to randomly fluctuating states, via periodic ones. The increasing complexity of the flow in both time and space at progressively higher v...

Two-dimensional elastic turbulence.

We report numerical evidence of elastic turbulence phenomenology in a two-dimensional periodic Kolmogorov flow. By direct numerical simulations of the Oldroyd-B viscoelastic model at very small Reynolds numbers, we find that above the elastic instability threshold the flow develops an elastic turbulent regime. We observe that both the turbulent drag and the Lyapunov exponent increase with the W...

Elastic waves in helical waveguides

Elastic turbulence in shear banding wormlike micelles.

We study the dynamics of the Taylor-Couette flow of shear banding wormlike micelles. We focus on the high shear rate branch of the flow curve and show that for sufficiently high Weissenberg numbers, this branch becomes unstable. This instability is strongly subcritical and is associated with a shear stress jump. We find that this increase of the flow resistance is related to the nucleation of t...

Elastic turbulence in 2D viscoelastic flows

It is well known that the addition of small amounts of long chain polymers produces dramatic effects on flowing fluids. A remarkable effect, recently observed experimentally, is the onset of ”elastic turbulence” in the limit of very low Reynolds number Re, provided elasticity is high enough [1]. In this regime, the polymer solution displays features typical of turbulent flows. Consequently, ela...