English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

In this paper, we present experimental results and reveal that strongperturbations are not necessary for elastic instability to occur instraight-channel, inertialess, visco-elastic flows at high elasticity. We showthat a non-normal mode bifurcation is followed by chaotic fluctuations,self-organized as stream-wise streaks, and elastic waves due to weakdisturbances generated by a small cavity at the center of the top channel wall.The chaotic flow persists in the transition, elastic turbulence, and dragreduction regimes, in agreement with previous observations for the case ofstrong perturbations at the inlet. Furthermore, the elastic waves we observepropagate in the span-wise direction, which allows to confirm the elastic waveslinear dispersion relation directly for the first time. In addition, thespan-wise propagating elastic wave's velocity depends on $\mathrm{Wi}$ with thesame scaling that was previously observed for stream-wise propagating waves,although their velocity magnitude is significantly smaller than what waspreviously observed for the stream-wise ones.

Non-modal elastic instability and elastic waves in weakly perturbed channel flow