Spatiotemporal signatures of elastoinertial turbulence in viscoelastic planar jets
Sami Yamani, Y. E. A. RAJ, Tamer A. Zaki, Gareth H. McKinley, Irmgard Bischofberger
Abstract
The interplay between viscoelasticity and inertia in dilute polymer solutions at high deformation rates can result in inertio-elastic instabilities. We show how fluid elasticity has a nonmonotonic effect on jet stability depending on magnitude, creating two distinct regimes. The nonlinear evolution of these instabilities generates a state of elasto-inertial turbulence (EIT) with different spatiotemporal features than Newtonian turbulence. We use high-speed digital schlieren imaging and dynamic mode decomposition to quantify EIT and identify two modes of instability which can lead to a transition to turbulence at a lower Reynolds number with flow-aligned structures in the turbulent region.