Elastic turbulence (ET) is a unique chaotic state driven by polymer dynamics alone and occurring in inertia-less flows under certain conditions. Turbulent drag reduction (TDR) is observed at super-critical Reynolds number flows through well-understood flow-turbulence structure interactions. So far, the turbulence community sees ET and TDR as distinct states of turbulence. Neither state enjoys the strong theoretical understanding than Newtonian turbulence has. A recently discovered turbulent state, elasto-inertial turbulence (EIT), occupying the Reynolds number space between ET and TDR, suggests that ET and TDR are linked and this link could be a significant piece missing in the theory of TDR.
To search for direct relation between ET and TDR and prove of the aforementioned hypothesis, experiments we focused on a setup of a flow between two cylindrical obstacles in a micro-channel flow. In the same setup we study the dynamics of ET, EIT and TDR in unbounded flow configuration. It allows first to investigate ET in fairly homogeneous vortex flow. Then by using polymer solutions of different viscosities in a wide range of their variations we are able to scan the Wi and Re parameter plane up to several hundred and to study the various turbulent states and transition between them