Elastic turbulence in a polymer solution flow

Elastic vs. inertial instability in a polymer solution flow

– The interrelation between elastic and inertial effects in destabilizing the flow of a polymer solution is studied experimentally. To achieve this goal, solution elasticity is varied by three orders of magnitude and a diagram of the flow states in a Couette-Taylor system is obtained. The regions of purely elastic and purely inertial flow instabilities and a crossover region between them are ch...

The rheology of polymer solution elastic strands in extensional flow

Elastic turbulence in curvilinear flows of polymer solutions

Following our first report (A Groisman and V Steinberg 2000 Nature 405 53), we present an extended account of experimental observations of elasticity-induced turbulence in three different systems: a swirling flow between two plates, a Couette–Taylor (CT) flow between two cylinders, and a flow in a curvilinear channel (Dean flow). All three set-ups had a high ratio of the width of the region ava...

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...

Buckling instabilities in dilute polymer solution elastic strands

A microfluidic oscillatory cross-slot flow is used to visualize birefringent strands in dilute polystyrene solutions with high temporal resolution, focusing specifically on reversals in the flow direction. Due to polymer conformation hysteresis, the elastic strands are slow to relax and demonstrate a compressive modulus, resulting in a “buckling instability.” An elastic loop of birefringence fo...