Statistics of particle pair separations in the elastic turbulent flow of a dilute polymer solutionT. Burghelea1, E. Segre2 and V. Steinberg1
1 Department of Physics of Complex Systems - Rehovot, 76100 Israel
2 Department of Physical Services, Weizmann Institute of Science Rehovot, 76100 Israel
received 29 July 2004; accepted in final form 15 September 2004
published online 27 October 2004
We investigate experimentally the statistics of a chaotic flow of a dilute polymer solution in a regime of elastic turbulence by using the Lagrangian coordinates approach. We show that due to flow smoothness at small scales the Finite Time Lyapunov Exponent (FTLE) technique can be successfully used to investigate the statistics of particle pair separations at different scales. We compare the measured FTLE with the characteristics of statistical description in the Eulerian coordinate presentation, namely the velocity correlation times and the average velocity gradients. We characterize the flow intermittency by measuring high-order moments of the statistics of the particle pair separations.
47.50.+d - Non-Newtonian fluid flows.
05.45.-a - Nonlinear dynamics and nonlinear dynamical systems.
47.52.+j - Chaos.
© EDP Sciences 2004