Fluid Acceleration in the Bulk Turbulence of Dilute Polymer Solutions

TL;DR

This study experimentally measures Lagrangian accelerations in turbulent dilute polymer solutions, revealing decreased acceleration variance and increased autocorrelation time, while the acceleration distribution shape remains unchanged from Newtonian flows.

Contribution

It provides new experimental insights into how dilute polymers affect turbulence dynamics, particularly in acceleration statistics and temporal correlations.

Findings

Acceleration variance decreases in polymer solutions

Autocorrelation time of accelerations increases

Acceleration distribution shape remains unchanged

Abstract

We report experimental measurements of Lagrangian accelerations in the bulk of intense turbulent flows of dilute polymer solutions by following tracer particles with a high-speed optical tracking system. We observed a significant decrease in the acceleration variance in dilute polymer solutions. The shape of the normalized acceleration probability density functions, however, remain the same as in Newtonian water flows. We also observed an increase in the turbulent Lagrangian acceleration autocorrelation time in these dilute polymer solutions.