Experimental observation of the elastic range scaling in turbulent flow with polymer additives

Abstract

Minute amount of long chain flexible polymer dissolved in a turbulent flow can drastically change flow properties, such as reducing the drag and enhancing mixing. One fundamental riddle is how these polymer additives interact with the eddies of different spatial scales existing in the turbulent flow and in turn alter the turbulence energy transfer. Here we show how turbulent kinetic energy is transferred through deferent scales in the presence of the polymer additives. In particular, we observed experimentally the emerging of a new scaling range, referred to as the elastic range, where increasing amount of energy is transferred by the elasticity of the polymers. In addition, the existence of the elastic range prescribes the scaling of high-order velocity statistics. Our findings have important implications to many turbulence systems such as turbulence in plasmas or superfluids where interaction between turbulent eddies and other nonlinear physical mechanisms are often involved.

24pages,5 figures

References in corpus (4)

• Colloquium: Theory of Drag Reduction by Polymers in Wall Bounded Turbulence
• Direct numerical simulations of statistically steady, homogeneous, isotropic fluid turbulence with polymer additives
• Fluid Acceleration in the Bulk Turbulence of Dilute Polymer Solutions
• The Approach of Turbulence to the Locally Homogeneous Asymptote as Studied using Exact Structure-Function Equations