Polymer heat transport enhancement in thermal convection: the case of Rayleigh-Taylor turbulence

TL;DR

This study demonstrates that adding polymers to Rayleigh-Taylor turbulent flows significantly enhances heat transport and accelerates mixing, supported by numerical simulations and a phenomenological interpretation.

Contribution

It provides the first numerical evidence that polymers can enhance heat transport in Rayleigh-Taylor turbulence, with a new interpretation based on small-scale turbulence reduction.

Findings

Heat transport increases up to 50% with polymers.

Polymer additives accelerate the growth of the mixing layer.

Numerical simulations confirm the heat transport enhancement.

Abstract

We study the effects of polymer additives on turbulence generated by the ubiquitous Rayleigh-Taylor instability. Numerical simulations of complete viscoelastic models provide clear evidence that the heat transport is enhanced up to 50% with respect to the Newtonian case. This phenomenon is accompanied by a speed up of the mixing layer growth. We give a phenomenological interpretation of these results based on small-scale turbulent reduction induced by polymers.