Effect of a polymer additive on heat transport in turbulent Rayleigh-B\'enard convection

TL;DR

This study investigates how adding a polymer additive to water affects heat transport in turbulent Rayleigh-Bénard convection, showing a reduction in heat transfer efficiency at high Rayleigh numbers.

Contribution

It provides experimental evidence on the impact of polymer additives on heat transport in turbulent convection, a topic not extensively explored before.

Findings

Polymer additive reduces Nusselt number by up to 10%.

Effect observed over a wide Rayleigh number range.

Results suggest polymer alters turbulence and heat transfer mechanisms.

Abstract

Measurements of heat transport, as expressed by the Nusselt number $Nu$, are reported for turbulent Rayleigh-B\'enard convection of water containing up to 120 ppm by weight of poly-[ethylene oxide] with a molecular weight of $4\times10^6$ g/mole. Over the Rayleigh number range $ 5\times 10^9 \alt Ra \alt 7 \times 10^{10}$ $Nu$ is smaller than it is for pure water by up to 10%.