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arXiv · 2112.14672

Enhancement of drag and mixing in a dilute solution of rodlike polymers at low Reynolds numbers

Leonardo Puggioni·Guido Boffetta·Stefano Musacchio
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Abstract

We study the dynamics of a dilute solution of rigid rodlike polymers in a viscous fluid at low Reynolds number by means of numerical simulations of a simple rheological model. We show that the rotational dynamics of polymers destabilizes the laminar flow and causes the emergence of a turbulent-like chaotic flow with a wide range of active scales. This regime displays an increased flow resistance, corresponding to a reduced mean flow at fixed external forcing, as well as an increased mixing efficiency. The latter effect is quantified by measuring the decay of the variance of a scalar field transported by the flow. By comparing the results of numerical simulations of the model in two- and three-dimensions, we show that the phenomena observed are qualitatively independent on the dimensionality of the space.

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Leonardo Puggioni, Guido Boffetta, Stefano Musacchio. 2021-12-29. Enhancement of drag and mixing in a dilute solution of rodlike polymers at low Reynolds numbers. https://doi.org/10.1103/physrevfluids.7.083301

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