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Saturation of Turbulent Drag Reduction in Dilute Polymer Solutions

Roberto Benzi·Victor S. L'vov·Itamar Procaccia·Vasil Tiberkevich
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Abstract

Drag reduction by polymers in turbulent wall-bounded flows exhibits universal and non-universal aspects. The universal maximal mean velocity profile was explained in a recent theory. The saturation of this profile and the crossover back to the Newtonian plug are non-universal, depending on Reynolds number Re, concentration of polymer $c_p$ and the degree of polymerization $N_p$. We explain the mechanism of saturation stemming from the finiteness of extensibility of the polymers, predict its dependence on $c_p$ and $N$ in the limit of small $c_p$ and large Re, and present the excellent comparison of our predictions to experiments on drag reduction by DNA.

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Roberto Benzi, Victor S. L'vov, Itamar Procaccia, Vasil Tiberkevich. 2004-02-17. Saturation of Turbulent Drag Reduction in Dilute Polymer Solutions. https://doi.org/10.1209/epl%2Fi2004-10282-6

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