Simple framework for understanding the universality of the maximum drag reduction asymptote in turbulent flow of polymer solutions

Chang Feng Li, Radhakrishna Sureshkumar, Bamin Khomami

Research output: Contribution to journalArticlepeer-review

11 Scopus citations

Abstract

Self-consistent direct numerical simulations of turbulent channel flows of dilute polymer solutions exhibiting friction drag reduction (DR) show that an effective Deborah number defined as the ratio of polymer relaxation time to the time scale of fluctuations in the vorticity in the mean flow direction remains O(1) from the onset of DR to the maximum drag reduction (MDR) asymptote. However, the ratio of the convective time scale associated with streamwise vorticity fluctuations to the vortex rotation time decreases with increasing DR, and the maximum drag reduction asymptote is achieved when these two time scales become nearly equal. Based on these observations, a simple framework is proposed that adequately describes the influence of polymer additives on the extent of DR from the onset of DR to MDR as well as the universality of the MDR in wall-bounded turbulent flows with polymer additives.

Original languageEnglish (US)
Article number043014
JournalPhysical Review E - Statistical, Nonlinear, and Soft Matter Physics
Volume92
Issue number4
DOIs
StatePublished - Oct 21 2015

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Statistical and Nonlinear Physics
  • Statistics and Probability

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