Some dynamical features of the turbulent flow of a viscoelastic fluid for reduced drag

Abstract

It is well known that the addition of minute amounts of long polymer chains to organic solvents, or water, can lead to significant turbulent drag reduction. In the present study, direct numerical simulations of turbulent channel flow of a viscoelastic fluid, at zero-shear friction Reynolds numbers up to of 1000, are analyzed. Both the mean and turbulent fields are studied, but with a primary focus on the turbulent stress and viscoelastic extra-stress (conformation tensor) fields in order to contrast the dynamics of each. An analysis of both the turbulent kinetic energy and the elastic energy budget is made, with emphasis on the interactive dynamics between the two fields.

Keywords:

• turbulent channel flow
• viscoelastic fluid
• drag reduction
• FENE-P model

Acknowledgments

[Acknowledgements] We would like to thank Dr. Remi Manceau for his insightful comments concerning the energy budgets. This research has granted access to the HPC (high-performance computing) resources of CCRT/CINES/IDRIS under the allocation i2011022277 made by GENCI (Grand Equipement National de Calcul Intensif). The data used herein were produced on the IBM Blue Gene/P computer Babel at the IDRIS/CNRS computing center, Orsay, France. The DNS database can be useful for a detailed investigation of the statistical properties of wall-bounded turbulence in the presence of diluted polymer. To facilitate such investigations, full cross-channel statistics can be publicly accessed online at http://lml.univ-lille1.fr/channeldata/