Toward a structural understanding of turbulent drag reduction: nonlinear coherent states in viscoelastic shear flows
Fluid Dynamics
2009-11-07 v5 Chaotic Dynamics
Abstract
Nontrivial steady flows have recently been found that capture the main structures of the turbulent buffer layer. We study the effects of polymer addition on these "exact coherent states" (ECS) in plane Couette flow. Despite the simplicity of the ECS flows, these effects closely mirror those observed experimentally: Structures shift to larger length scales, wall-normal fluctuations are suppressed while streamwise ones are enhanced, and drag is reduced. The mechanism underlying these effects is elucidated. These results suggest that the ECS are closely related to buffer layer turbulence.
Keywords
Cite
@article{arxiv.physics/0112028,
title = {Toward a structural understanding of turbulent drag reduction: nonlinear coherent states in viscoelastic shear flows},
author = {Philip A. Stone and Fabian Waleffe and Michael D. Graham},
journal= {arXiv preprint arXiv:physics/0112028},
year = {2009}
}
Comments
5 pages, 3 figures, published version, Phys. Rev. Lett. 89, 208301 (2002)