Negative viscosity effect in largescale flows
Abstract
This study considers a largescale flow maintained by a smallscale periodic force field. If the field is essentially anisotropic, the system of smallscale eddies thereby generated turns out to be unstable to longwave disturbances, i.e., the effective viscosity of the corresponding largescale flow is negative. If the applied field is sufficiently isotropic, the longwave instability disappears so that the effective viscosity is positive.
 Publication:

Physics of Fluids
 Pub Date:
 April 1985
 DOI:
 10.1063/1.865025
 Bibcode:
 1985PhFl...28.1040S
 Keywords:

 Flow Stability;
 Liquid Flow;
 Secondary Flow;
 Stream Functions (Fluids);
 Two Dimensional Flow;
 Viscous Flow;
 NavierStokes Equation;
 Oscillating Flow;
 Small Perturbation Flow;
 Vortices;
 Fluid Mechanics and Heat Transfer