Generic mechanism of microturbulence suppression by vortex flows

Phys Rev Lett. 2009 Jul 3;103(1):015004. doi: 10.1103/PhysRevLett.103.015004. Epub 2009 Jul 2.

Abstract

The interaction between two-dimensional vortex flows and microturbulence is studied numerically using gyrofluid simulations. It is shown that, qualitatively different from usual mean flows, vortex flows can dramatically suppress microturbulence even with weak flow shear. A generic suppression mechanism is identified as the multiplied effect of both radial and poloidal mode couplings, which induce the formation of a new global mode. Furthermore, an oscillatory zonal flow is found to form through interaction between the vortex flows and microturbulence.