TY - JOUR

T1 - The interplay between Reynolds stress and zonal flows

T2 - Direct numerical simulation as a bridge between theory and experiment

AU - Vergote, M.

AU - Van Schoor, M.

AU - Xu, Y.

AU - Jachmich, S.

AU - Weynants, R.

PY - 2006/4/1

Y1 - 2006/4/1

N2 - We describe the results of a measurement campaign on the CASTOR tokamak where the drive of flows and zonal flows by Reynolds stress was investigated by means of a dual probe head system allowing us to measure the properties of the electrostatic turbulence and the rotation velocities at the same location and at the same moment. We compare these experimental results with a turbulence model linked to a one dimensional fluid model describing the electrostatic turbulence and its influence on the background flow. The turbulence is simulated locally on the basis of the Hasegawa-Wakatani equations, completed with magnetic inhomogeneity terms. In the fluid model the toroidal geometry is correctly taken into account, while various sources and sinks like viscosity, interaction with neutrals, Reynolds stress and electric current induced by biasing are included. The good agreement of the predicted flow with the measured one demonstrates that in a pure cylindrical geometry the modelled strength of Reynolds stress acceleration of flow is overestimated.

AB - We describe the results of a measurement campaign on the CASTOR tokamak where the drive of flows and zonal flows by Reynolds stress was investigated by means of a dual probe head system allowing us to measure the properties of the electrostatic turbulence and the rotation velocities at the same location and at the same moment. We compare these experimental results with a turbulence model linked to a one dimensional fluid model describing the electrostatic turbulence and its influence on the background flow. The turbulence is simulated locally on the basis of the Hasegawa-Wakatani equations, completed with magnetic inhomogeneity terms. In the fluid model the toroidal geometry is correctly taken into account, while various sources and sinks like viscosity, interaction with neutrals, Reynolds stress and electric current induced by biasing are included. The good agreement of the predicted flow with the measured one demonstrates that in a pure cylindrical geometry the modelled strength of Reynolds stress acceleration of flow is overestimated.

UR - http://www.scopus.com/inward/record.url?scp=33645084522&partnerID=8YFLogxK

U2 - 10.1088/0741-3335/48/4/S06

DO - 10.1088/0741-3335/48/4/S06

M3 - Article

AN - SCOPUS:33645084522

SN - 0741-3335

VL - 48

SP - S75-S86

JO - Plasma Physics and Controlled Fusion

JF - Plasma Physics and Controlled Fusion

IS - 4

ER -