Greifswald 2009 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

P: Fachverband Plasmaphysik

P 7: Theorie/Modellierung I

P 7.8: Vortrag

Dienstag, 31. März 2009, 15:00–15:15, HS Biochemie (groß)

Reynolds stress drive of zonal flows — •Niels Guertler and Klaus Hallatscheck — Max-Planck-Institut für Plasmaphysik, D-85748 Garching b. M.

Numerical self-consistent ITG-turbulence studies show a Reynolds stress driven zonal flow pattern with a robust radial scale length, different from the one with maximal initial growth rate. Modified states with different initial flow profiles always decay into the self-consistent zonal flow pattern. Wavekinetic theories quantitatively reproduce the stresses based on the observed flows in the simulations albeit fail to predict the self-consistent flow pattern itself. We use synthetic flows to validate and parameterize the analytic nonlinear relationship between stresses on one side and flows and turbulence level on the other. The objective of the fine-tuned nonlinear stress-flow response functional is to predict the time development and long term behavior of zonal flows including the experimentally observed turbulence bifurcations, with obvious implications for tokamak optimization.