Shearing rate of time-dependent E×B flow

• DOI: 10.1063/1.873331
• Publication Date: 2002-07-26T12:46:20Z
• Authors: T. S. Hahm; M. A. Beer; Z. Lin; G. W. Hammett; W. W. Lee; W. M. Tang
• Keywords: Shearing (physics); Eddy

Theory of E×B shear suppression turbulence in toroidal geometry [Phys. Plasmas 2, 1648 (1995)] is extended to include fast time variations the flows often observed nonlinear simulations tokamak turbulence. It shown that quickly varying components flows, while they typically contribute significantly instantaneous shearing rate, are less effective than slowly suppressing This because flow pattern changes before eddies get distorted enough. The rate capturing this important physics analytically derived and estimated from zonal statistics gyrofluid simulation. provides new insights into understanding recent gyrokinetic yield a reduced, but not completely quenched, level presence turbulence-driven flows.