Momentum‐energy transport from turbulence driven by parallel flow shear

The low‐frequency E×B turbulence driven by the shear in the mass flow velocity parallel to the magnetic field is studied using the fluid theory in a slab configuration with magnetic shear. Ion temperature gradient effects are taken into account. The eigenfunctions of the linear instability are asymmetric about the mode rational surfaces. Quasilinear Reynolds stress induced by such asymmetric fluctuations produces momentum and energy transport across the magnetic field. Analytic formulas for the parallel and perpendicular Reynolds stress, viscosity, and energy transport coefficients are given. Experimental observations of the parallel and poloidal plasma flows on the Texas Experimental Tokamak Upgrade (TEXT‐U) are presented and compared with the theoretical models.