Toroidal gyrofluid equations for simulations of tokamak turbulence

Abstract
A set of nonlinear gyrofluid equations for simulations of tokamak turbulence are derived bytaking moments of the nonlinear toroidal gyrokinetic equation. The moment hierarchy is closed withapproximations that model the kinetic effects of parallel Landau damping, toroidal drift resonances,and finite Larmor radius effects. These equations generalize the work of Dorland and Hammett[Phys. Fluids B 5, 812 (1993)] to toroidal geometry by including essential toroidal effects. Theclosures for...