Accuracy of momentum transport calculations in full-f gyrokinetic simulations

Abstract

Accuracy of momentum transport calculations in gyrokinetic simulations are studied using the full-f gyrokinetic Eulerian code GT5D. Toroidal angular momentum conservation is examined both in the axisymmetric limit without turbulent fluctuations and in turbulent tokamaks. As shown by Scott and Smirnov (2010 Phys. Plasmas 17 112302), the toroidal angular momentum is conserved when the simulation is based on modern gyrokinetic theory with an energetic consistency. The convergence of turbulent heat and momentum fluxes is examined by implementing higher-order drift and polarization terms. The results support the correctness of the turbulent momentum transport computed using conventional first-order gyrokinetics.