Drift reduced Landau fluid model for magnetized plasma turbulence simulations in BOUT++ framework

Recently the drift-reduced Landau fluid six-field turbulence model within BOUT++ framework has been upgraded. In particular, this new employs a normalization, adds volumetric flux-driven source option, closure for parallel heat flux and Laplacian inversion solver which is able to capture n=0 axisymmetric mode evolution in realistic tokamak configurations. These improvements substantially extended model's capability study wider range of edge phenomena, are essential build fully self-consistent capable both transient (e.g., ELM, disruption) transport time-scale simulations.