Simulation of TCV-X21 and NSTX-U tokamak edge turbulence with Hermes-3*

Anomalous transport in the edge and divertor of high-power tokamak plasmas remains a critical uncertainty in predictive simulations of divertor and wall heat and particle fluxes, but 3D fluid turbulence models have now matured to the point where detailed comparisons with experiment can be performed. Over the last 5 years we have developed and applied the Hermes-3 code[1,2], building on BOUT++ to model self-consistently both turbulence and transport processes in tokamak diverted X-point and other geometries. We will present Hermes-3 simulations of the TCV-X21 diverted L-mode reference case[3], in both forward and reversed field configurations, and comparison to this open experimental dataset. Simulations have been performed for models of varying complexity, including an isothermal model, hot ion model, and hot ion model with fluid neutral gas. This enables a quantitative assessment of the impact of model assumptions on experimental agreement. Results will also be presented of turbulence simulations in NSTX-U double-null configurations. These simulations aim to inform to edge transport models, and to make predictions that can be tested in future experiments.