March 2025 News
We have added a tutorial showing how to couple NekRS and MOOSE via Conjugate Heat Transfer (CHT), using a different set of boundary conditions. Up until now, the CHT coupling passed MOOSE wall conductive heat flux to NekRS as a Neumann condition, while NekRS passes wall temperature to MOOSE as a Dirichlet condition. Now, we also support flux-flux coupling, where NekRS passes to MOOSE as a Robin convective boundary condition. This option may be more stable and allow more extensive subcycling (more NekRS time steps per MOOSE time step).

Figure 1: Illustration of data transfers to couple NekRS to MOOSE for boundary heat transfer in a pin bundle.