The Effects of Nonuniform Thermal Boundary Condition on Thermal Stress Calculation of Water-Cooled W/Cu Divertors

The thermal boundary condition has very important effects on the accuracy of thermal stress calculation of a water-cooled W/Cu divertor. In this paper, phase-change heat transfer was simulated based on the Euler homogeneous phase model, and local differences of liquid physical properties were considered under one-sided high heating conditions. The steady-state temperature field and thermal stress field under nonuniform thermal boundary conditions were obtained through numerical calculation. By comparison with the case of traditional uniform thermal boundary conditions, the results show that the distribution of thermal stress under nonuniform thermal boundary conditions exhibits the same trend as that under uniform thermal boundary conditions, but is larger in value. The maximum difference of maximum von Mises stress is up to 42% under the highest heating conditions. These results provide a valuable reference for the thermal stress calculation of water-cooled W/Cu divertors.