Multiscale analysis of heat transfer in coated fuel particle compacts - Application to the HTTR

Heat conduction in coated fuel particles compacts is modeled for a nuclear application. In order to take into account the multi-scale features of the heterogeneous material, the homogenization method is used to evaluate macro- as well as micro-scale temperature fluctuations. The method is validated against direct computations of the temperature field for simple configurations, and is shown to be robust with respect to the micro-scale lattice used in the homogenization procedure. Non-linear effects due to the temperature dependence of thermal conductivities are taken into account in the model.