Multi-scale problems of heat and mass transfer in nuclear industry

This paper presents a review of the results obtained in OKB «GIDROPRESS» taking into account the experience gained in the field of numerical modeling of heat and mass transfer in various nuclear power facilities. The benefits of using CFD technology in the NPP design is the ability, based on a limited number of experimental data, to study in detail the heat and mass transfer processes in the facilities in order to confirm or improve design solutions at the advanced scientific and technical level. A number of problems are presented, for solution of which the modern numerical methods of computational hydrodynamics with high-performance computer technology were used. New possibilities of computational modeling with the use of modern supercomputer computing technologies, as well as accompanying computational complexity and difficulties of analysis of results are shown. Examples of use of the considered technology for modeling experimental rigs and full-scale objects under different operating conditions are given. The automatic post-processing of the results is shown. The procedure allows to analyze large problems with mesh size up to 1 billion control volumes by integral parameters, such as mass flow distribution at the core inlet and outlet, distribution of coolant heat-up over the core fuel assemblies, etc.