A. Papukchiev, G. Lerchl, J. Weis, M. Scheuerer, H. Austregesilo
Thermal-hydraulic (TH) system codes are developed for the evaluation and improvement of the design and safety of nuclear facilities. Since the numerical modeling of the thermal-hydraulic processes is 1D in nature, these programs have only limited capabilities to predict in detail 3D flow phenomena like coolant mixing and thermal stratification. In contrast, computational fluid dynamics (CFD) software tools are used for 3D flow calculations with high spatial resolution. In order to realistically and efficiently simulate the thermal-hydraulic phenomena in a nuclear power plant (NPP), GRS has developed a methodology for the coupling of the TH system code ATHLET with the 3D CFD software ANSYS CFX. Within the European project NURISP, validation activities are performed for the 1D-3D code ATHLET – ANSYS CFX based on a Pressurized Thermal Shock (PTS) related experiment.