OpenFOAM solver development for pressure waves propagation in liquid metals

In the environment of liquid metal (LM) breeding blanket (BB) technologies, the structural integrity of coolant tubes is at risk due to the concurrent effects of high-pressure, elevated temperatures, corrosive action of the metal breeder under magnetohydrodynamics (MHD) conditions, and intense neutron bombardment. Such conditions can lead to in-box Loss of Coolant Accidents (LOCAs), characterized by the intrusion of high-pressure coolant (helium or water) into regions of lower pressure LM, thus endangering the blanket structures and leading to the potential escape of radioactive material. This scenario establishes in-box LOCA as a pivotal concern in the design protocols for BB safety. The numerical tools employed for simulating the intricate physics of these interactions are constrained by their spatial resolution capabilities. Given the complexity of the phenomena, a three-dimensional approach is essential for accurately addressing in-box LOCA scenarios. In this framework, we introduce the development of a Computational Fluid Dynamics (CFD) code designed for high-pressure compressible multi-phase flows. This code, developed within the OpenFOAM framework, is named SoLOCATH-FOAM (Solver for Loss Of Coolant Accident Thermal-hydraulics). The solver utilizes the Volume of Fluid (VoF) technique for dealing with the interface between non-mixing liquid/gas phases. It takes into account variations in the density of liquids using a barotropic equation, which is dependent on the elastic modulus. Presently, the dynamics of the gaseous phase are modeled according to the ideal gas law. SoLOCATH has undergone initial validation through simplified shock tubes and LM-hammer pressure transient scenarios, considering the interactions between a non-reactive pressurized fluid, such as helium, and PbLi. The simulations of those 1-D prototypical problems have provided promising results. Consequently, more complex 2-D and 3-D layouts, which are representative of the breeding zone and its thermo-hydraulic conditions, are being studied to enable the detailed observation of fundamental phenomena in a LOCA-like configuration