A Multiscale CFD/1D-TH Coupling Overlapping Domain Methodology for Thermal Hydraulic Systems

摘要

The work presented in this paper describes the development of the overlapping domain (or volume interface) capability of the coupling infrastructure JANUS, between the CFD code STAR-CCM+ and the best-estimate system code TRACE. The overlapping domain coupling methodology was then applied to a closed loop driven by natural circulation. It has been shown that the solution of a system code can be effectively corrected by making use of CFD for selected portion of the overall system to be modeled. The use of CFD only for selected portions of the system to be modeled allows to significantly improve the accuracy of system code solutions, at the same time making effective use of computational resources, with runtimes reduced markedly from CFD standalone cases. The interfacing techniques used in this research also exhibit favorable stability characteristics. Future work includes the application of the JANUS coupling of transients of interest for nuclear power plants, such as LWR ATWS, where 3D models are needed to accurately capture the boron transport to the core. Toward this, an interface between a STAR-CCM+ region and a TRACE VESSEL component is currently under development. This interface will be able to correct TRACE results for flow distributions and pressure gradients within the multi-dimensional interfaced region.