Multi-scale coupling of CFD code and sub-channel code based on a generic coupling architecture

This paper describes a multi-scale thermal-hydraulic coupling system, which combines the capabilities of the open-source TrioCFD code and of the sub-channel code SubChanFlow (SCF) aiming to improve the description and prediction of the multi-scale thermal-hydraulic physical phenomenon inside the reactor vessel. This is a parallel coupling system based on the ICoCo (Interface for Code Coupling) concept, where each code is first wrapped by the ICoCo interface and then it is compiled to a shared library. A parallel C++ script was developed as the supervisor, which utilizes the two shared libraries and supervises the calculation of the coupled system. The MEDCoupling libraries developed by CEA provide a generic way to handle the mesh interpolation and field mapping between different domains of TrioCFD and SCF. Moreover, the explicit temporal coupling method and the domain-decomposition approach are adopted and presented in this paper. An academic problem is developed to test the multi-scale coupling code. The results indicate that the inter-code data exchange works well and that the coupled code TrioCFD/SCF can deal with various time-dependent boundary conditions.(C) 2020 Elsevier Ltd. All rights reserved.