Computation of two-phase flow in steam generator using Domain Decomposition and Local Zoom methods

Abstract

We present flow simulations in the Steam Generator of a pressurized water nuclear reactor using Domain Decomposition Methods (DDM) and Local Zoom methods on workstation cluster. Concerning the DDM, we use a Dirichlet–Neumann approach jointly with FEM for averaged mixture balance equations. The algorithm, based on parallel or sequential iteration-by-subdomain method, works with overlapping or nonoverlapping subdomains and with conforming or nonconforming meshing. With DDM, the computational problem size is easily increased to about 100,000 mesh cells and the CPU time is strongly reduced. Concerning the Local Zoom computations, the used Local Defect Correction (LDC) method, in 3D local hierarchical multigrid context, is shown. The LDC computation results are compared with the classical full domain computation results (with high or low spatial resolution). We conclude in an improvement of the accuracy on the full domain with a high coherence between the zoom and the full domain.