A Parallel Multi-Domain Solution Methodology Applied to Nonlinear Thermal Transport Problems in Nuclear Fuel Pins

摘要

This paper describes an efficient and nonlinearly consistent parallelsolution methodology for solving coupled nonlinear thermal transport problemsthat occur in nuclear reactor applications over hundreds of individual 3Dphysical subdomains. Efficiency is obtained by leveraging knowledge of thephysical domains, the physics on individual domains, and the couplings betweenthem for preconditioning within a Jacobian Free Newton Krylov method. Detailsof the computational infrastructure that enabled this work, namely the opensource Advanced Multi-Physics (AMP) package developed by the authors isdescribed. Details of verification and validation experiments, and parallelperformance analysis in weak and strong scaling studies demonstrating theachieved efficiency of the algorithm are presented. Furthermore, numericalexperiments demonstrate that the preconditioner developed is independent of thenumber of fuel subdomains in a fuel rod, which is particularly important whensimulating different types of fuel rods. Finally, we demonstrate the power ofthe coupling methodology by considering problems with couplings between surfaceand volume physics and coupling of nonlinear thermal transport in fuel rods toan external radiation transport code.