Development of a Rapid Turnaround Modeling Ability for PbLi Blanket Module

HIMAG, an advanced MHD modeling tool that was developed to simulate flows in liquid blankets, could have application to the design and development of the Test Blanket Module (TBM) for ITER, a fusion energy facility. HIMAG is a multiphysics-based solver that addresses various aspects of TBM-like flows, including high Hartmann number MHD modeling in complex geometries, heat transfer, and tritium transport. It also can model multi-material domains, free surface flows, and the coupling between fluid flow and heat and mass transfer. This project will develop a strategy to transition HIMAG into a high performance workhorse for the ITER TBM. This strategy involves the application of: (1) novel mathematical convergence acceleration techniques, (2) rapid prototyping capabilities to accelerate problem setup, and (3) variable fidelity modeling, to provide better initial conditions and MHD-specific convergence acceleration procedures. Phase I will involve the development of a multigrid method for Poisson solvers; a fully-implicit, Jacobian Free Newton-Krylov scheme for overall solution acceleration; and a semi-analytical treatment of Hartmann layers, including generalized wall functions to avoid stringent mesh space requirements. The experience gained from implementing these features will provide the rationale for a larger scale effort in Phase II. Commercial Applications and other Benefits as described by the awardee: The field of liquid metal MHD at high Hartmann numbers suffers from a lack of general-purpose computational tools needed to satisfy the current needs of fusion designers working on blanket designs for testing in ITER. The improved HIMAG tool should find use in both closed channel and free surface flows, and in buoyancy-driven flows, for metullargical and energy generation/management applications.