Emerging Technologies for FETCH2

1. Emerging Technologies for FETCH2 Jeff Gomes Applied Modelling and Computation Group (AMCG) Severe Accident Subproject Meeting 14/11/2011

2. Outline • Multi-Physics Software Suite; • Next-Generation Multiphase Flow Dynamic core (synergy between projects within AMCG); • Emerging Multi-Physics Technologies.

3. AMCG: Multi-Physics Software Suite Multi-Physics Models Legacy • Add an adaptivity library which performs topological operations on the mesh, and mesh movement, to optimise the size and shape of elements in response to error measures • Working robustly and efficiently in parallel • Also building an adjoint to the model for data assimilation, sensitivity studies and goal-based error estimation • Make use of open source solutions for solvers, preconditioners, I/O, visualisation, etc • Fissile solutions, porous media matrix, reactors; • Compressible (with phase change) and incompressible flows; • Simple structural mechanics response (i.e., limited stress failure criteria); • Quad/Hex finite elements with CV representation of scalar fields (no parallel adaptivity); • Finite/Discrete Element Methods; • Particle modelling (Newton Law) and structural mechanics (material engineering – stress modelling); • One-/Two-Way coupling with Fluidity; • Used in coastal defence, reservoir fractures and particle flows applications; • But can be potentially used in nuclear engineering (geological waste repository and stress-induced core fractures and degradation in reactors) Fluidity-ICOM (CFD, single phase, multi-material) Fluidity (Multiphase) Fluidity-Multiphase (CMFD) FETCH (coupled Multiphase and RT) FETCH-2 (couples multiphase, RT and structural response) VGeST (DEM, FEMDEM) EVENT (Radiation Transpot) Radiant (RT)

4. AMCG: Multi-Physics Software Suite

5. Research & Development: Emerging Technologies (Improving Modelling Functionality)

6. R&D (Cross-Cutting activities), 2010-2014 FETCH2 FETCH2 FP7/THINS: Discretisation Methods FP7/GoFastR & EPSRC-SA: Safety Assessment in reactors (severe accident scenarios) AMCG New Dynamic Core for multiphase flow in Fluidity EPSRC-MBase/B&W: Criticality in Fissile Solutions Qatar Petroleum/Shell New Model for Reservoir Simulator

7. Emerging Technologies: Mesh Adaptivity and Domain Decomposition Lower frame shows the domain decomposition which has been optimised to balance the load based on number of nodes and minimised edge cut

8. Emerging Technologies: Mesh Adaptivity and Domain Decomposition – lock-exchange problem (P1DGP2 balance element) Movie

9. Emerging Technologies: Multi-Material Interface Tracking (moving and adaptative meshes) • Compressible high-resolution control volume advection methods combined with moving and adaptive meshes; • Limiting schemes to ensure conservative and bounded solutions; • Arbitrary number of materials can be tracked.

10. Emerging Technologies: Multi-Material Interface Tracking (3 materials)

11. Emerging Technologies: Conservative interpolation – crucial for many applications with mesh adaptivity and coupled models ‘donor’ mesh ‘target’ mesh ‘super mesh’ and mapping from donor mesh Following construction of the supermesh we are able to perform projection operations to achieve conservative, bounded (etc…) interpolation schemes. 2D: Farrell et al., 2009 3D: Farrell, Maddison, 2009

12. Emerging Technologies: Finite/Discrete Element Methods (FEMDEM) FEM + DEM

13. Emerging Technologies: Finite/Discrete Element Methods (FEMDEM) • Land-slide and • Idealised coastal defence

14. Emerging Technologies: Finite/Discrete Element Methods (FEMDEM) • Idealised coastal defence accropode blocks; • Study of stress-induced fractures for different block designs.

15. One-/Two-way coupling of Fluids and Solids (Capturing Interactions) In Fluidity, solid is treated as fluid (multiphase flow) 1 mesh for the domain (fluid), 1 mesh for solid: user-friendly as it is easy to generate the meshes of complex solids Usage of Conservative Interpolation in order to obtain solid's location on the fluids mesh Exchange of momentum and location between solids and fluid at each time-step Introducing third phase: Air (acting as a surface) Emerging Technologies: Immersed-Body Method (Fluid-Solid Interaction Modelling)

16. Emerging Technologies: Immersed-Body Method (Fluid-Solid Interaction Modelling)

17. Immersed-Body Method Re=5k Re=1k

18. Emerging Technologies: Immersed-Body Method (Fluid-Solid Interaction Modelling)

19. Emerging Technologies: Thermo-Chemical Modelling • Initial generic chemical modelling framework for geochemistry application (funded by QCCRSC Programme) for oil/gas reservoirs, CO2 sequestration and storage aquifers (PhD student); • Chemical kinetics and thermodynamic equilibrium; • In order to improve of our understanding of a set of SA phenomenology we need a sophisticated thermo-chemical model framework within (or coupled to) FETCH2 with a reliable chemical-kinetics library covering: • Chemical reactions and advanced thermodynamics (EOS  phase change);

20. Back-up Slides

21. Research & Development Model and Software Quality Assurance • Code repository; • Automatic and continuous verification & validation; • More than 100 verification & validation test-cases for RT; • More than 1000 verification & validation test-cases for CFD (including unit-tests); • Large number of benchmark tests for the coupled formulation (e.g., TRACY, SILENE, CRAC, SUPO, HTR, Shipping-port reactor and other AIEA –based tests) • Full documentation; • International training (e.g., B&W, LANL, Y12, open-source community, etc)

22. Research & Development Model and Software Quality Assurance