1. Modeling the blanket module: Multiphysical computations and rapid turnaround capabilities Ramakanth Munipalli, C.M.Rowell, K.-Y. Szema, P.-Y.Huang HyPerComp Inc., 2629 Townsgate Rd., #105, Westlake Village, CA 91361 Alice Ying, Neil Morley, Mohamed Abdou, Sergey Smolentsev, Manmeet Narula UCLA FNST Meeting, UCLA, August 14, 2008

2. Objective: To create a simulation management software with integrated prediction capability for blanket modules (extendable to the divertor and other PFCs) operating in a fusion environment Phase-I SBIR: CAD-Centric Management System for a virtual blanket module Period of performance: July 2008 – March 2009 Conventional modeling involves using various codes to individually model physics This is a CAD-centric multiphysical software integration project – no new physical modeling ability is sought in individual disciplines

3. Outline  Scope of the VTBM project  A description of the functionality and uniqueness of the VTBM environment  Some details on implementation  Phase-I tasks

4. Blanket Module: Location and attributes

5. Blanket Module: Details and flow features Key Physical Phenomena: Fluid flow, MHD (we will focus on liquid breeder) Heat transfer Structural mechanics Neutronics Tritium transport

6. Inputs: Blanket geometry including front and return ducts: Toroidal width, radial depth, poloidal height, FCI dimensions, gap thickness Helium duct dimensions Inlet manifold geometry Surface Heating (function of poloidal coordinate) Volumetric heating as a function of (r,p) coordinates Temperature distribution in cooling He channels Heat transfer coefficient in He flows Thermophysical properties of PbLi, He, Fe, SiC Inlet/Outflow Delta T in PbLi and in He Inlet PbLi velocity for each duct Magnetic field distribution Outputs: Velocity field in the bulk flow and in all sections of the gap MHD pressure drop Temperature distribution in PbLi, ferritic structure and FCI Temperature drop across the FCI Interface temperature between FCI and PbLi Calculated inlet/outflow temperature in PbLi for each duct Heat losses from PbLi into He flows Structural deformation Tritium concentration Typical Input and Output data

7. VTBM: A description based on functionality Major VTBM attributes:  Project management – manage the entire simulation process from one convenient interface  Assistance in problem setup across multiple software platforms  Time and Space coupling – “loosely” or “tightly” coupled simulation process  Intelligent problem setup, maintain I/O schedules for each solver  Conservative and accurate interpolation techniques – Fast octree approaches  CAD-based data transfer: Redo CAD when geometry deforms  Visualization of results

8. AML (Technosoft Inc.): Adaptive Modeling Language. Product, process development cycle integration, multidisciplinary modeling. Knowledge based engineering (KBE) framework that captures knowledge from the modeled domain and creates parametric models. ISIGHT (Engineous Software): Rapid integration of commercial and in-house simulation programs. Automates code executions. Optimization, design of experiments, quality engineering, visualization. ModelCenter (Phoenix Integration): Visual environment for process integration. “Adaptable”. Design, archive, update the design process all in a visual environment. Process Data Management (PDM) tools help store information about process and design data. ANSYS Multiphysics: The capability is available. However, the basic survey shows that the usage in industry is virtually non- existant. MDOPT (Boeing): CORBA based interdomain communication facility creates workflow criteria for multiphysical coupling and optimization. Some commercial MDA implementations

9. User concerns  “Every business needs a great deal of customization”  “How does one troubleshoot a multiphysical solution: Who is the culprit?”  “I would like to be able to go under the hood and perform diagnostics. The dash-board type control is insufficient”  “Existing commercial Multi Disciplinary Analysis (MDA) environments require a lot of customization before they can be integrated into a development cycle”  “A truly adaptable MDA environment does not currently exist”

10.  Physical phenomena encountered are extreme: Strong sensitivity to geometry changes, high EM interaction, large gradients in material properties, intense material interface effects in heat, current and mass transfer, multiscale coupling across physics  Our emphasis will be on the accurate and robust coupling of physics relevant to the fusion environment.  The graphical interfaces, as well as geometry generation and post-processing utilities will be customized to modeling blanket/heat-shield physics  Problem setup, and troubleshooting using an “intelligent” front-end Change in cross sectional velocity profile due to change in SiC conductivity (left – 5 /ohm/m, right – 500 /ohm/m Uniqueness of the VTBM approach

11. Computational analysis tools of interest to VTBM

12. VTBM Work-flow diagram: problem setup

13. VTBM Work-flow diagram: Field solution and postprocessing

14. VTBM: Integrated physics modeling schematic (G)

15. Neutronics Treatment In the phase-I project neutronics data will be assumed to be given, computed from prior studies. We will use one- dimensional distributions of power density as a source term in thermal and flow modeling.

16. Thermal analysis Traditional thermal analysis for non-conducting flows such as Helium and water will be performed using off-the-shelf third part software – motivated by their speed MHD flows with heat transfer and natural convection, including heat transfer in conducting solid walls will be computed using HIMAG. While numerous commercial codes are able to compute flow and heat transfer in complex structures, we will focus on the use of SC/Tetra in Phase-I. Future extensions will include FLUENT and CFdesign. MHD (PbLi) Helium Thermal and electrically conducting wall Radiative heat input

17. 1 / Ha 1 / sqrt(Ha) U(z) j(y,z)  Ha ≈Ha -1 B  // ≈Ha -1/2 2h Hartmann layer Side layer FLOW The exacting needs of numerical MHD

18. Second order convergence for high Hartmann no. flows Benchmarked against expt. data at fusion relevant conditions Complex geometries, non-orthogonal, hybrid meshes, parallel computing HyPerComp Incompressible MHD solver for Arbitrary Geometry

19. Development of an effective user interface - 1 Physics model editor (left), Graphical BC selection (below)

20. Development of an effective user interface - 2 Customization of the view pane based on simulation stage

21. VTBM : Use of CGNS as a common data file format We seek to provide a common base-format to maintain simulation data throughout. CGNS (CFD General Notation System) is a likely candidate. It is open-source, well documented and used by various commercial software already In general, simulation codes use native grid/data formats. e.g.: TEMPUS-G IGES, STEP CAD files, and native TGP format HIMAG UXUnstructured Grid UGMBoundary patches and BC info SC/Tetra PREComputational Mesh including material regions FLDField data, including computational mesh and other physical information ANSYS CDBCommon database format including mesh and field solution

22. nofelmts : Number of FCI channels noftube_l: Number of He channels along width Template-based approach: Geometry parameterization

23. Template-based approach: Geometry creation

24. Template-based approach: Grid generation

25. Helium Ferritic Steel SiC PbLi Pb 17 Li Helium Pb 17 LiPb 17 Li Helium Mesh generation by segregation of geometrical features

26. Interpolation techniques: Point-element relations for standard interpolation Element-element relations based on intersection Point-point relations for matching grids/nearest neighbor E P E1 E2 P Interpolation techniques Octree search procedures CAD based surface data interpolation is being developed

27. MHD mesh Stress analysis mesh CAD Model Two types of data communication: All-to-all: n 2 -n interactions CAD Based: 2n interactions Technical challenge: Conservation of forces, moments, etc. Coupling across physical disciplines

28. VTBM : Data interpolation

29. (a) (b) (c) (d) VTBM : Data interpolation – contd.

30. NURBS (NonUniform Rational B-Spline) procedure for structural deformation CAD Surfaces are represented parametrically with NURBS as: u,v are parameters, W ij are weights, B ip is a B-spline of degree p at control point i P ij are locations of NURBS control points The field solver computes loads, deflections, etc. at discrete points r m These are projected onto the NURBS surfaces and corresponding u m, v m are found (This is done at the grid generation stage itself) If the NURBS expression above is rewritten as: A new NURBS surface is fitted using least squares after deformation, using:

31. VTBM : “Appropriate” visualization of physics 2-D dominant 3-D dominant

32. Customized post-processing: TECPLOT EDGE® Traditional TECPLOT layout TECPLOT layout can be customized to suit the application Integrated TECPLOT for complex visualizations

33.  Dealing with third party software and APIs  Communication issues, resource management  Compliance with industry standards for I/O data  Interaction with the TBM community and timeline for development  Licensing, Documentation and Software dissemination  Using open source modules: CGM (Sandia, Argonne), CGNS (NASA) VTBM – Software Development Issues

34. VTBM – Object Oriented Software Development

35. Phase-I Project Objectives Task-1: TBM model assessment, redefinition of the VTBM concept in light of current developments in neutronics, existing template-based tools and advancements in CAD-coupling. Task-2: Development of a unified data flow system which will enable storage and transfer of simulation data across heterogeneous software relevant to TBM using CGNS and native data. Task-3: Physics-dependent accurate interpolation technique across computational meshes Task-4: Perform essential visualization procedures and plan automation Task-5: Development of a preliminary geometry deformation scheme for CAD/parametric model. Task-6: Verification and validation of the managed simulation technique on test problems. Task-7: Assessment of project needs and scope of a full scale implementation of the VTBM

36. Phase-I Timeline