CFD Modelling as an Integrated Part of Multi-Level Simulation of Process Plants – Semantic Modelling Approach

1. CFD Modelling as an Integrated Part of Multi-Level Simulation of Process Plants – Semantic Modelling Approach Marek Gayer, Juha Kortelainen and Tommi Karhelawww.marekgayer.com www.simantic.orgTechnical Research Centre of Finland (VTT), Espoo www.vtt.fi 42th Summer Computer Simulation Conference, Ottawa, Canada, 11. – 15. July, 2010.

2. Presentation outline - What we are using and doing? • We are developing process simulators software (for e.g. plants) • We are using “semantic” based software tools for that • We have a software platform for easy building and connecting such and other simulation applications • We are building a 3D CFD simulation environment for this platform • We want to optimally connect 1D process and 3D CFD simulations • Our CFD software includes pre/post processing - defining geometry, meshing, boundary conditions, solver, visualization, of the modeled case • We are using open source technologies for that • We are using OpenFOAM in the 3D CFD environment and plan to use and integrate also other solvers, including commercial

3. Dynamic process simulation tools are used for example in: • Nuclear energy sector for planning • Operator support and training • Operation state analysis • Automation design and testing • Safety analysis, and verifications the power plant lifecycle. • The advantages gained using these tools and methods can result in significant time and money savings, and improved safety.

4. Demystifying “semantic modelling approach” and Semantic graph • Defining semantics ~ Adding “meaning” of data objects by specifying their relations and by annotating them using statements. • Based on ontologies (basically “objects and relations between them” model, see: http://en.wikipedia.org/wiki/Ontology_(information_science) • Data consists of resources, statements (forming triplets) and literals. • Resource: a node of the graph. A resource has a unique identity. • Statement: an edge of the graph. A statement consists of three resources: subject, predicate (relation), object. • Literal: any binary data attached to a resource.

5. APROS 6 – Process simulator based on Simantics

6. Example – Ontology based simulation model configuration in APROS 6 Different modelling and simulation approaches are modelled as ontologies and mapped together to form a consistent graph of model configurations.

7. Simantics based Modelica version - modeling language for component-oriented modeling of complex systems

8. Example – model configuration ontologies in Modelica

9. Simantics Ontology Development application

10. Semantic modelling in simulation • Using few concepts and building blocks, we can describe • Control and storage of simulation model and experiments configuration data and tasks • Used data structures, flows and it’s relations • Annotations for real-time gained results • Higher level semantic language abstractions (Layer 0, APROS, Modelica) • Extendibility – all data described by the same simple model • Using semantics in process simulations is quite a new concept • Building software applications based on platform “Simantics”

11. Plug-in Elmer FEM-based multi-physics simulation environment Plug-in OpenFOAM based3D CFD simulation environment  Plug-in APROS simulation engine  Plug-in NuSMV Model checking environment Plug-in BALAS simulation engine  Plug-in PhaseField solidification modelling Simantics Platform • Eclipse based application framework • 2D diagram framework • OpenCASCADE 3D geometry kernel • VTK post-processing and visualisation tools • … • Editors (text, 2D diagram, 3D geometry) • Structural data handling and mapping • Project/team management tools • Distributed modelling and simulation facilities • … Plug-in VTT-Talo building simulation environment  Plug-in System dynamics environment Plug-in OpenModelica system simulation environment  Plug-in ??? Plug-in Architecture for Modelling and Simulation Simantics Core Triplestore modelling database management Simantics Databoard Simulation results and real time data management For more information, visit: www.simantics.org

12. Linking 1D process simulation and 3D CFD • Mapping of the mass and heat flow variables between the models • At in/outflow boundaries, reduce the flow variables of the 3D to 1D • Numerical stability - important issue • Necessary to establish appropriate interfaces and standards • CFD modelling environment with pre-processing, post-processing, solver OpenFOAM, visualization

13. CFD modelling overview of our software prototype

14. Our CFD environment based on OpenFOAM

15. Pre-processing - Geometry • OpenCASCADE for importing CAD models (STEP, IGES, BREP) • Using Open CASCADE would also provide interactive geometry editor. In the present version of the environment, this feature is however missing. • Visualization based on VTK

16. Pre-processing - Meshing Currently NETGEN tetrahedron meshing Integrated as command line tool Built as custom executable Some experiences with hexahedron meshes (snappyHexMesh)

17. Using OpenFOAM solver • Integrated as command line tools, which are launched from our environment • Using OpenFOAM 1.5 (SF openfoam-mswin) and 1.6 (BlueCFD) • Currently 2 test experiments • Tank – (compressible, turbulent flow - rhoTurbFoam) • S-pipe – (imcompressible flow - icoFoam) • Currently dictionaries in cases directories are edited separately • We plan to create ontological representation of OpenFOAM cases dictionaries, - based on sample dictionaries bundled with OF • This way ontologies will be presented in the user interface and from which OpenFOAM dictionaries files will be generated

18. Post-processing – Visualization of OpenFOAM results Using VTK Surface plots Mapping of variables 3D cuts Streamlines Iso-surfaces

19. Additional future work includes: • Boundary conditions module, preferably independent on the solver • Using additional solvers, including some commercial • Establish data transfer and interfaces between process simulation models (1D) and 3D CFD link using Ontologies based interface • Higher level ontological representation of simulation configuration (e.g. without specifying too much details) and possible to work with various solvers • FEM tools integration (e.g. for structural analysis) • More simulation cases and more work with OpenFOAM

20. VTT creates business from technology