Title: The Use of Open Source Software for Integrated Design and Analysis Tools
1The Use of Open Source Software forIntegrated
Design and Analysis Tools
Aerospace PDE 2002 NASA-ESA Workshop
Matthias C. Haupt, P. Horst
Institut für Flugzeugbau und Leichtbau Technische
Universität Braunschweig Hermann-Blenk-Strasse
35 D-38108 Braunschweig Germany m.haupt_at_tu-bs.de
2Agenda
- Introduction
- Airplane Design
- Tool Integration
- Applications
- Conclusions / Outlook
3Introduction
- Institut für Flugzeugbau und Leichtbau (IFL)
- Institute for Aircraft Design and Lightweight
Structures - Technical University Braunschweig
- Prof. Dr.-Ing. Peter Horst
- Environment
- Faculty of mechanical engineering
- Member of the Graduate College Interaction of
Fluids and Structures - National and european research projects
- Cooperations with institutes and industry
- Remarks
- We use standards
- We are looking into the STEP/XML direction
- Open Source approach is interesting
- Fields of activity
- Lightweight structures
- Numerical simulation techniques
- Stability, buckling
- Damage tolerance
- Fluid-structure interactions
- Composites, fibre reinforced material
- Material testing
- Component and full scale testing
- Airplane design and optimization
4Airplane Design
- Aim
- Determination of the optimal shape for a defined
transportation task by a multidisciplinary
analysis - classical criteria are the DOC
- Tasks
- Proof of feasibility of the initial configuration
- Optimization of the initial configuration
- Assessment of changes of the transportation task
- Estimation of the effects of new technologies
- Comparison with alternative configurations at the
same analysis precision
5Airplane Design
6Airplane Design
7Airplane Design
- Challenges
- Identification and analysis of problems already
in concept phase - Early simulation of critical difficulties of the
actual airplane design with visualization - Emergency evacuation
- Dynamic behaviour of the structure / crash
- Retraction of the landing gear
- Flightdynamic simulation of critical flight
manouvers - Consideration of further nonclassical aspect of
market success - Cabin design acceptance of the passengers
- Ground services (use of standard service
vehicles, minimal grounding times) - Compatability with the infrastructure of the
airports
8Airplane Design
- Difficulties of the computer aided airplane
design - High complexity of the entire problem with
extensive data - Different self developed and commercial modelling
and analysis tools - Intensive data transfer between tools with
diverse interface standards - Transition from simple to complex modelling and
analysis tools - Manual execution of the workflow is time
consuming and error-prone - Need for a flexible tool integration
- Users are students, engineers and scientists
(acceptance) - Different projects ( duration 0.3 - 6 years )
- Numerous of inhouse and commercial tools
- Easy to learn, to handle and to understand
- ... at low costs ... for a long period
- ... different levels of complexity
- ... reuse of existing code
... teaching the techniques
9Airplane Design
Tool Integration
- State of the IFL tools today
High Fidelity Simulation
PrADO
Preprocessor A
PrADO-DB
Module A
Analysiscode A
DB1
Module B
Preprocessor B
DB2
Analysiscode B
Module C
DB3
Module D
Project Analysis Environment
Analysiscode X
Preliminary Aicraft Design
Project partner B
Project partner A
10Airplane Design
Tool Integration
- ... the next step with STEP (?)
- Better exchange of data
- and methods !!!
PrADO
Preprocessor A
Datamanagement STEP / XML (?)
Module A
Analysiscode A
Module B
Preprocessor B
Analysiscode B
Module C
Module D
Analysiscode X
Integration Environment
Project partner B
Project partner A
11Airplane Design
- Objectives of our development
- Automation and integration of the workflow
- Flexible data transfer between tools
- Integration of different source codes as well as
executables - Simplicity, clearness, flexibility and robustness
of the integration approach - Efficient rapid prototyping for new (sub-)tasks
- Interoperability with project partners
- We develop methods to solve our engineering
problems - Use of available technologies, standards and
tools -
- . . . suitable Open Source Software
- perhaps a special kind of standard
12Tool Integration
Basic components of the integration approach
- Python
- Object-orientiented scripting language contains
elements of traditional languages - Nice, simple syntax
- Modular structure
- A lot of books
- Unix, Windows, ... very stable
- Scientific computing
- Standard packages of Python
- Tkinter Widgets from Tk for GUI's
- Numerical Vector / matrix objects
- Scientific Python
- Scientific tools, MPI, NetCDF, ...
- Visualization Tool Kit vtk
- 3D computer graphic system,
- defines the architecture
- compiled kernel C
- Wrapper for Tcl, Java and Python
- Render windows, renderers, actors,
- properties, lights, cameras
- Data objects (general, grid data),
- Process objects (source, filter, mapper)
- Reference books and examples
- OpenGL ... WinTel, Unix
- I/O for VRML, IGES, 3DS, HDF,
- Interface generators
- pyfort Fortran
- swig C, C
13Tool Integration
Visualization pipeline of vtk
Reader SourceObject() DataObj1
Reader.GetOutput() Filter ProcessObject() Filter
.SetInput( DataObj1 ) DataObj2
Filter.GetOutput() DataObj2.Update()
SourceObject
- Data Objects
- represent information
- Methods to create, access and delete this
information - Methods to obtain characteristic features
- STEP-Objects (?)
- Process Objects
- operates on input data to generate output data
- Sources interface to external data (Reader) or
generate data from local parameters - Filter require one or more input data objects and
generate one or more output data objects - Mapper objects are used to convert data into
graphical primitives
DataObj1
ProcessObject
DataObj2
- Pipeline Execution
- causes process objects to operate
- Implicit control implemented demand-driven
- Process object execution if input change
- Two-pass process update and execution
14Tool Integration
- Integration environment ifls
- Extension modules
- utk connects vtk and pure Python objects to
maintain pipeline mechanisms - usr extents the cababilities of the vtk-process
objects - dtn with special data and process objects for
geometry and grid generation based on DTNURBS
(IGES) and GridLib - stk with process and import/export objects for
analysis and simulation in a distributed
environment - (Structure Ansys, MSC, Abaqus, Fluid HISSS,
Flower, Cavecats, Tau) - Graphical editor
- Interactive manipulation and visual programming
- Analyses the programmed object interactions/networ
ks - Visualize the object interactions ( tree / graph
) - Coding conventions for the automatic generation
of the networks, object editors and documentation
(html, latex, postscript, pdf). - Python codes are executable without the graphical
editor in batch mode, because the GUI is an
optional feature.
15Tool Integration Graphical User
Interface
Pipeline
Object Editor
Object Documentation
16Application
Oblique Flying Wing
- Geometry
- wing, fin, wake
- .db (PrADO)
- Grid
- .msh (HISSS)
- Results
- .sca (HISSS)
- .plt (Tecplot)
- Aerodynamic Loads
- Derivatives
- Optimisation
- Interactive variations
- Students project
17Application
Aeroelasticity
- Mapping between different surface-grids
- State-/Flux-transfer by
- Domain- Decomposition approach
- Reference geometry
- Deflection transfer by vtkThinPlateSplineTransform
18Application
Aeroelasticity
- Reference geometry
- Euler code
- MSC/Nastran
- Coupling iteration
- for the
- equilibrium state
- Deflection transfer by vtkProbeFilter and
self-developed hybride techniques
19Application
Aeroelasticity
- A340 Wing
- Incomplete FEM model
20Application
Airport Environment
- Visualization of the design parameters of a new
configuration
- Geometry
- Simulation results
21Application
Airport Environment
- Simulation of vehicle motions in the airport
environment (compatibility)
- Different dynamic models
- Ground service simulation with MissionLab
22Application
Airport Environment
- Flight dynamic simulation with JSBSim from the
FlightGear-Project
- Complete set of the equation of motion including
ground forces and FCS - XML-formatted description of
- Servoelasticity
- Geometry
- Massprops
- Aerodynamics
- LandingGear
- Propulsion
- Initial state
23Application
Fluid-Structure-Interaction
- ASTRA/IMENS Project - Coupled
thermal-mechanical analysis
Mach Number
- Flap-gap model
- Reenrtry X38 / CRV
- Navier-Stokes-Code
- coupled with
- FEM-Code
- Comparison with wind tunnel experiments
Stanton Number
Structural Temperature
24Application
Fluid-Structure-Interaction
Fluid Reader (NetCDF)
Structure Reader (.bdf)
Iteration Control
Heatflux Transfer
Heatflux-Writer (.bdf) CS-Analysis
(Nastran) Temperature-Reader (OP2)
Temperature Transfer
Heatflux on the coupling surface
Temperature-Writer (NetCDF) CFD-Analysis
(Tau-Code) Heatflux-Reader (NetCDF)
25Application
- ASTRA/IMENS Project
- Research project of 5 DLR institutes and the IFL
(responsible for coupling techniques) - Goals
- Simulation of thermal-mechanical fluid-structure
interactions of hypersonic applications and the
experimental validation - Timeaccuracy with respect to thermal behaviour of
the structure (2001-2003) - Coupling of the codes Tau (DLR), DavisVol
(Astrium) and MSC/Nastran, Ansys - Validation by wind tunnel experiments
- Use of the MpCCI Standardlibrary for direct
code coupling via MPI sourcecode availability
necessary otherwise file oriented data exchange - Tent workflow management system (DLR) enables
distributed / grid computing (CORBA) and access
on a LDAP-server for documents - Simple problems
- geometric nonconform models (grids exist)
- structural modelling (radiation)
- ...
26Concluding remarks
Outlook
- Concluding remarks
- Open Source approach of ifls is successful at the
IFL . . . and makes fun - Finding and evaluation of Open Source Software is
not easy - Analysis codes are not considered here
- Need for data standards and tools
- Interactive examples ... please contact me
- Outlook w.r. Open Source
- ActionFactory (JULIUS-Project)
- for CORBA connectivity
- OpenCASCADE for geometric modelling (IGES/STEP),
Python bindings in work - Simulation environment Salome (not Open Source up
to now) - ... uses Python and vtk as well
- PDM environment PGPDM