CPACS - Common Parametric Aircraft Configuration Schema Daniel Böhnke Air Transportation Systems German Aerospace Center, (DLR)

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Integrated Aircraft Design Requirements, Targets Optimization Parameterization Analysis 1 Database CPACS Database Analysis 1 Meta-Modeling Iteration Analysis 2 Analysis 2 Analysis n Performance, Properties Analysis n Sensitivities Distributed system Tools of specialists are wrapped Coupling via central data model CPACS software.dlr.de

Central Model Architecture Lifting Line Panel code Functional Parametrization Euler CPACS Different models with different geometric representations can be derived from the global CPACS model using the software libraries. software.dlr.de

Common Namespace Reduce No. of interfaces Standardize ► n(n-1) Product and process information Human readable ► n(n-1) ► 2n software.dlr.de

Holism ? Exchange relevant information Intersections of disciplines Exchange relevant meta-information Dynamic or static ? Start with the Requirements Again we will focus on some key aspects Only picked the most important requirements Task 1: Identify relevant information that must be exchanged Aerodynamic guy is only interested in wing bending Structure guy is interested in pressure distribution This is a standard two discipline problem, multidisciplinary projects tend to connect partners that do not know about their interaction Task 2: If information is exchanged it must be transperent. Meta information should be exchanged as well, you need to know if another discipline has an influence on you model. This can either be: Static: Mark elements in the model that might be affected Dynamic: Observe the model and highlight toool interaction with the model. A tool may react dynamically to a model from: Dream Airplanes, C.W. Miller software.dlr.de

Accessibility Information is always converted Interaction of discipline and modeling experts One of the key factors! Who exchanges information in the central model, who is responible for the interfaces? There are two kinds of engineers involved: Single Domain Experts, Modeling Experts Single Domain Experts can benefit from dynamic boundary conditions for his calculations as well as parametric description of his models Modeling Experts are interested defining common definition for the system, in this respect the aircraft Design Expert must connect his tool to the model known by the modeling expert, usually conversions, changes of programming languages and ambigouity occur. Example implicit geometry information. Library must be available to read the data to make sure data is valid from: Dream Airplanes, C.W. Miller software.dlr.de

Re-usability {…} Automatic model generation Reduce erroneous Design Loop Automatic model generation Reduce erroneous Generation of derivatives There is not much sense in setting up a central model and then generate it by hand Many parts of the model may be generated by analysis tools, but a startup solution is eminently important As people are setting up parts of the model in disciplines they are no experts for, sources for errors occur easily from: Dream Airplanes, C.W. Miller software.dlr.de

Abstraction Methods Classification Association Generalization Distinguish between content and metamodel Partial-hierarchical models Complex mechanisms hamper comprehension Structure in Modeling Languages is generated by Abstraction Methods. These are usually similar to those that can be found in object oriented programming. Important features to name are Classification, Generalization and Association It is important to always distinguish between the syntax defined in the meta model and the explicit semantically interpretable content model All of the models in this work are partial-hierarchical system descriptions As always simpler systems are desired. Don‘t overdo it software.dlr.de

Common Parametric Aircraft Configuration Schema MDO aircraft design Distributed simulation Collaborative development software.dlr.de

CPACS DLR intern standard based on XML / XSD development in ~2005 specific libraries Applications in DLR Projects: Aircraft design Helicopter design Engine design Climate impact software.dlr.de

TIXI – XML Interface Handle CPACS Basic XML functions Advanced CPACS functions Arrays Unique Identifiers … software.dlr.de

TIGL – Geometry Library Visualization Calculation Area Intersections Inner <> Outer Export STL IGES software.dlr.de

RCE - Remote Computing Environment Framework Integrated Capabilities Distributed software.dlr.de

References T. Zill, D. Böhnke, B. Nagel, V. Gollnick, Preliminary Aircraft Design in a Collaborative Multidisciplinary Design Environment, AIAA Aviation Technology, Integration and Operations Conference, 2011 D. Böhnke, B. Nagel, V. Gollnick, An Approach to Multi-Fidelity in Conceptual Aircraft Design in Distributed Design Environments, IEEE Aerospace Conference, 2011 D. Böhnke, M. Litz, B. Nagel, S. Rudolph, Evaluation of Modeling Languages for Preliminary Airplane Design in Multidisciplinary Design Environments, DGLR Congress, 2010 C. Liersch, M. Hepperle, A Unified Approach for Multidisciplinary Aircraft Design, CEAS European Air and Space Conference, 2009 A. Koch, B. Nagel, V. Gollnick, K. Dahlmann, V. Grewe, B. Kärcher, U. Schumann, Integrated analysis and design environment for a climate compatible air transport system, AIAA Aviation Technology, Integration and Operations Conference, 2009 software.dlr.de

„All models are wrong, but some are useful.“ George E.P. Box software.dlr.de

Collaborating DLR Institutes AE Aeroelasticity www.dlr.de/ae/en AS Aerodynamics and Flow Technology www.dlr.de/as/en AT Propulsion Technology www.dlr.de/at/en BK Structures and Design www.dlr.de/bk/en FA Composite Structures and Adaptive Systems www.dlr.de/fa/en FL Flight Guidance www.dlr.de/fl/en FT Flight Systems www.dlr.de/ft/en FW Air Transport and Airport Research www.dlr.de/fw/en HR Microwaves and Radar www.dlr.de/hr/en LY Air Transportation Systems www.dlr.de/ly/en ME Aerospace Medicine www.dlr.de/me/en MF Remote Sensing Technology www.dlr.de/caf/en PA Atmospheric Physics www.dlr.de/pa/en RM Robotics and Mechatronics www.dlr.de/rm/en RY Space Systems www.dlr.de/irs/en SC Simulation and Software Technology www.dlr.de/sc/en software.dlr.de