#### Parametric geometry modeling as a basis for multidisciplinary optimization in aircraft design.

Today more than ever, the design of new aircraft models is a costly and time-intensive process due to the high demands. Starting with a mission profile (payload, range, fuel consumption, etc.), the design process goes through the phases of conceptual design, preliminary design and detailed design. In each of these phases, the requirements of different disciplines, such as aerodynamics, structural mechanics, flight physics or fabrication, need to be optimized in regard to their interactions so that the new aircraft model meets all requirements.

Until recent years, the calculations of the individual disciplines were carried out independently, so that, for example, the impact of the calculation results of an aerodynamic calculation had to be entered manually into the input model for subsequent structural mechanics calculation. Moreover, changes in the aircraft geometry had to be transferred manually into the respective models of the individual disciplines.

By integrating multiple disciplines into an optimization tool that automatically transmits the impact of the calculation results of one discipline into the input model of another discipline, the development process can be accelerated and an optimized result can be achieved in a shorter time. All discipline-specific input models are based on the aircraft geometry, which means that it forms the basis for the coupling of the calculations from the different disciplines.

In order to implement this project, Airbus Defence and Space participated in the joint project AeroStruct, which is coordinated by the German Aerospace Centre (DLR).

In this context, RISC Software GmbH was given the task of designing a software system that brings together the existing analysis programs of Airbus Defence and Space in order to achieve a synchronous progress of the individual disciplines.

- Selection of an existing standardized description language for aircraft geometries
- Definition of a parametric geometry model for aircraft based on the description language
- Development of a tool for creating geometry from the description language
- Geometry creation of internal wing structures (ribs and spars)
- Intersection of the wing geometry with the geometry of the internal structures
- Creating a GUI application for the manipulation of the parametric geometry model
- Development and integration of a data format of the aircraft geometry model including discipline-specific data based on HDF5
- Definition of design variables and mapping to parameters of the model geometry