Manufacturing, Assembly and Integration of a Large Scale Composite Wing Wind Tunnel Model and the Design and Implementation of an associated Measurement System

Abstract

Building a wind tunnel model with an innovative aerodynamic design including a laminar airfoil concept and morphing parts requires a suitable manufacturing and assembly plan to transfer the virtual model to concrete reality.The contribution of the INVENT GmbH within the GRETEL consortium is the manufacturing of the main structural components of the Wing and the integration of the Wind Tunnel Model. To realize such a precise projection, the main approach is to implement a high overall accuracy of the later model by realizing a low percentage of geometry deviation already on piece part level. Beginning with a material dedicated tool design concerning cure cycle parameters and induced strain effects, for aspects of geometrical manufacturing accuracy, also suitable inspection techniques, regarding the verification of structural requirements and material conditions are implemented in the integration process at specified steps.A further part of the integration process of the GRETEL Wind Tunnel Model is the installation of application-related measurement equipment. The Institute of Composite Structures and Adaptive Systems of the German Aerospace Center (DLR) is responsible for the design and realization of such a project customized measurement concept. For the measurement of the pressure distribution along the profile contour with various angles of attack and wing configurations during the testing, the wing is equipped with several pressure taps. Further, the measurement equipment spectrum covers also the registration of acceleration forces and mechanical loads of the inner wing structure components. This concept creates a holistic picture of the coherences between aerodynamical and mechanical dimensions for each tested configuration.The implementation of all aforementioned aspects into the large-scale model is elucidated and discussed in the light of morphing parts of the model being delivered by another project. The integrated equipment is described and the impact of the integration into the design and assembly of the overall model is illustrated.