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Parametric Fuselage Geometry Generation and Aerodynamic Performance Prediction in Preliminary Rotorcraft Design

The creation of an integrated rotorcraft conceptual and preliminary design framework at DLR involved the development of geometry and fuselage aerodynamics modules at the Institute of Aerodynamics and Flow Technology. After a short revision of the RIDE rotorcraft design environment architecture this paper focuses on the implementation of these disciplinary modules. The aim of the geometry module is to bridge the gap between conceptual and preliminary design and to allow for geometry parameter and optimization studies in the preliminary design phase. An overview of geometry generation concepts is given. Then the selected and implemented template-based geometry generation process based on the commercial CAD system CATIA and its integration into the design framework are described. Furthermore the underlying component catalog concept is illustrated considering the example of basic templates for the generation of rotorcraft geometry components. The fuselage aerodynamics module presented in this paper is based on the commercial panel code VSAERO combined with a simple estimation for pressure drag due to separated flow. The aerodynamics module is applied to common testcases and compared to experimental results. Finally, the usage of the newly developed modules within the preliminary design framework is demonstrated by coupling them in a toolchain, showing the effect of geometric parameters on the predicted aerodynamic performance of the fuselage.