Transition From Preliminary to Detailed Design of a Highly Elastic Solar Electric Aircraft

Abstract

This work presents the evolution of the aeroelastic modeling of a solar electric aircraft. The dimensions (wing span of ≈27.0 m) and the extreme light-weight construction (wing loading ≈4.0 kg/m²) results in a highly flexible aircraft, making aeroelastic analyses mandatory in all stages of the aircraft design. Comparing the preliminary with the detailed design phase, the aeroelastic models are significantly improved in their level of detail. Still, the models show similar structural dynamic characteristics and a comparable loading, e.g. in terms of wing bending and torsional moments and , where the highest loads are caused by similar load cases. For the sizing, the analytic approach from the preliminary design is backed-up with numerical analyses using a detailed FE model. A comprehensive flutter analysis confirms the findings obtained from a flutter check during the preliminary design. Finally, first structural tests are prepared to validate the models.