Aeroelastic Adjoint-Based Optimisation of Highly Flexible Aircraft Wing Configuration

Summary

This paper investigates benefits resulting from the use of coupled aeroelastic analysis for aerodynamic shape optimisation of a highly flexible wing. The study is carried out on the eXternal Research Forum model (XRF-1) specified by Airbus Commercial Aircraft, representative of a long-range aircraft configuration. Improvements delivered by considering aeroelastic effects for the evaluation of both the aerodynamic performance and the associated gradients are assessed with respect to the results obtained by freezing the wing flexibility in both primal and adjoint computations. An analysis of the impact on the different drag components is also illustrated based on the far-field drag breakdown. Results show that for induced drag, engaging flexibility only at the primal level still allows to capture first-order gain on the final performance. However, engaging coupled-adjoint sensitivities is key to completely master wave drag reduction on the considered highly flexible wing. Performance improvement obtained by increasing the number of design parameters is also investigated.