Aeroelastic analysis of distributed electric propulsion flexible wings

ifasd2024 Tracking Number 129

There is much current emphasis on the development of alternative aircraft propulsion technologies to enable much reduced, and eventually, net-zero in-flight commercial aircraft emissions. The success of this goal is not simply dependent upon the advancements in electric or hydrogen-powered propulsion systems, but also on how to integrate them into the aircraft structures. It is likely that distributed electric propulsion (DEP) configurations featuring small engines spaced across the wing will be the most viable solution. However, the adoption of these novel aircraft wing configurations might initiate the early onset of two potential aeroelastic instabilities: wing flutter and whirl flutter, which must be addressed in the early design stages of DEP aircraft wings. The main aim of this study is to create and evaluate a representative low-order aeroelastic coupled wing-propeller model for parametric aeroelastic studies that can be used in the flutter analysis at the early design stages. An aeroelastic numerical model was developed in MATLAB to analyse the aeroelastic behaviour of a coupled flexible cantilever wing with a variable number of flexibly mounted propellers/rotors. Reed’s model is employed to model the propeller dynamics, with the structural model of the wing being derived through the assumed-mode Rayleigh-Ritz method. The aerodynamic model of the wing was obtained from a combination of the modified strip theory and Theodorsen’s unsteady aerodynamic theory. The proposed coupled aeroelastic model can successfully estimate both wing and whirl flutter in DEP wings through validations with results from the literature. The model was then used for several parametric analyses investigating the effects of propeller spanwise position, advance ratio and rotor radius on the stability of the integrated wing-propeller system. The parametric studies demonstrated that advance ratio and rotor radius have a significant effect on the stability of the coupled wing-propeller model. It was found that increasing the advance ratio has a destabilizing effect, whereas increasing the rotor radius has a stabilizing effect.