Multifidelity modeling of deployable wings: Multibody dynamic simulation and wind tunnel experiment

Slender deployable wings have attracted interest for use in Mars, Titan, and high-altitude flights. Such wings are composed of multiple bodies connected by hinge joints and can be deployed or folded spanwise during flight. A deployment simulation model is required for their design. This paper proposes a multifidelity multibody modeling method that uses a new asymmetrically gradient-deficient absolute nodal coordinate beam element. The proposed method addresses the drawbacks of conventional elements, namely, numerical locking and the need for a large number of generalized coordinates, by exploiting a structural characteristic of a slender wing. It enables computationally efficient low-fidelity rigid multibody simulation and more realistic high-fidelity flexible multibody simulation, both accomplished using a consistent modeling process and the same simulation program architecture. Additionally, the low-fidelity and high-fidelity models can be coupled with an aerodynamic model using a consistent coupling methodology. To validate the proposed modeling method, wing deployment experiments were performed in a wind tunnel at the Institute of Fluid Science, Tohoku University. The simulation results obtained using the proposed modeling method were found to be in good agreement with those of the wind tunnel experiments, even when the wings experienced large geometrically nonlinear deformations.