A Comparison of Aerodynamic Models for Optimizing the Takeoff and Transition of a Bi-wing Tailsitter
Keywords
eVTOL, tailsitter, transition, trajectory, optimization, DEP, electric aircraft
Abstract
Electric vertical takeoff and landing (eVTOL) aircraft take advantage of distributed electric propulsion as well as aerodynamic lifting surfaces to take off vertically and perform long-duration flights. Complex aerodynamic interactions and a hard-to-predict transition maneuver from hover to wing-borne flight are one challenge in their development. To address this, we compare three different interaction models of varying fidelity for optimizing the transition trajectory of a biplane tailsitter. The first model accounts for simplified rotor-on-wing interactions using momentum theory, while the other two account for wing-on-wing interactions using a vortex lattice method and rotor-on-wing aerodynamic interactions using blade element momentum theory. One includes the swirl component of velocity and the other neglects swirl. To determine the trajectory, we perform direct collocation on the lowest fidelity model using gradient-based optimization. To compare them, we use the same control inputs obtained in the optimization to integrate trajectories using the higher fidelity models. We find that the higher fidelity models predict power and stall significantly more conservatively than the lowest fidelity model. We conclude that modeling the swirl velocity of the rotor wake and the selected stall model play a significant role in defining the transition trajectory.
Original Publication Citation
Anderson, R., Willis, J., Johnson, J., Ning, A., and Beard, R., “A Comparison of Aerodynamic Models for Optimizing the Takeoff and Transition of a Bi-wing Tailsitter,” AIAA SciTech Forum, virtual, Jan. 2021. doi:10.2514/6.2021-1008
BYU ScholarsArchive Citation
Anderson, Ryan; Willis, Jacob; Johnson, Jacob; Ning, Andrew; and Beard, Randal, "A Comparison of Aerodynamic Models for Optimizing the Takeoff and Transition of a Bi-wing Tailsitter" (2021). Faculty Publications. 4549.
https://scholarsarchive.byu.edu/facpub/4549
Document Type
Conference Paper
Publication Date
2021-1
Permanent URL
http://hdl.lib.byu.edu/1877/7356
Publisher
AIAA
Language
English
College
Ira A. Fulton College of Engineering and Technology
Department
Mechanical Engineering
Copyright Use Information
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