Large-scale multidisciplinary design optimization of a NASA air taxi concept using a comprehensive physics-based system model
Marius L. Ruh, Andrew Fletcher, Darshan Sarojini, Mark Sperry, Jiayao Yan, Luca Scotzniovsky, Sebastiaan P. van Schie, M. Warner, Nicholas C. Orndorff, Ru Xiang, Anugrah Jo Joshy, Han Zhao, Joshua Krokowski, Hyunjune Gill, Seongkyu Lee, Zeyu Cheng, Zhi Cao, Chris Mı, Christopher J. Silva, Lauren G. Wolfe, Jiun‐Shyan Chen, John T. Hwang
Abstract
Aircraft conceptual design is a high-dimensional optimization problem, involving up to hundreds of continuous design variables and constraints. The design of novel aircraft concepts such as electric vertical takeoff and landing (eVTOL) vehicles can benefit from the systematic exploration of the design space through the use of gradient-based optimization. In this paper, we demonstrate the application of large-scale multidisciplinary design optimization (MDO) to NASA's lift-plus-cruise electric air taxi concept, using low and mid-fidelity physics-based simulations to model the aircraft. We improve the modeling fidelity from our previous work on the same air taxi concept through refined rotor-aerodynamic and aeroacoustic models as well as in-the-loop structural analysis. In addition, we expand the scope of the analysis to include several steady design conditions, a quasi-steady transition maneuver, structural sizing conditions, as well as one-engine-inoperative (OEI) scenarios, amounting to 18 design conditions. To perform the analysis and optimization, we use a newly developed software library called the Comprehensive Aircraft high-Dimensional Design Environment (CADDEE), which facilitates the integration of all discipline models. We solve a gross weight minimization problem with over 300 design variables and over 200 constraints, spanning all modeled disciplines. Results show a decrease in gross weight of 10% after a total optimization time of about 17 hours. These results demonstrate the effectiveness of applying of large-scale MDO to the aircraft conceptual design problem.