%A FU Junquan, SHI Zhiwei, GENG Xi, ZHU Jiachen, WANG Lishuang, WU Dawei, PAN Lijun %T Longitudinal stability of blended-wing-body aircraft based on experimental bifurcation analysis %0 Journal Article %D 2022 %J Acta Aeronautica et Astronautica Sinica %R 10.7527/S1000-6893.2020.24931 %P 124931-124931 %V 43 %N 1 %U {https://hkxb.buaa.edu.cn/CN/abstract/article_18323.shtml} %8 2022-01-15 %X Bifurcation analysis and the catastrophe theory are used to study the longitudinal stability of Blended-Wing-Body (BWB) aircraft. Equilibrium branches of the angle of attack with the elevator are obtained, and stability of the branches and the catastrophe points analyzed. Then bifurcation analysis is introduced into the virtual flight tests to physically track the equilibrium branches, enabling the experimental bifurcation analysis research in the wind tunnel. A pseudo-linear controller based on the nonlinear dynamic inverse is designed, with the open-loop and closed-loop experimental bifurcation diagrams obtained and analyzed. The comparative analysis shows that the theoretical bifurcation analysis and the open-loop experimental bifurcation analysis are basically consistent in the range of small angles of attack, verifying the feasibility and accuracy of the experimental bifurcation analysis method. The longitudinal instability of the BWB aircraft is mainly caused by the sudden changes of C. The closed-loop experimental bifurcation analysis realizes the nonlinear global stability control, transforming the unstable equilibrium branch into a stable one through the longitudinal nonlinear controller.