Bifurcation analysis of wing rock and routes to chaos of a low aspect ratio flying wing

Low aspect ratio flying wings have attracted significant attention due to high maneuverability and potential for stealth applications, and their flight dynamics are complex and dominated by nonlinearities. Wing rock is a common quasi-periodic oscillation in low aspect ratio aircraft, which can exhibit chaotic motion under certain conditions. However, the specific characteristics of wing rock in low aspect ratio flying wings and its potential chaotic behavior remain unclear. In this paper, the wing rock motion of a low aspect ratio flying wing is investigated through bifurcation analysis and time-domain responses analysis based on a full-order nonlinear aircraft model. It is found that elevator deflection induces a successive period-doubling bifurcation path, which transitions the wing rock from single-period to multi-period, ultimately evolving toward chaos. Multi-period and chaotic wing rock poses a higher level of danger compared to single-period wing rock, as their trajectories exhibit rapid helical descent similar to spin. These results significantly enhance our comprehension of wing rock in low aspect ratio flying wings and contribute valuable insights to the design of effective recovery strategies for wing rock.