BIFURCATION ANALYSIS OF AIRCRAFT HIGH ANGLE-OF-ATTACK FLIGHT DYNAMICS

A new approach is presented for analyzing nonlinear and high-a dynamic behavior and stability of aircraft. This approach involves the application of bifurcation analysis and catastrophe theory methodology (BACTM) to s pecific phenomena such as stall, departure, spin entry, flat and steep s pin, nose slice, and wing rock. Quantitative results of a global nature are presented, using numerical techniques based on parametric continuation. It is shown how BACTM provides a complete representation of the aircraft equilibrium and bifurcation surfaces in the s tate-control space, u sing a rigid body model and aerosurface controls. Also presented is a particularly useful extension of continuation methods to the d etection and stability analysis of stable a ttracting orbits (limit cycles). The use of BACTM for understanding high-a phenomena, especially spin-related behavior, is discussed.