Nonlinear aeroelastic behavior of a panel impinged by oscillating shock

The aeroelastic responses and nonlinear behaviors of a two-dimensional panel impinged by an oscillating Mach stem shock are investigated through theoretical analysis. Through the nonlinear descriptors, such as Poincaré maps and Largest Lyapunov exponents, the panel with oscillating shock impingement is found to exhibit multiple responses, including single/multi-periodic limit cycle oscillation, quasi-periodic motion, and chaotic motion. Without altering the in-plane force, which is the principal source of structural nonlinearity, the shock oscillation complicates the nonlinear behaviors of the panel. With shock oscillation, the original divergence instability is transformed into post-divergence limit cycle oscillation, and the flutter response exhibits rich nonlinear characteristics. The effect of initial shock impingement location, shock oscillating amplitude, and shock oscillating frequency are disclosed through the bifurcation diagram, which significantly influences the nonlinear characteristics of the panel response. By reasonably adjusting the shock oscillating parameters, unpredictable nonlinear behaviors, especially chaotic motions, can be avoided.

Duke Scholars

Author Earl H. Dowell Thomas Lord Department of Mechanical Engineering and Materia ...