Postinstability Behavior of a Two-Dimensional Airfoil with a Structural Nonlinearity

摘要: A two-dimensiona l airfoil with a free-play nonlinearity in pitch subject to incompressibl e flow has been analyzed. The aerodynamic forces on the were evaluated using Wagner's function and resulting equations integrated numerically give time histories of motion. Regions limit cycle oscillation are detected for velocities well below linear flutter boundary, existence these regions is strongly dependent initial conditions properties airfoil. Furthermore, small structural preloads, narrow chaotic motion obtained, as suggested by power spectral densities, phase-plane plots, Poincare sections histories. this number parameters, including, mass, frequency ratio, damping, preload.