Transonic Limit Cycle Oscillations of the Benchmark Supercritical Wing

This paper considers transonic flutter mechanisms of the Benchmark Supercritical Wing, a model under study in the Aeroelastic Prediction Workshop series. Flutter boundaries are mapped out across an angle of attack sweep at Mach 0.8, utilizing both time-domain and linearized frequency-domain solvers, manual meshes and adapted meshes, and various governing equations. With increased angle of attack, linearized and finite amplitude flutter predictions exhibit differences above 3◦ as the flow begins to separate; the latter predictions are found to be driven by subcritical limit cycle oscillations whose strength increases with angle of attack. Moderate perturbation values provide a stability boundary at 5◦ which matches the experimental data, but it is not clear how the experimental perturbation, from one test condition to the next, can be reasonably characterized.