Wing rock is an unsteady aerodynamic phenomenon where the stability in the aircraft’s lateral directional modes are lost. This causes unstable roll oscillations of the aircraft. The main causes are vortices that appear at high angles of attack, negative roll damping, and flow instabilities around the wing and body of the aircraft. This could occur during shock-induced separations in the transonic regime. The interaction of these vortices with the flow field over the aircraft wings causes the wing rock. This phenomenon is common in high performance fighters and high G maneuvers. Wing rock can happen during maneuvering flight or landing. A flow instability creates low roll damping at low roll angles which then increases in amplitude until a stable limit cycle is reached at higher roll angles where the roll damping increases. There are two types of wing rock, one that happens at high AOA and one that happens at low AOA. Wing rock is associated with a change in sign of the roll-damping derivative or instabilities in the longitudinal or lateral control modes.
The eigenvalues of the monodromy matrix determine the stability of the system.
[[Wing Rock in Fighter Aircraft]]
[[High AOA Wing Rock]]
[[Low AOA Wing Rock]]
[[Lateral Control Divergence Parameter]] – can help to predict departure sensitivity
[[Limit Cycles]] – higher roll damping at higher roll angles causes the limit cycle behavior
[[Monodromy Matrix]]
[[Missile Kinematics]] – can exhibit similar wing rock behaviors at high AOA.
- WingRockPrediction