Forebody Flow During the Wing Rock Over Low Swept Wing/Body Configuration in High Rate Pitching-up

Over the configuration of a pointed ogive-cylindrical body with 30° swept wing, wind tunnel experiments are conducted to investigate the wing rock motion in pitching-up as well as the flow structure responsible for it. Results show that wing rock would present as a sinusoid like motion during angle of attack 20°∼85° in high rate pitching-up.And the evolvement of forebody vortices with angle of attack should be responsible for the sinusoid like motion. Firstly, the wing rock is triggered by forebody asymmetric vortices at moderate angle of attack (about 30°). Secondly, the variation of forebody asymmetric vortices with angle of attack sustains the wing rock during angle of attack 30°∼60°. At last, the wing rock after angle of attack 60° is a convergent process of rolling due to the breakdown of forebody asymmetric vortices.