THE PROGRESS OF STUDIES OF UNCOMMANDED MOTION AND ITS SUPPRESSION OF FLYING VEHICLE WITH HIGH MANUEVERABILITY

High maneuver ability might be achieved by a flying vehicle at high angles of attack. The uncom-manded motions of aircraft can be generated at high angles of attack in flying with high maneuver ability. Therefore this problem should be considered in the early phase of aircraft design and the complicated flow behaviors and characteristics of uncommanded motions of the designed configuration will be studied to reveal the dominant flows to drive uncommanded motions. The flow control techniques are developed to suppress the uncommanded motions. In the present paper it is pointed out that the forebody asymmetric vortices are very sensitive to the micro-perturbation on the model nose. For a long time it is wrongly believed that the forebody asymmetric vortex flow is non-deterministic. It is found that if a micro-manual-perturbation is added on the nose tip of model the asymmetric vortex flow can be reproduced. Based on the manual-perturbation technique the evolution of the asymmetric vortices related with the circumferential angle of perturbation is revealed. The dominant flows are discovered, which drive the uncommanded motions of two typical configura-tions. The perturbation control techniques are developed to suppress those uncommanded motions by rotating the tip-perturbation and setting tip-perturbation on a proper location to make two pair of asymmetric vortices in the phase reversal. The micro-perturbation plays a very important role in the non-liner separated and vortex flows at high angles of attack. The roles of micro-perturbation are the key in controlling the non-linear vortex flows, which drive the uncmmande motions.