Research On A Flight Dynamics And Control In Wind Tunnel Based Virtual Flight Test

Post-stall maneuvering capability is one of the most important technical features for the fourth generation and other advanced fighter aircraft. In the process of aircraft design, the post-stall maneuver along with the unsteady aerodynamic characteristics and coupling characteristics of motion makes new demands on the wind tunnel test, flight control and maneuverability evaluation. In view of the highly non-linear coupling characteristics of aerodynamics and the motion during post-stall maneuver, this paper studies one kind of new wind tunnel test technology --the wind tunnel based virtual flight test (WTBVFT) technology, focusing on the flight dynamics and control problems needed to solve in WTBVFT First of all, the paper introduces the basic concept and principle of WTBVFT, and analyzes the role of WTBVFT played in the study of aerodynamics/motion coupling characteristics in the Post-stall maneuver, clearly indicating the mechanism and requirements of post-stall agility criterions which represent the post-stall maneuvering capability. Secondly, using dimensional theory, the paper gives the general similarity criterion which should be used to assess the post-stall agility criterions in WTBVFT, focusing on the similar questions of WTBVFT which is conducted by limiting the translational degrees of freedom and releasing the rotational degrees of freedom of the wind model motion. By analyzing the simulation response of the closed loop system with tracking controller of the angle of attack, the conclusion has been drawn that the response of the angle of attack is close to actual flight. Finally, the control law of model motion in WTBVFT is designed by nonlinear dynamic inversion methods, and the problems which should be solved in future are proposed. The results of the study have certain referential value to the development of the fourth generation and other advanced fighter aircraft.