Dynamic test experiment system of single degree of freedom of Φ3.2 m wind tunnel

Abstract

Post-stall maneuverability is a key technical indicator for modern fighter. It requires a fighter to maintain excellent dynamic behaviors at a high angle of attack. The dynamic stability derivative is a design input off light control system and one of its important sources is the wind tunnel test. In order to meet stricter quality requirements of test data, China Aerodynamics Research & Development Center (CARDC) has set up a forced oscillation dynamic test system based on single degree of freedom in the open test section of Φ3.2 m wind tunnel. Based on the electronic cam, in this system, the servo motor-decelerator directly drives the supporting rod. The system simplifies the structure of device, reduces the number of moving parts as well as the mechanical clearance. Features of the system include: (1) a large variation range of frequencies and amplitudes, a higher control precision and step-less regulation; (2) independent variation of angle of attack and sideslip angle so that the combination of angle of attack and sideslip angle can be more convenient with higher test efficiency; (3) a small wind tunnel wall interference and support interference. Same set of devices can enable small amplitude dynamic derivatives test, large amplitude oscillatory test, and static force measurement, all of which contribute to a consistent measurement basis. With this test system, we developed a simplified fighter model dynamic test, obtaining dynamic derivatives and unsteady aerodynamic loads. Results of our tests verified the rationality and reliability of data as well as a high precision of repeatability.