Determining Aerodynamic Characteristics of a Micro Air Vehicle Using Motion Tracking

作者：Uhlig Daniel V^*; Selig Michael S

来源：Journal of Aircraft, 2013, 50(5): 1481-1490.

DOI：10.2514/1.C031996

The aerodynamic performance of small-scale fixed-wing flight is not well understood, and flight data is needed to gain a better understanding of the aerodynamics of micro air vehicles. The flight characteristics of micro air vehicles are difficult to measure because the small size and low weight prevent the use of conventional onboard instrumentation systems. In this research, an offboard motion tracking system captured the motion trajectory during the flights of a small off-the-shelf radio-controlled airplane that weighed 14.44 g (0.5094 oz) and had a span of 37.47cm (14.75 in.). The recorded motion-path time histories were analyzed to determine the aerodynamic characteristics of the airplane during unpowered flight. The results presented show the longitudinal aerodynamic characteristics of the micro air vehicle over a wide range of angles of attack at a nominal Reynolds number of 25,000. Specifically, lift and drag characteristics of the airplane were obtained from the analysis of the flight trajectories during quasi-steady nominal gliding flight, as well as unsteady high angle-of-attack flight. The nominal-gliding flights showed an almost linear lift curve and small unsteady effects that were in part due to the angle-of-attack rate. During the unsteady high angle-of-attack flight, as would be seen during perching maneuvers, deep stall maneuvers, and highly dynamic flight in confined spaces, the unsteady effects of rapid changes in the angle of attack significantly increased the lift coefficient during pitch-up maneuvers and then decreased the lift coefficient during pitch-down maneuvers. By using numerous flight tests in both regimes (nominal-gliding and unsteady high angle-of-attack flight), the results show the effect of the angular rate and expand on the limited existing work. The flight-test results presented show the influence of unsteady aerodynamic effects on the longitudinal aerodynamic characteristics of a micro air vehicle in both quasi-steady nominal gliding flight and unsteady high angle-of-attack flight.

• 出版日期2013-10