Effects of Surface Flats on the Performance of a Remotely Piloted Aircraft

Effects of surface flats on the performance of a remotely piloted aircraft was studied through wind tunnel experiments. Wings were designed in CATIA and then rapid-prototyped using Embry-Riddle's rapid-prototyping facilities, yielding acrylonitrile butadiene styrene plastic wing representations. Two 101.6 mm chord c wings were manufactured and pressure-tapped. The so-called modified wing was composed of flats on the upper and lower surfaces, consistent with typical R/C modeling construction technique. The tunnel freestream velocity was measured using the Flow-Kinetics LLC FKT 1DP1A-SV meter. At an angle of attack of -4 deg, the upper surface pressure distribution is similar for both wings. The lower surface flat appears to causes a drop of pressure just aft of its forward junction. Drag data indicated a significant drag rise due to the localized separations over the airfoil with flats. Wake traces showed the drag embodiment as a greater peak momentum deficit with a slight increase in the wake width. Copyright © 2009 by the authors. Published by the American Institute of Aeronautics and Astronautics, Inc.