Aerodynamic studies over a manoeuvring UCAV 1303 configuration

Abstract

AbstractThe flow past an unmanned combat air vehicle (UCAV) 1303 was investigated in a water tunnel in an effort to understand the complex flow field. The UCAV 1303 is characterised by a non slender, 47° swept-leading-edge delta wing, with a cranked trailing edge, a cropped wing tip and a fuselage. It also has no vertical tail. Dye visualisation pictures and five-axis strain gage load data were obtained on a 1:72 scale model in both steady flow and while the model executed preprogrammed manoeuvres. From the strain gage data, body axis force and moment data were derived. In addition to some similarities, comparison of the flow features observed with those of more well known slender delta wing flows showed some remarkable differences such as tip-stall, the presence of two like-sense vortices on the same side of the wing, their simultaneous spiral and bubble bursting. This paper predominantly discusses the flow visualisation results and attempts to correlate the load data to some of the observed flow features.