WIND-TUNNEL INVESTIGATION OF A FIGHTER MODEL AT HIGH ANGLES OF ATTACK

A low-speed wind-tunnel investigation was conducted to examine the aerodynamic characteristics of the flowfield around a 3% scale model of YF-17 lightweight fighter prototype at high angles of attack using laser sheet flow visualization and force and moment measurements. The data indicate a good correlation between the observed flow phenomena and force and moment measurements at various orientations of the model, thus establishing the credibility of such experimental investigations for high-angle-of-attack aerodynamic research. The asymmetric shedding of vortices generated by the slender nose and leading-edge extensions (strakes) of the model dominate the aerodynamic phenomenon between 45- and 65-deg angle of attack. The roll and yaw angles have considerable influence on vortex development and consequently on flow behavior al high angles of attack.