Wind Tunnel Experiment of UTM-SACCON UCAV Configuration

Abstract

The rapid development and advancement in unmanned aerial vehicle/unmanned combat aerial vehicle (UAV/UCAV) has triggered the increasing interest in development of UAV/UCAV. Numerous of the research performed experimentally and numerically in order to have a better understanding on the complicated flow behavior above low sweep blended delta wing design which commonly used in UCAV configuration. A research group called AVT-161 is one of the pioneer research programmes in the UCAV configuration throughout generic model SACCON. However, the current knowledge on the SACCON configuration is very limited to certain angle of attacks and flow conditions such Reynold number. This current research will highlight the aerodynamics and flow characteristics of the SACCON at Reynolds number of 0.51×10⁶ and 0.78×10⁶ towards different angle of attacks. A semi-span wind tunnel model was designed and fabricated with the capability to install pressure taps on several positions inside the model. The experiments were conducted in a closed-circuit low speed wind tunnel at speeds of 17 and 26 m/s that corresponding to 0.51×10⁶ and 0.78×10⁶ Reynolds numbers based on model mean aerodynamic chord, respectively. The angles of attack were varied from -10° to 30°. During the experiment, two measurement techniques were employed on the wing, which were the steady balance measurement and surface pressure measurement. The findings highlight the effects of Reynolds number toward the aerodynamic coefficients and pressure distribution above the wing. The experimental data conclude that the aerodynamic characteristics of SACCON wing is influenced by flow structure above the wing. The SACCON wing exhibits three major vortex structures which are apex vortex, thickness vortex and tip vortex. Additional suction peak is observed near the trailing edge downstream from wing at higher angle of may suggest that another vortex developed in the region. The current findings may contribute to a better understanding of flow physics on UCAV configuration.