COMPARISON OF SUKHOI T-50 PAK-FA AND F-22 RAPTOR-LIKE FIGHTERS MODEL FLOW VISUALIZATION USING GAMA WATER TUNNEL

Comparison of Sukhoi T-50 PAK-FA and F-22 Raptor-like fighters' model flow visualization were investigated using water tunnel. Flow visualization testing used a water tunnel because it could reveal the vortex dynamics phenomenon easily visually. The vortex dynamics and the performance of both fighters were examined at 0.1 m/s test section flow. The test used Reynolds number 6.577 x 103 on a 1: 100 scale model. Testing was conducted at varying the angle of attack of 0° - 60°. The flow visualization was measured using dye injection method. The result of the research using GAMA water tunnel showed the aerodynamic force and vortex dynamics phenomenon that showed the difference in lift and drag coefficients. The results of this visualization showed the formation of vortex nuclei that occur in the wings of the aircraft model. The vortex core was a source of lift in delta type aircraft. The influence of rolled-up vortex would form the central part as a vortex core which had very low pressure so that it functions as the formation of lift force. Visualizing the vortex core was characterized by the formation of an ink injection line until the ink broke or damaged the flow. The highest lift coefficient occurred on both models about 1.18 on the angle of attack of 40° for F22 Raptor and PAK-FA T-50 model at AoA 45o