Numerical Study of Microblowing System Effect on Reducing the Drag Force of a SC(2)-0710 Supercritical Airfoil

The main purpose of this study is to design a microblowing system to reduce the drag force of an aircraft with SC(2)-0710 supercritical airfoil. For this purpose, the subsonic turbulent flow around the airfoil is simulated by the Fluent software. The numerical simulation has been investigated in cruise conditions at the Mach number of 0.4-0.6 and attack angle of 0º-3º. The turbulent flow is simulated using the SST k-ω turbulent model, and the UDF code is written in C programming language to apply the microblowing technique. The numerical results have been compared with the available experimental and numerical data, and they have had in accordance with each other. The results showed that the friction drag coefficient decreases with increasing the blowing fraction. On the other hand, in attack angle of 0º-2º, the increase in blowing fraction causes to increase the pressure drag coefficient of the airfoil with its microblowing compared to the airfoil without it. In fact, the microblowing has created the reverse effect on the pressure field around the airfoil. The results have been examined for six microblowing positions. It was detected that the greatest reduction in the total drag coefficient has occurred when microblowing has been located near the leading edge on the suction side. Also, it was observed that the lift force decreases by applying the microblowing, but the selected position has the least effect on reducing the lift coefficient. Besides, the results showed that the suitable results (that is, the lowest drag force) have been attained at the attack angle of 3º. Finally, after the numerical studies, the proposed system is designed, and assembly and disassembly maps have been provided.