The concept of active circulation control has been proposed to improve lifting performance for various applications. It is mostly suggested as a flow control system to replace or minimize mechanical flaps or as a boundary layer control mechanism in the aerospace industry. The efficiency of these systems has always been the main concern due to increased drag and pumping requirements. These concerns are negligible for high-speed marine crafts as the hydrodynamic drag acting on the hull is dominant. This research investigates the aerodynamic performance of a NACA 4412 airfoil that was modified for circulation control to determine the influence of the trailing-edge geometry, blowing coefficient, angle of attack, and height above the ground to improve the efficiency of a wing-in-ground craft and shorten its take-off distance. The flow is subsonic and incompressible, and the chord Reynolds number is 1.7 × 106. A computational fluid dynamics investigation has determined that significant increases in lift can be attained through circulation control relative to the original NACA 4412 airfoil, and it is not significantly influenced by the airfoil height except when there is an extreme ground effect. Also, the lift augmentation increases approximately linearly with the blowing momentum coefficient and angle of attack. The study shows a significant improvement in the take-off length, which was reduced from 465 m to between 360 and 150 m according to the height above the ground plane, angle of attack, and the momentum coefficient when the Coanda surface is 30 mm. The circulation-controlled NACA 4412 could achieve 66% effectiveness compared to a currently available vehicle.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)