EFFECT OF WINGLET CONFIGURATIONS ON AERODYNAMIC PERFORMANCE OF WING-IN-GROUND CRAFT

Abstract

Wing-in-ground (WIG) craft is a marine vehicle designed to fly over the sea using the interaction between the wings and ground, known as ground effect. WIG has the benefits in terms of cost and operations. However, in spite of these benefits, WIG has weaknesses including the large vortex formed at the wing tip that affect the overall drag and fuel consumption.To compensate these drawback, this study was conducted to investigate a variation of winglet design to increase the performance of the WIG in terms of Lift-to-Drag Ratio (C_L/C_D). Experiments were carried out in the subsonic wind tunnel, Longwin LW-9300R located at Wind Tunnel Lab, Faculty of Engineering UPNM. The winglet was investigated using different dihedral angles, which were 30°, 45°, 60°, 85° and 90°. The model was tested in two conditions; without ground as the baseline case and with Ground Effect (GE) condition. In addition, three different winglet heights were also tested. From the results, it was found that the best winglet configuration was h/c = 0.09, dihedral angle of δ=90° and winglet height of s/c = 0.09, with an improvement of nearly 65% from the baseline case.