Experimental Study on Aerodynamic Characteristics of PAR-WIG

To understand the aerodynamic characteristics of power- augmented-ram wing-in-ground (PAR-WIG), measurements of lift, drag and moment acting on a low aspect wing were carried out in a towing tank. A pair of model propellers were arranged in front of the wing, the Reynolds number was approximately 3x105. It is shown that lift and drag of the wing increase remarkably due to the PAR effect when the wing is close to the water surface. The lift drag ratio decreased considerably. The trailing edge flap works to significantly increase the PAR effect. The lift gradient versus angle of attack becomes negative value at large angle of attack. Further studies such as flow visualization and pressure measurement on the wing surface are necessary to understand the mechanism of the PAR effect.