Effects of Propeller Position and Rotation Direction on the Ishii Wing at a Low Reynolds Number

Abstract

The aerodynamic characteristics of a wing in a propeller slipstream were investigated at a low Reynolds number. The e ff ects of propeller position and rotation direction on the wing were clari fi ed by aerodynamic measurements and particle image velocimetry. The propeller positions were the center and tip of the wing model, whereas the rotation directions were clockwise and counterclockwise. The center propeller con fi guration with a clockwise rotation showed a constant pitching moment and increased the lift-to-drag ratio. This was caused by the high-speed propeller slipstream (i.e. 12 and 10m / s on the upwash and downwash sides, respectively) and the wingtip vortex e ff ect on the slipstream separation. The separation point at an angle-of-attack of 18° was delayed from x / c µ 0.1 to 0.3 by the wingtip vortex. Hence, the following two factors must be considered to enhance the aerodynamic characteristics of a Mars airplane: (i) the ratio of the area of the upwash and downwash sides of a wing in a propeller slipstream, and (ii) the e ff ect of the wingtip vortex on the propeller slipstream.