Sectional lift coefficient of a rotating wing at low Reynolds number

Abstract

To investigate the characteristics of sectional lift coefficient, we conduct three-dimensional simulations of flow around a low-aspect-ratio wing in rotating motion at a low Reynolds number (Re=136). Three different shapes of flat plate wings (fruit-fly, rectangular, and triangular wings) are considered but keeping their aspect ratio (wing span/wing chord) the same at 3.74. Each wing rotates at a constant angular velocity and the angle of attack (AoA) is fixed during the rotation. During the first rotation, the sectional lift coefficient decreases from the wing root to the wing tip for all cases. After a few rotations, the wing is exposed to the downward motion generated from the previous rotation and thus the sectional lift coefficient is overall reduced. The effect of wing shape on the sectional lift coefficient are explored with three different types of thin plate wings. We also investigate the behavior of sectional lift coefficient at higher Reynolds number.