Aerodynamic Characteristics of Low-Aspect-Ratio Wings with Various Aspect Ratios in Low Reynolds Number Flows

The effect of the aspect ratio on the stall characteristics of low-aspect-ratio wings is experimentally investigated at a Reynolds number of 5.2×104. The aspect ratio ranges from 0.5 to 1.5 at intervals of 0.1. The aerodynamic coefficients of thin rectangular wings are measured in a low-speed wind tunnel. It is found that the aerodynamic characteristics of low-aspect-ratio wings are significantly sensitive to the aspect ratio. The maximum lift coefficient increases as the aspect ratio decreases toward unity. On the other hand, the difference in lift-to-drag ratio is negligible at large angles. Hysteresis during a stall occurs when the aspect ratio is within a narrow range. The span of the hysteresis loop has its peak at an aspect ratio of 1.0. The discussion also includes the analysis of lift components and flow visualization.