Different Aerodynamic Performance of Gliders with Different Wing Shapes Referenced from Birds

Abstract

A glider is a kind of aircraft that does not have power to drive. All its movement are controlled by air. Therefore, a high aerodynamic shape is required by a glider. Gliders nowadays have wings with significantly high aspect ratio. Its wing shape can be approximately seem as a rectangle or trapezoid. However, gliding is not a invention of human, there is a substantial number of animal is using this fly style, especially birds. Their wing shapes are more various, this might be due to the biological structure of birds, or it could be an inevitable result of natural selection. The objective of this paper is to compare and study the aerodynamic performance of wing shapes of two major gliding birds with the standard rectangular wing. The shape of the wing is inspired by seabirds and eagles. The experiment requires four models, Each model was thrown and its flight trajectory was recorded. The experimental results show that under the same aspect ratio, the wings of eagles exhibit higher aerodynamic performance. Its gliding Angle is significantly reduced, which means a higher lift-to-drag ratio. The possible reason for this is that the feathers on the outer side of the wing, On the higher aspect ratio, the shape of the wing only has a slight impact, with a decrease in the glide angle and a increase in speed. Nevertheless, The wing design that imitates the polyhedral wing of albatrosses has significantly improved flight efficiency. the meaning of this research lies in designing and optimizing the aerodynamic shape of the wing by referring to birds in nature, thereby enhancing the aerodynamic performance of the glider, which can made contributions in all fields of aerospace.