Scientists from Hiroshima University undertook a study of dragonfly wings in order to better understand the relationship between a corrugated wing structure and vortex motions. They discovered that corrugated wings exhibit larger lift than flat wings. The researchers set out to determine if the corrugation of a dragonfly's wing is a secret ingredient for boosting lift. While past research has largely zoomed in on the steady flow around the wing during forward motion, the impact of vortices spawned by its corrugated structure on lift has remained a mystery. The wing surfaces of insects like dragonflies, cicadas, and bees, are not flat like the wings on a passenger plane.

Earlier studies have shown that corrugated wings, with their ridges and grooves, have a better aerodynamic performance than smooth wings at low Reynolds numbers. In aerodynamics, the Reynolds number is a quantity that helps predict the flow pattern of fluids. The earlier aerodynamic studies on corrugated wings have contributed to applications in small flying robots, drones, and windmills. Yet scientists have not fully understood the mechanism at work because of the complex wing structure and flow characteristics. They focused their study on the period between the initial generation of the leading-edge vortex and subsequent interactions before detachment.

However, their work focused on the aerodynamics of insect flight, where the flow is typically three-dimensional. If these results are expanded to a three-dimensional system, we expect to gain more practical knowledge for understanding insect flight and its application in the industry. Looking ahead, the researchers will focus their investigations on three-dimensional models. They kicked things off with a two-dimensional corrugated wing model in a sudden burst of motion. Now, they embark on the quest to explore the lift-boosting across a broader range of wing shapes and motions. Their ultimate goal is crafting a new bio-inspired wing with high performance by our lift-enhancing mechanism.