Numerical Study of the Aerodynamic Performance of Dragonfly Wing Airfoils for Small RPAS

Dragonflies highlight among four-winged insects for their decoupled forewing and hindwing operation, which allows for extraordinary flight maneuvers and even gliding, a rare capability in insects. Dragonfly wings exhibit complex aerodynamics due to their undulating structure. This work explores how variations in this corrugation and the orientation of the leading edge affect the aerodynamic performance of a conventional wing of a small RPA (designed between INTA and ETSIAE) and evaluate the feasibility for integration into small RPAS. For this purpose, an experimental analysis has been conducted using three dragonfly-inspired cross airfoils, and compared them with the Eppler 186 airfoil (of the vehicle). The obtained data has demonstrated that all dragonfly configurations delay the stall condition from 15º to 20º, and the DW-C presents a significantly higher lift coefficient across the entire range of angles of attack. During cruise flight, the lift coefficient is eight times greater than that of the conventional airfoil, while the aerodynamic efficiency achieves a notable improvement of two times higher, highlighting its superior performance under these conditions.