Numerical and Experimental Simulations of Flapping Wings

Abstract

This paper presents recent progress in a continuing investigation of the aeromechanical aspects of unsteady flapping wings for micro air vehicles (MAV). Numerical simulations were performed for two-dimensional (2D) pitching-plunging airfoils and three-dimensional (3D) flapping wings, mainly at hover conditions, using an in-house code called INSflow. The results were compared with available experimental data obtained in the water tunnel at the NRC-IAR. The investigation revealed that, at hover conditions, the vortices formed during the airfoil plunging motion may remain near the airfoil and affect new vortex formations, and thus the integral aerodynamic performance. In addition, the flow around the 3D insect-like wing is fully three-dimensional. The tip flow affects the flow separation, reducing the separation intensity. Two-dimensional calculations may over-predict the separation and the shedding vortices, thus affecting the generation of aerodynamic forces.