Initial Investigation on the Aerodynamic Performance of Flapping Wings for Nano Air Vehicles

Abstract : A four year project was approved with the purpose of increasing our understanding of the issues concerning the flight of very small air vehicles using flapping wings. This technical memorandum presents the progress made during the first year of the project. The potential impact of this technology on military operations and R&D is first described. The project plan, as revised during the first year, is presented. It combines the development of an ability to capture detailed flow physics using both a highly accurate Computational Fluid Dynamics (CFD) solution and a tailored experimental facility with an engineering type method. The general characteristics of the target Nano Air Vehicle (NAV) to be studied, such as size, mass and wing motion, were established based on system considerations. Standard test cases in 2D and 3D for simulation and experimentation were set up by applying simplifications and scaling arguments to the target NAV. CFD simulations were initiated with the standard two dimensional test case previously defined. The in house INSflow code and the commercially available Fluent code were both used to solve this unsteady incompressible flow. Motion rigs in 2D and in 3D for the NRC IAR water tunnel were designed and are being fabricated. A micro PIV method was also developed. The required equipment, mainly a high frequency laser, was purchased. The system is being implemented.