Investigation of Highly Unsteady Aerodynamics of Flapping Wings With/Without a Flexible Training Edge Using High Resolution MTV Measurements
Abstract
A three-year coordinated experimental and computational investigation is carried out to study the fundamental aerodynamics of oscillating airfoils in the chord Reynolds number range of 2,000 - 60,000. The objective of the investigation is to establish the connection between the airfoil motion trajectory, the trailing edge flexure, the time history of vorticity flux at the trailing edge, the pattern of shed vorticity and its evolution, and the conditions for generation of thrust/drag and lift. The results show that the non-dimensional spacing and circulation of the wake vortices as well as the mean thrust coefficient acting on the airfoil are similar for both rigid and flexible airfoils at the same Strouhal number, if the latter is computed using the actual airfoil's trailing edge oscillation amplitude. Furthermore, it is discovered that the Reynolds number has a significant influence on the reduced frequency and Strouhal number at which the wake vortex arrangement switches to the "reversed" von Karman street configuration and the mean streamwise force changes from drag to thrust. This study has also resulted in the development of new measurement techniques that will make possible in the future measurements of the pressure and shear stress distribution on flexible and moving surfaces.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 14, 2013
- Accession Number
- ADA587858
Entities
People
- Admed M. Naguib
- Manoochehr M. Koochesfahani
Organizations
- Michigan State University