The Growth of Vortices in the Vicinity of a Wall by Relative Acceleration of Elastic Moving Airfoil

Abstract

A lot of studies of the flow field around unsteady airfoils have been reported over the years. In particular, the elastic moving airfoil has recently gained attention in the developing Micro Air Vehicle, because a flying animal’s wings have elasticity, and elastic deformation may affect the vortex growth process. The flow field around an elastic moving airfoil has been researched mainly by numerical ways and there have been a few studies performed by experimental ways. Based on these studies, elastic deformation is considered to greatly affect the behavior of vortices generated in the vicinity of a wall. Therefore, we performed PIV measurement for vortex flow in the vicinity of a wall of pitching and heaving elastic NACA0010 to quantitatively clarify the growth of vortex in the vicinity of a wall due to elastic deformation by imparting pitching and heaving motion. Moreover, we evaluated the variation of relative acceleration as a new parameter to evaluate the elastic deformation and time variation of vorticity of vortices generated in the vicinity of a wall. Finally, we clarify the relationship between the growth of vortices in the vicinity of a wall and the relative acceleration of the airfoil by elastic deformation.