The efects of flexibility on the performance of flapping airfoils

M. VANELLA, T. FITZGERALD, S. PREIDIKMAN, E. BALARAS, AND B. BALACHANDRAN

Salt Lake City, Utah, USA

Conferencia; The 2007 APS Division of Fluid Dynamics 60th Annual Meeting (DFD07); 2007

American Physical Society - Division of Fluid Dynamics

The majority of experimental and numerical studies related to °apping °ight have been exploring the relation of the thrust coe±cient and propulsive e±ciency to the wing geometry and kinematics. Wing °exibility has received less attention and as of today it remains unclear if it can be exploited for better performance at low-Reynolds-number °apping °ight. To bridge this gap we performed simulations of a two-dimensional, two-component wings connected by a hinge with a torsional spring. The motion of the lead body has prescribed kinematics, while the trailing body motion is passive. One of the primary outcomes of this work is that nonlinear resonances play an important role in the performance of a given °apping wing system, mainly by modifying the formation of leading and trailing edge vortices. For the °exible pro¯le used, the mean values of lift and drag forces, and the ratio of lift to drag are enhanced when the system responds in the nonlinear resonance region.