Flow Field Characteristics of Translating and Revolving Flexible Wings

This study explores the effects of rotational mechanisms on the characteristics of the leading edge vortex (LEV) by comparing translating and revolving flexible wings that are started from rest. Tomographic particle image velocimetry (tomographic-PIV) technique was employed to acquire three-dimensional flow fields for the revolving wings, while planar flow fields for the case of translating wings were acquired via 2D2C-PIV measurements. The comparison of flow fields between the two motion kinematics reveals similar behavior of the vortical structures yet the LEV circulation in the translating wings has higher values. The LEV centroid in the revolving cases stays above the leading-edge, while in the translating wings, it always remains at a lower position. The effect of high flexibility results in the retention of LEV closer to the wing surface for both cases.