Flapping, Flexible Plates in Close Proximity to a Free Surface

Deriving inspiration from manta rays, reconfiguration of flexible structures can provide desirable thrust to serve as an alternative propulsion method. The scope of the research project includes understanding the fluid-structure interaction of a very flexible flapping plate with prescribed vertical oscillatory motion. This talk will consist of an exploration of passive reconfiguration of the flapping plate at various distances from the free surface. Plate deformation will be significant due to the low flexural rigidity of the structure. The deforming side view of the plate will be measured using high-speed video images and a gradient based edge detection technique. Measurements of the surrounding fluid will include drag on the plate, fluid pressure, and fluid velocity surrounding the plate. At distances far away from the free surface, the flapping plates will reconfigure to a streamlined shape which decrease drag on the structure. As the structure is raised in the water column, the deformed shape will change based on its proximity to the free surface as waves are generated.