Highly Flexible Plates Interacting with a Free Surface: Passive Reconfiguration

Passive reconfiguration of flexible structures readily occurs in biological structures through fluids such as air and water. Past studies on seagrass in water or leaves in the wind show that flexible structures conform to more streamline configurations under influence of a flow field. As a result of the shape change, the surrounding flow field is also altered. Another important aspect to consider again takes inspiration from nature by observing the swimming motions of animals such as a manta ray. The manta ray activates its muscles, which we model as a change in plate stiffness in this study. This is called active reconfiguration and is the main motivation for this project. Few studies have involved understanding of passive or active reconfiguration near a free surface, the interface between air and water. In this talk, results will be discussed on the passive reconfiguration of flexible plates. Experiments and modeling results will be shown of water entry of a pair of plates with enclosed and cantilevered boundary conditions. Experiments of a flapping plate with prescribed vertical oscillatory motion at varying distances from the free surface will also be presented. Finally, discussions of the future directions of this project including the component on active reconfiguration of the plates will be presented. The work from this talk is funded primarily by the National Science Foundation Grant.