Flight of a tumbling elastic wing and aggregation of floating particles
Department of Physics, Clark University
We discuss two distinct experiments. Motivated by the effect of wing elasticity on flight and seed dispersal, we examine the shape and trajectory of a thin rectangular sheet of paper as it falls and autorotates in air. In particular, we find that bending occurs above a critical length in much the same way that buckling occurs in a compressed beam. We demonstrate that this bending is caused by the centripetal force associated with its tumbling motion. Then, we will discuss the geometrically constrained aggregation with floating spheres at the air-liquid interface. A short range attractive force can be induced by careful choice of buoyancy and capillarity to create self-assembled particle structures which can be tracked by imaging. We characterize the aggregates and compare and contrast our results with those reported in thermal and athermal particle systems.