SUMMARY

The objective of this Ph.D. proposal is to evaluate the performance and to understand the unsteady hydrodynamics behind the motion of swimming biomimetic oscillating flexible fins. The results of our research will not only be useful for the design of biomimetic underwater vehicles but will also further the understanding of the fundamental unsteady physics behind the motion of aquatic animals swimming using oscillating appendages. In order to undergo a systematic study of multiple parameters, we use fully-coupled three-dimensional computational simulations. Specifically, we model the oscillating fin as an elastic plate fully submerged in a viscous Newtonian fluid actuated by an imposed sinusoidal base excitation at its leading edge. This simple actuation pattern leads to a spatially asymmetric plate deformation that mimics the flapping motion of a propulsive fish fin. We use our computational tools to first understand the swimming of oscillating plate undergoing free swimming – that is, when the plate cruises forward in a single direction due to a balance between drag and thrust. Here, we identify regimes of high swimming velocity and efficiency. Second, we explore strategies to control the direction of the swimming by making small changes to the leading edge actuation pattern.