Affiliations: Department of Ocean Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, USA
Abstract: Recent interest in the application of fish-like propulsion
mechanisms to practical engineering systems has led to the development of a
three-dimensional numerical method to enable the study of the fluid dynamics
associated with flexible-body swimming. Visualization of the near-body and
near-wake flow processes has elucidated unique flow manipulation capabilities
utilized by the fish, associated with the controlled production and release of
body-generated vorticity. In addition, efficient actuation of flow into the
oscillating tail allows for energy recovery by the tail from flow perturbations
initiated by the upstream flexible-body motions for improved efficiency. In
this work, we highlight some of these processes through visualization of the
unsteady flow patterns, whose three-dimensionality is more complex than linear
theory would suggest. We then compare these results to experimental data of
fish swimming dynamics. These comparisons reinforce the applicability of the
simulation method as a visualization tool for the study of the hydrodynamic
mechanisms of fish-like swimming motions.