Biomechanics and Energetics of Locomotion in Rigid-Bodied Fishes
Abstract
The tropical marine fishes of the family Ostraciidae (boxfishes, trunkfishes, cowfishes) are the best available living models for engineered autonomous underwater vehicles (AUVs). The forward 2/3 - 3/4 of their bodies are encased in rigid bony carapaces that prevent their bending any parts of their bodies except the bases of their tails. As a result they swim entirely by means of movements of their five fins. We have studied four different species, each having a carapace of a different shape and structure. Field and laboratory studies show that they are all surprisingly fast and maneuverable, with considerable endurance. They swim through turbulent environments with excellent control a%d dynamic stability. They do this by using a series of different gaits (different patterns of coordinated and controlled fin movements). Two important results of their use of gaits are that: (1) they produce dynamic stability by continuously balancing turning force moments generated by the movements of their fins; and (2) they control the energy costs of swimming to unusually large extents. The morphological details of the structures of their carapaces are also important in producing these results. Flow visualization studies show that the carapaces generate vortical flows in specific locations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 14, 2002
- Accession Number
- ADA403152
Entities
People
- Malcom S. Gordon
Organizations
- University of California, Los Angeles