Biomaterial Database

Force scaling and efficiency of elongated median fin propulsion. 2022

Mohammad I Uddin, and Gonzalo A Garcia, and Oscar M Curet

Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, FL, United States of America.

Several fishes swim by undulating a thin and elongated median fin while the body is mostly kept straight, allowing them to perform forward and directional maneuvers. We used a robotic vessel with similar fin propulsion to determine the thrust scaling and efficiency. Using precise force and swimming kinematics measurements with the robotic vessel, the thrust generated by the undulating fin was found to scale with the square of the relative velocity between the free streaming flow and the wave speed. A hydrodynamic efficiency is presented based on propulsive force measurements and modelling of the power required to oscillate the fin laterally. It was found that the propulsive efficiency has a broadly high performance versus swimming speed, with a maximum efficiency of 75%. An expression to calculate the swimming speed over wave speed was found to depend on two parameters:Ap/Ae(ratio between body frontal area to fin swept area) andCD/C(ratio of body drag to fin thrust coefficient). The models used to calculate propulsive force and free-swimming speed were compared with experimental results. The broader impacts of these results are discussed in relation to morphology and the function of undulating fin swimmers. In particular, we suggest that the ratio of fin and body height found in natural swimmers could be due to a trade-off between swimming efficiency and swimming speed.

UI	MeSH Term	Description	Entries
D005399	Fishes	A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001696	Biomechanical Phenomena	The properties, processes, and behavior of biological systems under the action of mechanical forces.	Biomechanics,Kinematics,Biomechanic Phenomena,Mechanobiological Phenomena,Biomechanic,Biomechanic Phenomenas,Phenomena, Biomechanic,Phenomena, Biomechanical,Phenomena, Mechanobiological,Phenomenas, Biomechanic
D012371	Robotics	The application of electronic, computerized control systems to mechanical devices designed to perform human functions. Formerly restricted to industry, but nowadays applied to artificial organs controlled by bionic (bioelectronic) devices, like automated insulin pumps and other prostheses.	Companion Robots,Humanoid Robots,Remote Operations (Robotics),Social Robots,Socially Assistive Robots,Telerobotics,Soft Robotics,Assistive Robot, Socially,Companion Robot,Humanoid Robot,Operation, Remote (Robotics),Operations, Remote (Robotics),Remote Operation (Robotics),Robot, Companion,Robot, Humanoid,Robot, Social,Robot, Socially Assistive,Robotic, Soft,Social Robot,Socially Assistive Robot,Soft Robotic
D013550	Swimming	An activity in which the body is propelled through water by specific movement of the arms and/or the legs. Swimming as propulsion through water by the movement of limbs, tail, or fins of animals is often studied as a form of PHYSICAL EXERTION or endurance.
D057446	Hydrodynamics	The motion of fluids, especially noncompressible liquids, under the influence of internal and external forces.	Fluid Dynamics,Dynamic, Fluid,Dynamics, Fluid,Fluid Dynamic,Hydrodynamic