George V. Lauder,
Henry Bryant Bigelow Professor
Professor of Organismic and Evolutionary Biology
Tuesday, February 28, 10-11:30 am
ICTAS building on Stanger Street, Room 310
There are over 28,000 species of fishes, and a key feature of this remarkable evolutionary diversity is the variety of propulsive systems used by fishes for swimming in the aquatic environment. Fishes have numerous control surfaces which act to transfer momentum to the surrounding fluid. In this presentation I will discuss the results of recent experimental kinematic and hydrodynamic studies of fish locomotor function, and the implications for construction of robotic models of fishes. Recent high-resolution video analyses of fish fin movements during locomotion show that fins undergo much greater deformations than previously suspected and fish fins possess an clever active surface control mechanism. Fish body and fin motion results in the formation of vortex rings of various conformations, and quantification of vortex rings shed into the wake by freely-swimming fishes has proven to be useful for understanding the mechanisms of propulsion. Experimental analyses of propulsion in freely-swimming fishes have led to the development of a variety of self-propelling robotic models. Data from these devices will be presented and discussed in terms of the utility of using robotic models for understanding fish locomotor dynamics, and for studying the function of specialized fish surface structures like shark skin.