Proceedings of Symposium on Autonomous Underwater Vehicle Technology
Page 1. The Optimal Control of a Flexible Hull Robotic Undersea Vehicle Propelled by an Oscillati... more Page 1. The Optimal Control of a Flexible Hull Robotic Undersea Vehicle Propelled by an Oscillating Foil David Barrett Mark Grosenbaugh Michael Triantafyllou Dept. of Ocean Engineering 77 Mass Ave. Rm 48-015 Cambridge, Ma. 02139 Dept. ...
Thrust-producing harmonically oscillating foils are studied through force and power measurements,... more Thrust-producing harmonically oscillating foils are studied through force and power measurements, as well as visualization data, to classify the principal characteristics of the flow around and in the wake of the foil. Visualization data are obtained using digital particle image velocimetry at Reynolds number 1100, and force and power data are measured at Reynolds number 40 000. The experimental results are compared with theoretical predictions of linear and nonlinear inviscid theory and it is found that agreement between theory and experiment is good over a certain parametric range, when the wake consists of an array of alternating vortices and either very weak or no leading-edge vortices form. High propulsive efficiency, as high as 87%, is measured experimentally under conditions of optimal wake formation. Visualization results elucidate the basic mechanisms involved and show that conditions of high efficiency are associated with the formation on alternating sides of the foil of a...
Underwater vehicles have many uses in civilian as well as military marine operations. Their appli... more Underwater vehicles have many uses in civilian as well as military marine operations. Their applications range from maintenance and inspection on oil rigs to underwater salvage operations, and from scraping barnacles off the hulls of ships to searching a hostile bay for mines. For such vehicles to carry out their tasks it is advantageous to have high propulsive efficiencies. Efficiency for an underwater vehicle is measured by recording the amount of energy required to pull the vehicle through the water at a certain velocity and comparing that to the energy which the vehicle must expend to propel itself at the same velocity. Propellers are the primary conventional mechanism for water-based propulsion. The efficiency of a propeller scales up with specific load. This means that while a propeller works well on a vehicle with large available diameter, like a submarine, it has a rather limited efficiency for smaller autonomous vehicles where propellers must fit in cramped spaces. Addition...
Proceedings of Symposium on Autonomous Underwater Vehicle Technology
Page 1. The Optimal Control of a Flexible Hull Robotic Undersea Vehicle Propelled by an Oscillati... more Page 1. The Optimal Control of a Flexible Hull Robotic Undersea Vehicle Propelled by an Oscillating Foil David Barrett Mark Grosenbaugh Michael Triantafyllou Dept. of Ocean Engineering 77 Mass Ave. Rm 48-015 Cambridge, Ma. 02139 Dept. ...
Thrust-producing harmonically oscillating foils are studied through force and power measurements,... more Thrust-producing harmonically oscillating foils are studied through force and power measurements, as well as visualization data, to classify the principal characteristics of the flow around and in the wake of the foil. Visualization data are obtained using digital particle image velocimetry at Reynolds number 1100, and force and power data are measured at Reynolds number 40 000. The experimental results are compared with theoretical predictions of linear and nonlinear inviscid theory and it is found that agreement between theory and experiment is good over a certain parametric range, when the wake consists of an array of alternating vortices and either very weak or no leading-edge vortices form. High propulsive efficiency, as high as 87%, is measured experimentally under conditions of optimal wake formation. Visualization results elucidate the basic mechanisms involved and show that conditions of high efficiency are associated with the formation on alternating sides of the foil of a...
Underwater vehicles have many uses in civilian as well as military marine operations. Their appli... more Underwater vehicles have many uses in civilian as well as military marine operations. Their applications range from maintenance and inspection on oil rigs to underwater salvage operations, and from scraping barnacles off the hulls of ships to searching a hostile bay for mines. For such vehicles to carry out their tasks it is advantageous to have high propulsive efficiencies. Efficiency for an underwater vehicle is measured by recording the amount of energy required to pull the vehicle through the water at a certain velocity and comparing that to the energy which the vehicle must expend to propel itself at the same velocity. Propellers are the primary conventional mechanism for water-based propulsion. The efficiency of a propeller scales up with specific load. This means that while a propeller works well on a vehicle with large available diameter, like a submarine, it has a rather limited efficiency for smaller autonomous vehicles where propellers must fit in cramped spaces. Addition...
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