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Ocean Engineering

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Full-Text Articles in Mechanical Engineering

Development Of A New Lagrangian Float For Studying Coastal Marine Ecosystems, Alex Schwithal, Chris Roman Jan 2013

Development Of A New Lagrangian Float For Studying Coastal Marine Ecosystems, Alex Schwithal, Chris Roman

Christopher N. Roman

This paper presents an overview and initial testing results for a shallow water Lagrangian float designed to operate in coastal settings. The presented effort addresses the two main characteristics of the shallow coastal environment that preclude the direct of use of many successfully deep water floats, namely the higher variation of water densities near the coast compared with the open ocean and the highly varied bathymetry. Our idea is to develop a high capacity dynamic auto-ballasting system that is able to compensate for the expected seawater density variation over a broad range of water temperatures and salinities while using measurements …


Concept Tests For A New Wire Flying Vehicle Designed To Achieve High Horizontal Resolution Profiling In Deep Water, Chris Roman, Dave Hebert Dec 2012

Concept Tests For A New Wire Flying Vehicle Designed To Achieve High Horizontal Resolution Profiling In Deep Water, Chris Roman, Dave Hebert

Christopher N. Roman

Efficiently profiling the water column to achieve both high vertical and horizontal resolution from a moving vessel in deep water is difficult. Current solutions, such as CTD tow-yos, moving vessel profilers, and undulating tow bodies, are limited by ship speed or water depth. As a consequence, it is difficult to obtain oceanographic sections with sufficient resolution to identify many relevant scales over the deeper sections of the water column. This paper presents a new concept for a profiling vehicle that slides up and down a towed wire in a controlled manner using the lift created by wing foils. The wings …


The Optimal Control Of A Flexible Hull Robotic Undersea Vehicle Propelled By An Oscillating Foil, David Barrett, Mark Grosenbaugh, Michael Triantafyllou Jul 2012

The Optimal Control Of A Flexible Hull Robotic Undersea Vehicle Propelled By An Oscillating Foil, David Barrett, Mark Grosenbaugh, Michael Triantafyllou

David Barrett

Determining the optimal swimming motion for a flexible hull robotic undersea vehicle propelled by an oscillating foil is an acutely complex problem involving the vehicle's body kinematics and the hydrodynamics of the surrounding water. The overall intractability of the hydrodynamics of a flexible body precludes a purely analytical solution. The immense size of the experimental variable space prevents a purely empirical one. In order to overcome both difficulties, we have developed a self-optimizing motion controller based on a genetic algorithm. This controller effectively uses evolutionary principles to exponentially optimize swimming performance.


Control System Performance And Efficiency For A Mid-Depth Lagrangian Profiling Float, B. Mcgilvray, C. Roman May 2010

Control System Performance And Efficiency For A Mid-Depth Lagrangian Profiling Float, B. Mcgilvray, C. Roman

Christopher N. Roman

This paper presents the development of a new mid-depth Lagrangian profiling float with a primary emphasis on the control system performance and efficiency. While deep water floats have demonstrated much success in open ocean environments, many are not suited for the additional challenges associated with coastal regions. To study these regions, which are often subject to varying bathymetry within the operating range and higher variations in water density, a more advanced system is required. This new design utilizes pressure and altitude feedback to drive a high volume auto-ballasting system (ABS). The main operating modes of this float include step inputs …