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Theses/Dissertations

2020

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Articles 1 - 18 of 18

Full-Text Articles in Ocean Engineering

Deepsea Coral Sample Container, Sara Passantino, Andrew Noble, Casey Smith, Thomas Smith Dec 2020

Deepsea Coral Sample Container, Sara Passantino, Andrew Noble, Casey Smith, Thomas Smith

Mechanical Engineering

In order to better understand the health of our oceans and the species that inhabit them, scientists often collect samples for later analysis onshore. The demanding deep-sea environment makes this collection process a challenging engineering task. Samples must first be located, then removed from the seafloor and stored for transportation to the surface. The performance of the engineered solutions that complete each of these tasks is critical in allowing marine scientists to maximize the insight obtained from their expeditions. Marine Applied Research and Exploration (MARE) is an organization that performs such collection of organisms with the help of remotely operated …


Optimal Onboard Renewable Energy Charging Method To Improve Micro-Autonomous Underwater Vehicle Deployment Life, Brooklynn Dawn Byford Dec 2020

Optimal Onboard Renewable Energy Charging Method To Improve Micro-Autonomous Underwater Vehicle Deployment Life, Brooklynn Dawn Byford

Theses and Dissertations

This study is an investigation of various methods for recharging a micro autonomous underwater vehicle (μAUV) onboard using renewable energy sources while deployed at sea. The goal of this project is to determine the optimal onboard renewable energy design method to be used to prolong the deployment life of a μAUV. This project specifically targeted vehicles specifications and designs similar to the Riptide Autonomous Solutions’ μAUV[1], which was used for this study. Concluding results are based on the following factors: power generation versus time, structural integrity, and design complexity. The three design method categories investigated are as follows: solar energy, …


Finite Element Method For Assessment Of Air Cushion Skirt Performance, Thomas Arthur Lipscomb Dec 2020

Finite Element Method For Assessment Of Air Cushion Skirt Performance, Thomas Arthur Lipscomb

Theses and Dissertations

The objective of this thesis is to create a method of simulating the performance of new materials for use in air cushion vehicle skirts. These systems currently exhibit unacceptable design lifetimes to be considered for widespread adoption, except in specific applications such a military or rapid transport, where high cost is not an obstacle. This project also focuses on using a new high strain to failure resin system that has recently been developed, in combination with high performance reinforcing fibers, to increase the lifespan of the skirt systems. Using industry-standard finite element modelling (FEM) software, a 3d model of the …


Extreme Response Analysis Of A Site-Specific Offshore Wind Turbine And Offshore Wind Farm Layout Optimization, Xiaosen Xu Dec 2020

Extreme Response Analysis Of A Site-Specific Offshore Wind Turbine And Offshore Wind Farm Layout Optimization, Xiaosen Xu

Theses and Dissertations

Offshore floating wind turbines have been developed in deep water where bottom-fixed offshore wind turbines are cost-prohibitive. Gulf of Maine has one of the greatest potential wind energy on the east coast. A detailed analysis of metocean data is essential for the dynamic simulation of the floating offshore wind turbine and the offshore wind farm layout optimization. Wave scatter diagram represents the joint probability of significant wave height and peak periods. In the wind energy industry, turbulence intensity is defined as the standard deviation of the horizontal wind speed divided by the average wind speed over certain time period. Uniform …


Simulation Of A Unit Injector For Ammonia Injection In A Compression Ignition Engine, Mohammed Aziem Rujub Nov 2020

Simulation Of A Unit Injector For Ammonia Injection In A Compression Ignition Engine, Mohammed Aziem Rujub

World Maritime University Dissertations

No abstract provided.


Deep-Sea Water Collector, Chandler Jones, Jenny Verheul, Michael Di Giorgio Nov 2020

Deep-Sea Water Collector, Chandler Jones, Jenny Verheul, Michael Di Giorgio

Mechanical Engineering

Properties such as nutrients, DNA, pH levels, and primary productivity are difficult to measure onboard an Underwater Remotely Operated Vehicle (UROV) as mobile submarine sensors are highly expensive and conventional water capture devices are too large to be equipped. However, these properties provide an integral view into our oceans, the species that inhabit them, and our influence on the environment. Collected samples of seawater taken back to labs allow researchers to see a clearer picture of ecosystems’ inhabitants and lifecycle with the analysis of Environmental DNA (eDNA) among many other properties. The scope of this project is to design a …


Resonant Triad Interactions In One And Two-Layer Systems, Malik Chabane Aug 2020

Resonant Triad Interactions In One And Two-Layer Systems, Malik Chabane

Dissertations

This dissertation is a study of the weakly nonlinear resonant interactions of a triad of gravity-capillary waves in systems of one and two fluid layers of arbitrary depth, in one and two-dimentions. For one-layer systems, resonant triad interactions of gravity-capillary waves are considered and a region where resonant triads can be always found is identified, in the two-dimensional wavevector angles-space. Then a description of the variations of resonant wavenumbers and wave frequencies over the resonance region is given. The amplitude equations correct to second order in wave slope are used to investigate special resonant triads that, providing their initial amplitude …


Wave Attenuation Capacity Of Suspended Aquaculture Structures With Sugar Kelp And Mussels, Longhuan Zhu Aug 2020

Wave Attenuation Capacity Of Suspended Aquaculture Structures With Sugar Kelp And Mussels, Longhuan Zhu

Electronic Theses and Dissertations

Large aquaculture systems may have the potential to damp wave energy for coastal protection. The performance of these systems are influenced by the dynamics of components such as flexible kelp blades and mussel droppers. In this thesis, the dynamics of kelp blades and mussel droppers were investigated with a consistent-mass cable model with focus on understanding the asymmetric motion of kelp blades. The results showed the asymmetric blade motion in symmetric waves is caused by the spatial asymmetry of the encountered wave orbital velocities due to blade displacements and the asymmetric action on the blade by vertical wave orbital velocities. …


Experimental Investigation Into The Boundary Layer Of A Robotic Anguilliform Propulsor, Jonathan R. Eastridge Aug 2020

Experimental Investigation Into The Boundary Layer Of A Robotic Anguilliform Propulsor, Jonathan R. Eastridge

University of New Orleans Theses and Dissertations

Boundary layer information local to three longitudinal positions has been characterized for a 130 cm long biomimetic self-propulsor known as NEELBOT-1.1 that swims with undulatory anguilliform-like motions, via analysis of stereo particle image velocimetry (PIV) measurements for key moments in the undulation cycle and for numerous combinations of swimming conditions and motion parameters, ideal and non-ideal. No obvious turbulent flow structures or indications of boundary layer separation were observed at nonzero advance speeds, and skin friction coefficients were subsequently estimated for magnitude relative to the dynamic pressure associated with operation at the design swimming speed of Uo = 0.25 …


Alternative Material Selection For Oyster Restoration With An Emphasis On Living Docks, Bridgette Soucy Aug 2020

Alternative Material Selection For Oyster Restoration With An Emphasis On Living Docks, Bridgette Soucy

Theses and Dissertations

Oyster restoration efforts, including Living Shoreline and Living Dock projects, utilize aquaculture-grade plastic oyster mats to mitigate the decline of benthic communities. Aquaculture-grade plastic are known for strength, durability, and resilience to degradation in seawater. Over time, plastics break into microscopic segments commonly referred to as microplastics. Microplastics represent a major concern as marine organisms mistake the small particles for food. Plastics bioaccumulate in marine species, which impacts the marine food web and humans. In order to reduce further negative anthropogenic impacts, natural fibers and nature-inspired concrete mixtures were utilized across a series of experiments in order to determine an …


Modular Cable Buoy, James J. Marinas, Gabriela Vargas, Anthony Catello, Joseph Heald Jun 2020

Modular Cable Buoy, James J. Marinas, Gabriela Vargas, Anthony Catello, Joseph Heald

Mechanical Engineering

Cable terminations are often the least reliable and most expensive components of a maritime system. These cables are suspended in water by a buoy to reduce wear at the terminations. The Naval Information Warfare Center requires a modular auxiliary float with tunable buoyancy that can be placed along such cable. Our system must be able to be deployed, adjusted, and retrieved quickly and easily during operational use. This report focuses on our team’s final design concept and includes all analysis to justify our design direction along with safety, maintenance, and repair considerations. The report further elaborates on cost analysis, manufacture …


Compound Flooding In Coastal Areas Emanating From Inland And Offshore Events, Hamed Behzad Koochaksaraii May 2020

Compound Flooding In Coastal Areas Emanating From Inland And Offshore Events, Hamed Behzad Koochaksaraii

Dissertations

The vulnerability of urban populations to natural hazards and climate change is a major theme in many reports on coastal cities with flooding ranking highly among the climate change concerns. Flooding could occur as a result of runoff for inland rainfall that accumulates at the mouth of the estuary to the sea or it could occur due to a storm surge emanating from the ocean. The techniques for modeling the flooding from these events are very different, as they were developed in different scientific fields: hydrology and hydraulic engineering for inland rainfall versus coastal oceanography and coastal engineering for offshore …


Living Docks: Structural Implications And Determination Of Force Coefficients Of Oyster Mats On Dock Pilings In The Indian River Lagoon, Ryan Christiansen May 2020

Living Docks: Structural Implications And Determination Of Force Coefficients Of Oyster Mats On Dock Pilings In The Indian River Lagoon, Ryan Christiansen

Theses and Dissertations

Brevard County, Florida, is facing rapid population growth and increased pollution entering the Indian River Lagoon (IRL), impairing water quality and damaging the ecosystem. This is problematic not only for public health and environmental stability, but also for the economy. The Living Docks initiative was created to combat environmental degrade in the lagoon and restore natural functions back to the ecosystem. With increased urbanization along coastal systems, there is opportunity for new forms of ecological engineering such as Living Docks, which attaches oyster mats to dock pilings as a means to promote the growth of filter feeding organisms. It is …


Design Of An Environmentally Responsive Grooming Tool To Aid In Underwater Navigation, Bruce Huntress Walker Iii May 2020

Design Of An Environmentally Responsive Grooming Tool To Aid In Underwater Navigation, Bruce Huntress Walker Iii

Theses and Dissertations

Underwater hull grooming is a proactive approach to ship hull husbandry. It has been defined as the frequent and gentle wiping of a ship hull coating to maintain it free of fouling. One of the challenges to implementing a grooming schedule is the control and navigation of the devices over the surface of the hull. This thesis presents prior research that has developed self-attaching rotating brushes as an effective method to groom fouling control coatings and the results from several years of implementation in the marine environment. The hypothesis of this thesis is that the condition of the ship hull …


Shallow Water Seafloor Geodesy: Gps On An Anchored Spar Buoy, Surui Xie Feb 2020

Shallow Water Seafloor Geodesy: Gps On An Anchored Spar Buoy, Surui Xie

USF Tampa Graduate Theses and Dissertations

Measuring seafloor motion in shallow coastal water is challenging due to strong and highly variable oceanographic effects. Such measurements are potentially useful for monitoring near-shore coastal subsidence, subsidence due to petroleum withdrawal, strain accumulation/release processes in marine shelves and submerged volcanoes, and certain fresh water applications, such as volcano deformation in caldera-hosted lakes. I participated in a project to develop a seafloor geodetic system for this environment based on an anchored spar buoy topped by high precision GPS. Orientation of the buoy is measured using a digital compass that provides heading, pitch, and roll information. The combined orientation and GPS …


Optimization Of Shape And Control Of Linear And Nonlinear Wave Energy Converters, Jiajun Song Jan 2020

Optimization Of Shape And Control Of Linear And Nonlinear Wave Energy Converters, Jiajun Song

Dissertations, Master's Theses and Master's Reports

In this dissertation, we address the optimal control and shape optimization of Wave Energy Converters. The wave energy converters considered in this study are the single-body heaving wave energy converters, and the two-body heaving wave energy converters. Different types of wave energy converters are modeled mathematically, and different optimal controls are developed for them. The concept of shape optimization is introduced in this dissertation; the goal is to leverage nonlinear hydrodynamic forces which are dependent on the buoy shape. In this dissertation, shape optimization is carried out and its impact on energy extraction is investigated. In all the studies conducted …


A Neural Network Approach To Estimate Buoy Mooring Line Sensor Deflection, Tom Price Jan 2020

A Neural Network Approach To Estimate Buoy Mooring Line Sensor Deflection, Tom Price

Dissertations, Master's Theses and Master's Reports

Instrumented moorings are often used to measure characteristics, such as temperature and current, over the water column. However, the moorings deflect from the effects of currents and waves, which could lead to innacurate measurements. In this work, a computationally efficient method to compensate for mooring sensor position errors is developed. The two-step process first uses a hydrodynamic model of the buoy and mooring line system to create estimated mooring line deflections in a steady current. A neural network model is trained to approximate the hydrodynamic model’s mooring line displacement given the spatial location of the buoy and current profile measurements. …


Development Of Horizontal Axis Hydrokinetic Turbine Using Experimental And Numerical Approaches, Abdulaziz Abutunis Jan 2020

Development Of Horizontal Axis Hydrokinetic Turbine Using Experimental And Numerical Approaches, Abdulaziz Abutunis

Doctoral Dissertations

“Hydrokinetic energy conversion systems (HECSs) are emerging as viable solutions for harnessing the kinetic energy in river streams and tidal currents due to their low operating head and flexible mobility. This study is focused on the experimental and numerical aspects of developing an axial HECS for applications with low head ranges and limited operational space. In Part I, blade element momentum (BEM) and neural network (NN) models were developed and coupled to overcome the BEM’s inherent convergence issues which hinder the blade design process. The NNs were also used as a multivariate interpolation tool to estimate the blade hydrodynamic characteristics …