In no particular order
A Simplified Test for Pleasure Boat Stability
Zane Ballister
This thesis furthers the efforts made by previous Webb theses to develop a simplified stability test for recreational vessels greater than 20 feet in length. Recreational vessels of this size currently have no regulation requiring stability data be provided to customers, which has led to accidents such as the 2012 sinking of the Kandi Won. This thesis improved the accuracy of the simplified stability test by removing sources of error identified in the data collected in past Webb theses. The error reduction was primarily accomplished through the acquisition and use of improved testing equipment and by refining the testing procedures to reduce the possibility of outside interference. The data collected from these tests were then entered into a database of vessel sallying constants that had been developed over the course of four previous Webb theses. These data were used to create a regression to reliably predict a vessel’s sallying constant.
Mechanical Performance of Stiffened Aluminum Panels as a Function of Weld Parameter, Predicted via Finite Element Analysis
Alex DeMeo and Addison Pope
The marine industry has taken strides to build more efficient and durable ships by making use of alternative materials and fabrication techniques. Being weight-conscientious is one of the most important considerations in creating an efficient ship. Shipbuilders, under the direction of ship owners and operators, have been exploring the substitution of aluminum alloys for steel structural members because of their weight-saving and corrosion-resistant properties. While the material properties are well known for the different alloys, there is limited information on how the material reacts to concentrated heat loads from welding—the most common means for joining metallic materials together. The region of interest is known as the heat-affected zone (HAZ). Representative stiffened aluminum panels were mechanically tested and compared with finite element simulations to investigate the effect of the concentrated heat loads from welding. The test results should improve the understanding of the effects on aluminum alloy material properties when the HAZ is introduced as a result of welding the stiffener to the base plate.
Development of a Simulation and Controls for a Low-Cot, Buoyancy-Driven Underwater Glider
Kohta Erdos and Tsimafei Lazouski
Control systems are critical to the operation of autonomous marine vehicles. In this thesis, project control system implementations will be explored in an underwater buoyancy glider platform created for a previous Webb thesis. The computational capabilities of the glider were enhanced through the addition of an Arduino Uno, a Raspberry Pi, and an Inertial Measurement Unit (IMU). Complementing the hardware upgrades, simulations of the controls were designed in MATLAB to predict system response and in Python for software-in-the-loop testing. These simulations were coupled with the glider controls software that implements the control equations and IMU readings. The glider modifications were tested in Webb Institute’s Robinson Model Basin and the glide cycle controls were verified using software-in-the-loop testing.
The Installation of a Hydrogen Bubble Flow Visualization Apparatus in The Webb Flow Channel
Richard Thill
This thesis serves as both an investigation into and an application of the hydrogen bubble flow visualization method. The method has been effectively used by various universities and research facilities to visualize flow processes around submerged geometries. The hydrogen bubble flow visualization method boasts significant advantages compared to other methods; including, but not limited to, not introducing foreign particles into the flow, producing little flow disturbance, and having the ability to produce time-pulsed bubble sheets. To introduce the capabilities that the method offers into Webb Institute’s research facilities, an apparatus was designed, manufactured, installed, and tested. The apparatus allows for several lengths of thin conducting wires to be either vertically or horizontally spanned across the test section of the Webb flow channel. Lastly, common questions regarding how the method works, as well as its potential limitations, were answered in this thesis, and a user manual was created.
Design of a Passive Shape-Adaptive 470 Class Centerboard
Zachary Doerr and Payne Donaldson
The 470-sailboat class is one of the oldest and most competitive dinghy classes. Although much of the design is strictly determined by class rules, some variability in design and construction of the centerboard is allowed. By making a twisting centerboard, leeway can be reduced, increasing the boat’s upwind performance. This thesis optimizes the laminate schedule of the centerboard to maximize twist when sailing while maintaining sufficient strength to right a capsized boat. Twist is achieved by utilizing the orthotropic properties of fiberglass to produce a bending-torsion coupled response. The foil shaped centerboard is constructed out of foam-cored fiberglass with a polyester matrix. The hydrodynamic pressure is evaluated using the vortex lattice method in XFLR5. The centerboard is treated as a cantilevered beam, and its response is modeled using finite element analysis in SOLIDWORKS.
Enhancing Flutter-Foil Energy Generation
William Calli and Miguel Sanchez
When bluff bodies are submerged in flow, vortices form on alternating sides of the body and cause it to oscillate in a direction perpendicular to that flow. It has been proven that these vibrations, induced in a cylinder, can generate electricity. It has also been proven that using a faired “fat-foil” section can increase the severity of vibrations when compared to a cylinder. The primary objective of this thesis was to build and test a Power Take-Off device to verify that electricity can be generated from vortex induced vibrations. Initial results show that significant power can be taken out and transmitted to a load. Secondary objectives of this thesis are proving that the vibrational increase from a fat-foil section translate to an increase in power generation, and to see if adding restorative forces to the foil’s pitching motion will result in another increase to the power output of the system.
A Simplified Test for Recreational Vessel Stability: Investigating the Sallying Constant
Daryn Cook and Konrad Freischlag
General arrangements developed in AutoCAD are the current marine industry standard for detailing the layout of a ship. However, editing these drawings can be time consuming. In the preliminary design phase, many design decisions and calculations can be made formulaically using regressions, logic, and class society rules. This thesis sought to create a design tool capable of generating a preliminary general arrangement for a bulk carrier given minimal ship parameter user inputs. This tool, written in Visual Basic for Applications in AutoCAD, allows the user to iterate easily through slightly varied parameters then edit the preferred result as desired.
The First Japanese-Built, Western-Style Ships: How Model-Makers Shaped Our View of Late 16th and Early 17th Century Merchant Vessels
Kira Shaw
Although the first Japanese-built, Western-style ships in the early Edo Period are significant in pop culture, not much is actually known about them, especially since the Japanese so rapidly Westernized during the Meiji Era. This thesis evaluates the available information about these vessels and analyzes the validity of the models made of them. It also identifies important considerations for viewing models of historical ships in general. It was concluded that historians and naval architects play key but distinct roles in our perception of historical vessels. The models of the first Japanese-built, Western-style ships are better treated as potential interpretations as opposed to accurate replicas. A recommendation for future work could be to study models of vessels from a different period. In general, there is a place for more theses that recognize how much the humanities and engineering are intertwined.
Numerical Analysis of Flow around a Biomimetic Undulated Foil Shape with Fluid Structure Interaction
Kenna Reed and Kadi Zheng
This thesis analyzes the highly unsteady separated vortical wake region behind a biomimetic inspired foil shape. The inspiration for the foil shape comes from the harbor seal whisker, which is an undulated elliptical extrusion. The analysis was performed using the multi-physics commercial simulation software, STAR-CCM+. This solver was used to perform a fluid structure interaction (FSI) analysis to better represent the compliance of a whisker in a free stream. The results of the FSI analysis were compared to rigid test cases and the base geometry cases which included an extruded cylinder and extruded ellipse. Changing different geometric parameters altered the wake region significantly and changed the amplitude and frequency of the vortex-induced vibrations. Recommendations for future work include testing a wider range of the geometric parameters and changing the geometry to include a tapered end and a sweep angle.
USCGC Lilac Feasibility Study: Electrical Renovation of a Historic Lighthouse Tender for Passenger Service
Joseph LaPlace and Max Mah
The USCGC Lilac is a 1933-built lighthouse tender currently operated by the Lilac Preservation Project as a museum ship with an aspiration of operating as a passenger vessel. This thesis is a feasibility study for the overhaul of Lilac’s electrical system to meet current passenger vessel standards, which, for the purposes of this thesis, are outlined in 46 CFR Subchapter T. It also aims to develop a specific plan for power generation while maintaining the historical integrity of the vessel. The development of an electric plant load analysis, a one-line diagram, and a delineation for emergency power and transformers were all completed for this thesis.
Computational Fluid Dynamic Analysis of Membrane Tank Pressure Distribution as a Result of LNG Sloshing
Jack Otto
LNG membrane tanks have become the dominant method of transportation in LNGCs. However, there have been stringent operation limitations on load states. These limitations result from tank sloshing impact pressures, which can potentially cause damage and loss of containment. Previous research into the LNG sloshing issue has determined that problems arise when the excitation frequency matches the resonant frequency of the fluid rather than when there is significant amplitude excitation. To further investigate the effect of excitation frequency on the LNG sloshing issue, a six-degree of freedom mathematical model was developed to determine pressure profiles resonant and near-resonant pressure profiles in roll. The resulting pressure profiles were compared to DNV guidelines for membrane tanks for acceptable pressures at varying heights.
Developing and Strength Testing a Natural Fiber Composite for Yacht Construction
Evan Spalding
The yacht industry predominantly uses fiberglass composites for construction because of their superior strength, lightweight properties, and resistance to corrosion. However, the environmental impact at the end-of-life of these materials is significant, primarily because they cannot be recycled and end up in landfills. This thesis proposes an alternative solution by developing a sustainable natural fiber composite (NFC) that could potentially replace fiberglass in yacht manufacturing. NFCs utilize renewable fibers such as hemp, flax, and jute, which not only reduce the environmental footprint during production but also offer the possibility of composting after the yacht’s life cycle. Additionally, this research explores various matrix materials used in NFCs to determine the most effective combination that maintains the necessary mechanical properties for maritime use. The thesis aims to demonstrate that NFCs can meet the requirements of yacht construction in terms of durability and strength through rigorous simulation and real-world testing.
Concept Design Tool: Automation of EPLA and One-Line Diagram Generation
Evan Kawabata
Advancements in modern computational techniques and algorithms could significantly aid designers in the concept design stage for a ship. Traditionally, designers manually enter equipment electrical data into a spreadsheet to provide an early estimate of generator loading. This spreadsheet is then the foundation for future electrical calculations and drawings. Automating the generation of an electric plant load analysis will allow engineers to focus on more meaningful design decisions or explore more design iterations. This thesis developed a software design tool capable of generating an electrical plant load analysis with minimal user inputs. This tool is intended to be used with another created by Hunt and Koziol (Webb 2021) for the generation of a one-line diagram. Limited to double-ended ferries, this design tool is able to predict electrical loads with reasonable accuracy as vessel parameters change.
Port Infrastructure Feasibility and Risk Assessment for a Modularized Hydrogen Fuel Cell Ferry
Margo Bourn
The port infrastructure feasibility was assessed for the modularized hydrogen fuel cell ferry conversion design of the Molinari Class Ferry of the Staten Island Ferry developed by Allen and Lytle (2023). The spatial feasibility of on-site electrolyzer production of hydrogen was evaluated for the available space at the ferry bunkering terminal. The feasibility study found that hydrogen delivery by truck and by barge from a secondary hydrogen production facility is feasible. The selected port infrastructure, barge delivery of hydrogen, underwent a quantitative risk assessment. The risk assessment involves hazard identification of the design followed by release event modeling of representative failure cases. Jet fire consequence modeling occurred in the Areal Location of Hazardous Atmospheres (ALOHA) software program. The implementation of port infrastructure with swappable hydrogen containers at the St. George Ferry Terminal results in intolerable levels of risk without risk mitigation measures. Additionally, the dispersion and flammability properties of hydrogen indicate that there will be catastrophic consequences in the event of a failure in the port infrastructure system design considered. To enable crane bunkering of swappable hydrogen containers at the port, additional risk mitigation measures must be implemented.
A Large Database Study On The Evolution And Performance Of Sailing Yachts
Lisandro Nicoletti