STUDENT PAPERS NIGHTAGENDA5:00 PM – Social Hour
6:00 PM – Dinner
7:00 PM – Technical Session
PRICING$75.00 – Non-members and Guests
$50.00 – Members
$20.00 – Students
STUDENT PRESENTATION TOPICS INCLUDE:
Connor McGowan, P.E, USMMATitle: “Active Magnetic Bearing Systems for Shipboard Applications”
As long as there have been motorized vessels there has been a need for bearings. Bearings are fundamental to the operation of various types of machinery and systems onboard a vessel, offering unconstrained motion in a particular degree of freedom while limiting others. Principle directions of motion have included both the familiar rotational in engines, turbines, and motors as well as linear motion associated with cross heads, slides, and linear actuators. Traditionally, bearings aboard vessels have fallen into categories of sliding, rolling element, and hydrodynamic, possessing commonality of force transmission through a physical medium.
Unlike the aforementioned contact and fluid bearings, Active Magnetic Bearings (AMB) are a class of bearings that, as the name implies, utilize magnetic force to support a load allowing for nearly frictionless operation. AMBs incorporate an element of active control, opening up a wide range of additional possibilities as compared to their mechanical contact counterparts. Some additional possibilities readily implemented on AMB systems including variable stiffness and damping, larger operating speed capability, and even dynamic vibration suppression.
This paper examines the basic concepts involved in active magnetic bearing design, so as to, implement a computer based simulation of an AMB system and evaluate its performance. The major concepts or rotordynamics required to model a rotor are investigated and a finite element model simulation constructed. The basics of electromagnet design and principle equations are examined for use in a simulation. Linearization methods for the force-current relationships are evaluated. Control of the amplifier driving the electromagnet is considered for the high inductive characteristics of the electromagnet. A non-centralized PID controller system is designed and implemented using the principles and models developed for the rotor, electromagnet, and amplifier. The PID controller is then tuned and performance evaluated for shipboard type conditions. Finally, modern centralized controller design is examined and the advantages and disadvantages contrasted with the classical PID type controller.
The results of the simulation indicated that a classical controller would be suitable for controlling machinery supported by AMBs in a shipboard environment. The simplicity and ease of tuning and implemented a PID controllers for this style system in a shipboard environment represented a major advantage of the controller.
MIDN Annie Bladow 1/C, USMMATitle: “Maritime Applications of Wire Arc Additive Manufacturing”
Additive Manufacturing (AM) is a process where metal components are created by continually adding material one layer at a time. Several benefits of “additive” manufacturing versus traditional “subtractive” machining processes include a reduction of material waste, ease of producing complex parts by reducing the amount of production steps, and the reduction of manufacturing time. Metal based AM (also called metal 3D printing) technologies have been developing over the past three decades to simplify the manufacturing process of metal parts and assemblies. The aerospace, medical, and marine industries have begun to utilize AM technologies in production. The purpose of this study is to discuss and analyze the current AM methods and how the technologies can be applied for use in the marine industry. The Wire Arc Additive Manufacturing (WAAM) process which uses Metal Inert Gas (MIG) welding, is used to analyze the potential application of WAAM for maritime utilization. This report shows how the flexural strength of welded plates increases with different amounts of metal additive reinforcement. A standard three-point bending test was conducted to determine the difference in flexural yield strength and discuss observed material behavior. Finally, it is discussed that AM processes, such as WAAM, are still being developed but their potential in the maritime industry is clear.
Ben Lilly, Senior, Webb InstituteTitle: “Analysis and Optimization of Power Plant Selection for Harbor Tugboats”
There is a growing demand in the marine industry to reduce emissions through the implementation of improved and emerging power plant configurations and technologies. Reducing emissions produced by a diesel engine requires optimizing the engine’s load profile, avoiding low engine loads to maintain efficient operation. This is particularly challenging in harbor tugboats as they spend most of their time operating at low propulsive loads by nature of their operational profile. Therefore, a unique opportunity exists for harbor tugboat designs to maximize the potential of alternative fuels, batteries, and hybrid propulsion solutions to reduce emissions. These technologies have higher capital costs than conventional power plants but can also reduce the operating expenses of a vessel by reducing fuel consumption. A number of different power plants for a harbor tugboat are analyzed to determine their fuel consumption and emissions. The differences in total life cycle cost are then compared to evaluate their economic viability.
Calder Hartigan, Senior, Webb InstituteTitle: “A Numerical Investigation into Unsteady Surge Effects in Slender Hulls”
The unsteady effects of oscillating harmonic surge motions acting on a Wigley hull in three degrees of freedom were investigated numerically using fully viscous CFD simulations. Tests were conducted in a three-dimensional computational domain with the Wigley hull free in sinkage and trim with a forced surge velocity. The frequency and amplitude of the forced surge were varied independently to validate with the experimental data of Doctors et al. (2010). The motivation for this work was to assess the utility of modern URANS CFD codes for modeling the resistance of rowing shells. Initial steady-speed tests were validated using experimental data to create a baseline estimate of the accuracy that could reasonably be expected in the surging tests. Domain, mesh, and timestep convergence were investigated for both steady and unsteady tests. Steady-speed results show reasonable agreement with experimental data and follow the expected trends across the range of speeds expected in the surging tests. Unsteady tests show reduced accuracy, with the trends indicating that the RANS CFD codes could be a valuable tool for modeling rowing shell resistance if further simulation refinement were done with a focus on verification and validation.
Evan Headley and Aidan McEnroe, Naval Engineering Seniors, Stevens Institute of Technology
Title: Promoting Electric Propulsion for Small Craft” Design of an Autonomous Vessel for the ASNE Competition
An inter-disciplinary team of ten undergraduate engineering students has been working on an electric, unmanned, autonomous, high-speed vessel for the Promoting Electric Propulsion (PEP) for Small Craft competition being conducted by the American Society of Naval Engineers. The naval engineering sub team has focused on the design of a high-speed planing platform, the mechanical engineering sub team researched propulsion and cooling systems, while the computer science sub team designed the control and autonomous navigation systems. Following an iterative hull design process, the naval engineering sub team settled on a variable deadrise planing hull with a high length to beam ratio. A set of three water jets were selected to provide necessary propulsive power. Twin Arduinos for the control system and a Raspberry Pi based system to handle the autonomous navigation and power management have been developed. The hull was CNC milled from a block of 15-lb high density foam and finished to provide a smooth exterior finish and an interior machined to house the waterjets, motors, batteries, and cooling system. Model testing is being conducted in the Davidson Lab towing tank to determine calm water resistance, porpoising stability limits, and performance in waves. The propulsion system, batteries and cooling systems will be arranged to provide optimum performance. The autonomous control and navigation system was installed and tested in a small harbor off the Hudson. The team will travel to Pohick Bay Regional Park in Occoquan, Virginia to participate in the competition on May 26, 2022.
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