Name: Eric Johnson
Alpha: 083414
Major: Mechanical Engineering
Course: EM495
Title: The Effect of Fischer-Tropsch (FT) Synthetic Diesel Fuel in a Production Cummins Medium Duty Engine
Mentor: Prof. Cowart
Abstract: An alternative diesel fuel that can be produced from natural gas and coal (Fischer-Tropsch Process) is being considered by the US Navy as a potential future fuel. This ‘synthetic diesel’ fuel has slightly different properties as compared to conventional diesel fuel (e.g. cetane number, viscosity, etc.). While some studies have compared these two fuels there are still many questions as to how this new fuel will behave in an engine designed to operate only on diesel fuel. This study will use the USNA ’01 Cummins ISB (Dodge Truck) Diesel Engine to evaluate FT Synthetic Diesel Fuel in a standard diesel engine. Steady-state testing will compare base diesel fuel operation and performance at a number of different engine operating conditions. Brake performance and emissions will be the principle metrics for comparison.
Name: Erik Sink
Alpha: 086144
Major: Aeronautical Engineering
Course: EM495
Title: The Effect of Fischer-Tropsch (FT) Synthetic Diesel Fuel in a Cooperative Fuels Research Diesel Engine
Mentor: Professor Jim Cowart
Abstract: An alternative to diesel fuel that can be produced from natural gas and coal (Fisher-Tropsch Process) is being considered by the US Navy as a potential future fuel. This ‘synthetic diesel’ fuel has slightly different properties as compared to conventional diesel fuel (e.g. cetane number, viscosity, etc.). While some studies have compared these two fuels there are still many questions as to how this new fuel will behave in an engine designed to operate only on diesel fuel. This study will use the USNA CFR Diesel Engine to evaluate FT Synthetic Diesel Fuel in a standard diesel engine. Steady-state testing will compare base diesel fuel operation and performance at a number of different engine operating conditions. Indicated performance and emissions will be the principle metrics for comparison at various engine loads, injection timings and compression ratios.Name: John T. Hayashi
Alpha: 082898
Major: EME
Course: EM495
Title: MCNP5 Modeling of the Cesium-137 (Cs137) Response of the DT-702 Thermoluminescent Dosimeter
Mentor: Professor Nelson, Mechanical Engineering Department
Abstract: The objective of this research project is to use Monte Carlo modeling techniques to model the response to gamma photons of the current Navy standard DT-702 thermo luminescent dosimeter (TLD). The DT-702 TLD contains four manganese-copper-phosphorus (MCP) doped LiF chips that are held on a single card surrounded by a plastic card holder. The first task will be to create a functioning model of the DT-702 response using MCNP5 (Monte Carlo N-Particle Transport Code, version 5) modeling software. Once a model has been created, the simulation will be validated through comparisons with experimental data collected at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland.
In order to create a model that will work with the MCNP5 software, other programs must be used. Visual editing programs such as Mortiz and Sabrina will be used to draw the parts. The model consists of a Cs-137 gamma source, the NIST irradiation room and the TLD located on a methyl methacrylate material phantom. The methyl methacrylate is a material whose properties are equivalent to human tissue, which allows for comparisons between the model and real life. The dosimeter card and holder will be modeled as a phantom within the geometry model of the NIST irradiation facility. The output of the model is energy deposition tallies in the four TLD LiF chips. These models will be combined using parallel clusters at the MCNP5 workstation at the Naval Dosimetry Center, located in Bethesda, Maryland. By having a large number of particle histories available by means of the parallel cluster, the results will have statistical significance. An ionization chamber will be modeled within the MCNP5 geometry model and analyzed to provide a second comparison to the empirical NIST data and MCNP5 dose tallies. Much of the project will be based on the work of previous Bowman Scholar, Midshipman 1/C Travis Albright. His report focuses on creating a model that attempted to give an accurate response to gamma and beta radiation. This project will expand on his work by creating a functioning model to be used with the MCNP5 software as well as measuring the effects of radiation on an ionization chamber.
In order to achieve these goals, several errors found in MIDN 1/C Albright’s report must be corrected. While MIDN 1/C Albright was able to build an accurate geometric model of the TLD, he was unable to make his model work with the MCNP5 software. Without a working model, he was unable to verify his model with the empirical data supplied by NIST.
One of the first errors he encountered was that the formulas used to describe the TLD exceeded the word limit for commands in MCNP5. This problem arose because the program created redundancies which were counted twice towards the word limit. In order to combat this problem, the model needs to be simplified and the redundancies eliminated. The analysis will be performed using software available at either the Nucleonics Lab at the Naval Academy or at the Naval Dosimetry Center.
Once a working model has been created, comparisons between the MCNP5 model and the actual data from NIST can be made. The data will be used to verify the model as an accurate representation for the TLD. A follow-up to MIDN 1/C Albright’s report will be to measure the response of an ionization chamber to radiation. The response of the ionization chamber will be measured in the same method as the TLD. Having different sets of data responses will validate the models of the TLD and the ionization chamber. The ionization chamber data can also be used to establish an independent calibration coefficient for the Cs-137 source, which will be accomplished by measuring the charge that accumulates within the ionization chamber.
The overarching objective for the project is to understand the relationship between different forms of incident radiation and the corresponding thermoluminescence of the doped LiF chips. Ultimately, it is hoped that this understanding can be applied to suggest improvements to the dose algorithm for the DT-702 system in complex, mixed dosage situations. This project has value because it will allow the Navy to remain pro-active instead of become reactive in the field of personnel radiation dosimetry. By having a functioning model, analysis can be done on all types of radiation fields without the need to collect time consuming experimental data.
By completing this research project, I hope to get a better understanding of the interactions between nuclear radiation and matter. Being able to understand these atomic reactions will benefit my education as I seek to become a nuclear-trained Naval Officer. In addition, the lessons learned through independent research, as well as the challenges of completing a large research project will help with the foundation of education that I am receiving at the Naval Academy.
Name: Collin Ross Hedges
Alpha: 082964
Major: EME
Course: EM495
Title: The Use of Metal Hydrides for Diver Heating and Cooling
Mentor: Professor Keith W. Lindler
Abstract: Navy divers often conduct operations in difficult environments, which hinder their performance. Water temperature is one aspect of the environment that can limit operations conducted by Navy divers. If the water temperature is too hot (over 90o F) or too cold (less than 45o F), divers fatigue, lose concentration, experience dizziness, and suffer from nitrogen narcosis quicker than in ideal water temperatures. In order to lessen the effects of extreme temperatures, divers wear protective suits that incorporate cooling or heating devices. Electric batteries, or solid state mechanisms can power these heating and cooling devices, but these devices tend to be bulky, expensive, and inefficient. An alternative to these heating methods uses two metal hydrides as a thermal battery to heat or cool the protective suit.
A metal hydride is a metal that can store hydrogen ions in its crystal structure, through either ionic bonding or absorbing the ions in interstitial spaces of the crystal structure. Since the hydrogen is stored within the crystal structure of the metal, a large amount of hydrogen can be stored in a small volume. Various metals can act as metal hydrides, and each metal hydride has different properties, such as heat of absorption and equilibrium pressure. When two dissimilar metal hydrides are connected in a closed system, hydrogen will flow from the high pressure metal hydride to the low pressure metal hydride. This exchange of hydrogen causes an exothermic reaction at the low pressure metal hydride, and an endothermic reaction at the high pressure metal hydride. These thermal reactions can provide either cooling or heating for divers. Since no hydrogen is lost to the environment, the process can be reversed by heating the low pressure metal hydride, and cooling the high pressure metal hydride. Because metal hydrides store large amounts of hydrogen and do not permanently consume hydrogen during the thermal reactions, metal hydrides provide a reusable, compact, and efficient cooling or heating source.
This research project will examine the suitability of the metal hydride HYSTOR 104 for use in a diver heating unit. By pairing HYSTOR 104 with other metal hydrides, and measuring each pair’s hydrogen storage ability, heat transfer rate, and rate of hydrogen flow, cooling and heating effectiveness can be determined. By comparing each tested pair’s effectiveness and the effectiveness of pairs tested in previous studies, the most appropriate metal hydride combination can be chosen to power a diver cooling or heating device. In addition to testing their cooling or heating effectiveness, the feasibility to recharge each pair will be tested. Besides determining the intrinsic heating and cooling capabilities of HYSTOR 104, this research project will also investigate different fin arrangements placed on the metal hydride to aid in heat transfer. By increasing the rate of heat transfer, a more efficient cooling or heating device can be constructed. Developing a metal hydride based cooling or heating unit will provide more adequate thermal protection for Navy divers.
Name: Mark Joseph Horodowicz
Alpha: 083150
Major: EME
Course: EM495
Title: Characterizing Diesel Emissions and Soot via Dilution Tunnels
Mentor: Prof. Caton and Prof. Cowart
Abstract: With the growing demand for oil worldwide and the impending instability of oil markets a need for new fuel and engine technology that conforms to modern specifications is imperative for both the US military and civilian sectors. As research on new fuels, fuel production methods, and engine technology continues, an adaptive and accurate tool for credibly measuring and characterizing the products of fuel combustion tests is necessary. To meet this need, a dilution tunnel will be designed and constructed in support of measuring diesel engine performance under varying operating temperature and running conditions. By being able to characterize engine emissions and soot, an accurate assessment of a diesel engine’s performance during cold start and restart as well as transient and steady state operation is achievable.
Name: Jacob Rozich
Alpha: 085676
Major: Mechanical Engineering
Course: EM495
Title: The Effects of Intake Tuning on Formula SAE Engine Torque and Volumetric Efficiency at Varying Engine Speeds
Mentor: CDR Hamilton
Professor Cowart
Abstract: This research project will investigate the effects of intake tuning on the performance of a Honda CBR600F4I four cylinder, four-stroke internal combustion engine. Research will be conducted in a sequential process of at least two steps. First, data will be collected for straight lengths of intake runners in an attempt to determine the optimum length at a given engine speed over a range of speeds in terms of measurable engine torque and volumetric efficiency. Second, further investigations will be conducted to determine how best to package a given optimum length for a given engine speed within the limited physical constraints of the Formula SAE car. The first goal will be achieved utilizing the 2006 FSAE engine and altered intake manifold prepared during my 2007 summer internship. The engine will be run at different speeds ranging from 3,000 rpm to 14,000 rpm at intervals of 1000 rpm. At each speed, different intake runner lengths will be attached to the intake manifold, and torque, pressure in the manifold, and exhaust air content will be measured at each speed and runner length combination utilizing a dynamometer, a transducer, and an oxygen sensor, respectively. Runner lengths will range from 0.1 meters to 1.5 meters. The primary purpose of documenting this data will be to attempt to determine an ideal intake runner length or lengths for each engine speed.
Once these ideal lengths have been determined, bends, turns, and other alterations will be made to the shapes of intake runners of a given length to determine how such changes will affect engine performance with those runners. Specifically, the study will examine how altering intake runner shape affects the oscillations of the pressure waves within the runners, and consequently the tuning effect achieved in the first portion of the research. This research will be conducted by adding a single bend to a given length of intake runner, recording the effects on air flow and engine torque and volumetric efficiency, and comparing these results with those from the first part of the study. The degree of bend will be increased by increments of 10 degrees, with the same testing being performed after each increase. The ultimate aim of conducting this packaging research is to determine how best to implement intake tuning within the limited confines of the 2008 FSAE car.
If time permits, following completion of intake tuning research, efforts will be made to determine an optimum exhaust length as well. This testing would follow a procedure similar to that outlined above for intake tuning. Lastly, if there is still time available, investigation into an optimum plenum size and shape will be conducted. However, it is unlikely that there will be time, at least this semester, to reach this final stage of research.
Name: Michael Sapienza
Alpha: 085784
Major: Mechanical Engineering
Course: EM495
Title: Material behavior under non-equilibrium, short duration exposure to high temperature
Mentor: CDR Lloyd Brown, USN
Abstract: The current-carrying conductors of a railgun experience immense changes in electro-thermal and magnetic conditions during projectile launch. Temperatures near the conductor melting point and stress near material failure may be achieved during the initial milliseconds of railgun activity. Little is known of these transient conditions on material properties because of the short duration of the launch event. However, such effects on material properties cannot be overlooked in the development of the railgun. The ability to accurately model system behavior is imperative as high tolerances are required in order for the railgun system to function properly.
This research project proposes to combine expanding ring tests with post failure analysis to characterize the stress state and possible failure modes which proposed railgun materials experience during launch. The expanding ring test uses a thin specimen of railgun material surrounding a coil that is in turn expanded via an electrical pulse using a capacitor bank as a power supply. The specimen subsequently expands and fragments due to electromagnetic forces, as a current is induced in the specimen when the expanding coil is pulsed. The event is of such short duration that adiabatic heating occurs in the specimen, allowing for measurement of adiabatic thermal properties while experiencing high strain rates. Expanding ring tests will be a primary source of experimentation due to the ease with which the current, loading rate and electromagnetic forces can be controlled. Some post failure analysis of specimens will be conducted using scanning electron microscopy (SEM) to enable determination of the failure mode and microhardness testing to evaluate the anticipated changes in tensile strength due to annealing.
A larger portion of research will focus on material samples subjected to a Split-Hopkinson Pressure Bar test to reveal behavior at very high rates of strain. While there is no common “Hopkinson” apparatus, the principles remain the same for its construction. A compressed gas launcher will fire a striker bar into an incident bar. The incident bar will send the compressive pulse through the sample. The sample will transfer the excess momentum into a momentum trap via a transmitted bar. Each bar will be of known modulus of elasticity and have strain gages to measure load as a function of time. Loading rate data shows a relationship between deformation of the sample and velocities and forces at the interfaces where the bars and sample are in contact. The data will characterize sample behavior under extreme dynamic strain conditions which may be correlated to events similar to those of the rail gun.
The Hopkinson tests will be correlated with the data from the expanding ring tests to evaluate variation in material properties, namely yield and tensile strength, as a function of strain rate. It is also anticipated that the expanding ring tests will create a higher strain rate than that of the Hopkinson bar, both of which are of a much higher rate than that of a conventional load frame operated at maximum test speed. Between the expanding ring test data and the Hopkinson bar test data, along with tabulated data for material properties from conventional load frame testing, the behavior of prototype railgun materials can be compared over a significant range of strain rates, enabling a more informed decision as to the proper choice for a railgun conducting rail material.
Name: Caitlin Schwamberger
Alpha: 085922
Major: EME
Course: EM495
Title: Influence of Processing on the Mechanical and Environmental Behavior of Nanostructured Cold Spray Coatings
Mentor: Professor Angela Moran
Abstract: The effects of the cold-spraying technique to apply a nano-crystalline coating have not been sufficiently researched to date. This project will continue the research currently being conducted to determine how the composition and application techniques of the coating affect the material and mechanical properties of the sample being coated. The primary material properties being considered are corrosion and fatigue. The mechanical properties will be evaluated using various forms of magnification and analysis.
This project involves analyzing samples of various sprayed techniques to determine the affect of spraying on fatigue and corrosion. Additionally, the samples will be analyzed mechanically to see the structural changes between cold spray, thermal spray, and the various grinds of the powder. These analyses will be used to help determine the optimal composition and application method for jet coatings.
Name: Tucker Stachitas
Alpha: 086360
Major: EME
Course: EM495
Title: Evaluation of Radiological Dispersion Using Hazards Prediction & Assessment Capability Software
Mentor: Professor Martin E. Nelson, Mechanical Engineering
Professor Mark J. Harper, Mechanical Engineering
Abstract: The project begins with using the Hazard Prediction and Assessment Capability (HPAC) software package to analyze radiological dispersion. The program accepts various input conditions to analyze their effect on hazard dispersion. The project will consider variables to include: terrain, humidity, marine environments, and structures. The radiological maps produced will be used as inputs for further research that will evaluate the Aerial Radiological Dispersion and Identification and Mapping System (ARDIMS). Results will also be compared with theoretical radiological dispersion models.
Name: Paul Cronk
Alpha: 081554
Major: Mechanical Engineering
Course: EM495
Title: Characterization of a Combined Spray and Evaporative Cooling Experiment
Mentor: Andrew N. Smith, Associate Professor, Mechanical Engineering
Abstract: The objective of this project will be to conduct a detailed characterization of the blower wind tunnel and the spray nozzles designed to cool a mock rail gun rail. The controls for the different components of the system will be automated in order to be controllable from a computer. The air flow through the barrel will be characterized using hot wire anemometer in order to provide a detailed mapping of the flow velocity and turbulence intensity across the test section. The spray nozzle distribution will be measured along with the exit velocity. The exit velocity will be measured as a function of pressure drop across the nozzle.
Name: 1/C Mark G. Richard
Alpha: 085478
Major: Mechanical Engineering
Course: EM495
Title: Mitigating Propeller Tip Vortex Impingement on a Spade Rudder
Mentor: Professor Flack, Mechanical Engineering Department
Dr. Eric Paterson, Penn State Applied Research Laboratory
Abstract: In high speed marine vessels, corrosion due to propeller and rudder cavitation can cause significant damage to both components, detracting from design life and performance. Sources of cavitation damage to ships’ rudders include surface cavitation, due to propeller induced swirl and rudder angle of attack, and impingement of propeller tip-vortex cavitation. Although surface cavitation can cause damage at high rudder angles, the primary source of corrosion is due to the collapsing of tip-vortex streams on the rudder surface. This experiment involves analysis of the interaction between rudder and tip-vortex stream and will focus on reducing the effects of cavitation by using different hydrofoil shapes to alter the hydrodynamic characteristics of the flow over the rudder. Experiments will be performed in a 12 inch water tunnel, simulating propeller tip vortex impingement on a rudder. Particle Image Velocimetry (PIV) will be used to measure the rudder flow field and to evaluate the influence of propeller tip-vortices on this flow field. PIV will be useful in determining wake features, particularly tip vortex trajectory. Additionally, Computational Fluid Dynamics (CFD) will be used to simulate the same flow conditions as the water tunnel experiment. The use of CFD allows for a number of variables to be easily changed to optimize rudder design. PIV water tunnel experiments will be conducted at the Pennsylvania State University Applied Research Laboratory during a summer internship and CFD computations will be performed at the U.S. Naval Academy using a cluster of parallel processor computers. The goal of the project is to understand the flow field over the rudder, including propeller tip vortices, so that rudder modifications can be designed and developed to reduce tip vortex impingement. Minimizing rudder cavitation will extend service life, reduce corrosion maintenance, and maintain rudder performance, which will cause a decrease in operating cost.Name: Bo Fisher
Alpha: 082178
Major: EGE
Course: EM495
Title: Engineering assessment of forest practice regulations in Pacific Northwest forests
Mentor: Karen Flack
Abstract: The objective of this proposal is to quantify the wind speed and direction, and forest configuration that result in statistically significant damage to mature commercially important tree species logged in the Pacific Northwest that are required to be left standing along riparian buffer zones and other harvest areas by state forest practice regulations. It may be possible to predict and even prevent damage prone areas during the harvest planning stage, and influence revision to the forest practice rules to improve and enhance forest productivity and reduce wind-caused tree wastage.