Mechanical Engineering Commons^™

Research On Development And Application Of Simulated Night Vision Enhancement Systems, Linzhen Nie

Mechanical Engineering Dissertations

Poor visibility due to darkness is believed to be one of the main causes for the high rate of night driving accidents.

Night vision enhancement systems (NVESs) have been developed to improve visibility at night through supplementing drivers' direct vision with additional information shown on a display, rather than replacing drivers' direct vision. Existing studies have shown that NVESs may increase recognition distance, but may also increase drivers' mental and visual distraction (eyes-off-road). Each scan of the display of the night vision enhancement system involves some visual and mental cost to the driver. Automatic pedestrian warnings (APWs) have been integrated ...

Miniature Wire Boom System For Cubsat Application, Keith R. Bradford

All Graduate Plan B and other Reports

No abstract provided.

Thermo-Piezo-Electro-Mechanical Simulation Of Algan (Aluminum Gallium Nitride) / Gan (Gallium Nitride) High Electron Mobility Transistor, Lorin E. Stevens

All Graduate Theses and Dissertations

Due to the current public demand of faster, more powerful, and more reliable electronic devices, research is prolific these days in the area of high electron mobility transistor (HEMT) devices. This is because of their usefulness in RF (radio frequency) and microwave power amplifier applications including microwave vacuum tubes, cellular and personal communications services, and widespread broadband access. Although electrical transistor research has been ongoing since its inception in 1947, the transistor itself continues to evolve and improve much in part because of the many driven researchers and scientists throughout the world who are pushing the limits of what modern ...

Design And Fabrication Of An Ultra-Low Capacitive Pressure Transducer, Justin Brown, Armand Gagne, Stephen Charnley, Kyle Devlin, Ryan Finley, Jenan Almishari, Anna Wint, Dr. Shahin Nudehi

Celebration of Undergraduate Scholarship

The goal of the Capacitive Pressure Sensor project is to redesign the Alpha Instruments 168 series capacitive pressure sensor sold by Dwyer Instruments. The primary objectives of the new design will be to eliminate the use of welding in the assembly of the sensor components and to eliminate stray capacitance in the system measurements through the use of dielectric boundaries. Additionally, the sensor housing will be a stamped design in order to avoid expensive machining steps. The electrical components of the system will be tailored to accept a capacitive signal and transfer it to a voltage reading. This voltage will ...

Development Of An Optimization Model For Biofuel Facility Size And Location And A Simulation Model For Design Of A Biofuel Supply Chain, Fengli Zhang

Theses and Dissertations

To mitigate greenhouse gas (GHG) emissions and reduce U.S. dependence on imported oil, the United States (U.S.) is pursuing several options to create biofuels from renewable woody biomass (hereafter referred to as “biomass”). Because of the distributed nature of biomass feedstock, the cost and complexity of biomass recovery operations has significant challenges that hinder increased biomass utilization for energy production. To facilitate the exploration of a wide variety of conditions that promise profitable biomass utilization and tapping unused forest residues, it is proposed to develop biofuel supply chain models based on optimization and simulation approaches. The biofuel supply ...

Impact Of E22 On Two-Stroke And Four-Stroke Snowmobiles, James Corey Weber

Theses and Dissertations

A push to reduce dependency on foreign energy and increase the use of renewable energy has many gas stations pumping ethanol blended fuels. Recreational engines typically have less complex fuel management systems than that of the automotive sector. This prevents the engine from being able to adapt to different ethanol concentrations. Using ethanol blended fuels in recreational engines raises several consumer concerns. Engine performance and emissions are both affected by ethanol blended fuels.

This research focused on assessing the impact of E22 on two-stroke and four-stroke snowmobiles. Three snowmobiles were used for this study. A 2009 Arctic Cat Z1 Turbo ...

Laser Thomson Scattering Measurements Of Electron Temperature And Density In A Hall-Effect Plasma, Robert L. Washeleski

Theses and Dissertations

Hall-effect thrusters (HETs) are compact electric propulsion devices with high specific impulse used for a variety of space propulsion applications. HET technology is well developed but the electron properties in the discharge are not completely understood, mainly due to the difficulty involved in performing accurate measurements in the discharge. Measurements of electron temperature and density have been performed using electrostatic probes, but presence of the probes can significantly disrupt thruster operation, and thus alter the electron temperature and density. While fast-probe studies have expanded understanding of HET discharges, a non-invasive method of measuring the electron temperature and density in the ...

Torque Converter Turbine Noise And Cavitation Noise Over Varying Speed Ratio, Chad Michael Walber

Theses and Dissertations

These investigations will discuss the operational noise caused by automotive torque converters during speed ratio operation. Two specific cases of torque converter noise will be studied; cavitation, and a monotonic turbine induced noise. Cavitation occurs at or near stall, or zero turbine speed. The bubbles produced due to the extreme torques at low speed ratio operation, upon collapse, may cause a broadband noise that is unwanted by those who are occupying the vehicle as other portions of the vehicle drive train improve acoustically. Turbine induced noise, which occurs at high engine torque at around 0.5 speed ratio, is a ...

Computational Fluids Domain Reduction To A Simplified Fluid Network, Robert E. Smith

Theses and Dissertations

The primary goal of this project is to demonstrate the practical use of data mining algorithms to cluster a solved steady-state computational fluids simulation (CFD) flow domain into a simplified lumped-parameter network. A commercial-quality code, “cfdMine” was created using a volume-weighted k-means clustering that that can accomplish the clustering of a 20 million cell CFD domain on a single CPU in several hours or less. Additionally agglomeration and k-means Mahalanobis were added as optional post-processing steps to further enhance the separation of the clusters. The resultant nodal network is considered a reduced-order model and can be solved transiently at a ...

Study Of The Effect Of Biodiesel Fuel On Passive Oxidation In A Catalyzed Particulate Filter, Kenneth L. Shiel

Theses and Dissertations

A 2007 Cummins ISL 8.9L direct-injection common rail diesel engine rated at 272 kW (365 hp) and 317 kW (425 hp) was used to load the filter to 2.2 g/L and passively oxidize particulate matter (PM) within an aftertreatment system consisting of a diesel oxidation catalyst (DOC) and catalyzed particulate filter (CPF). The tests conducted with the engine rated at 365 hp used a 2007 DOC and CPF. The tests conducted with the engine rated at 425 hp used a 2010 DOC and 2007 CPF. Understanding the passive NO₂ oxidation kinetics of PM within the CPF ...

Use Of Manual Adaptive Remeshing In The Mechanical Modeling Of An Intraneural Ganglion Cyst, Laura M. Roberts

Theses and Dissertations

Intraneural Ganglion Cysts expand within in a nerve, causing neurological deficits in afflicted patients. Modeling the propagation of these cysts, originating in the articular branch and then expanding radially outward, will help prove articular theory, and ultimately allow for more purposeful treatment of this condition. In Finite Element Analysis, traditional Lagrangian meshing methods fail to model the excessive deformation that occurs in the propagation of these cysts. This report explores the method of manual adaptive remeshing as a method to allow for the use of Lagrangian meshing, while circumventing the severe mesh distortions typical of using a Lagrangian mesh with ...

Automated Optimization Of Polymer Extrusion Dies Using Finite Element Analysis, James Allen Peitzmeier

Theses and Dissertations

An extrusion die is used to continuously produce parts with a constant cross section; such as sheets, pipes, tire components and more complex shapes such as window seals. The die is fed by a screw extruder when polymers are used. The extruder melts, mixes and pressures the material by the rotation of either a single or double screw. The polymer can then be continuously forced through the die producing a long part in the shape of the die outlet. The extruded section is then cut to the desired length. Generally, the primary target of a well designed die is to ...

Regional Comparisons Of Nano-Mechanical Properties Of The Human Meniscus; Structure And Function, John Thomas Moyer

Theses and Dissertations

Osteoarthritis (OA) is a debilitating disease that is becoming more prevalent in today’s society. OA affects approximately 28 million adults in the United States alone and when present in the knee joint, usually leads to a total knee replacement. Numerous studies have been conducted to determine possible methods to halt the initiation of OA, but the structural integrity of the menisci has been shown have a direct effect on the progression of OA. Menisci are two C-shaped structures that are attached to the tibial plateau and aid in facilitating proper load transmission within the knee. The meniscal cross-section is ...

Development Of One-Dimensional And Two-Dimensional Computational Tools That Simulate Steady Internal Condensing Flows In Terrestrial And Zero-Gravity Environments, Soumya Asimkumar Mitra

Theses and Dissertations

This dissertation presents an effective quasi one-dimensional (1-D) computational simulation tool and a full two-dimensional (2-D) computational simulation methodology for steady annular/stratified internal condensing flows of pure vapor. These simulation tools are used to investigate internal condensing flows in both gravity as well as shear driven environments. Through accurate numerical simulations of the full two dimensional governing equations, results for laminar/laminar condensing flows inside mm-scale ducts are presented. The methodology has been developed using MATLAB/COMSOL platform and is currently capable of simulating film-wise condensation for steady (and unsteady flows). Moreover, a novel 1-D solution technique, capable of ...

Structural Response And Dynamics Of Fluid-Structure-Control Interaction In Wind Turbine Blades, Lucan Ignacio Lago

Theses and Dissertations

Reducing the uncertainties related to blade dynamics by the improvement of the quality of numerical simulations of the fluid structure interaction process is a key for a breakthrough in wind-turbine technology. A fundamental step in that direction is the implementation of aeroelastic models capable of capturing the complex features of innovative prototype blades, so they can be tested at realistic full-scale conditions with a reasonable computational cost.

We make use of a code based on a combination of two advanced numerical models implemented in a parallel HPC supercomputer platform: First, a model of the structural response of heterogeneous composite blades ...

Treatment Of Osteoporosis In A Mouse Model Of Duchenne Muscular Dystrophy Using Black Bear Parathyroid Hormone, Sarah K. Gray

Theses and Dissertations

Duchenne muscular dystrophy (DMD) is a progressive disease affecting skeletal and cardiac muscle, as well as bone. Long term disuse and glucocorticoid treatments cause progressive osteoporosis in DMD patients, leading to an increase in fracture incidence. Treatments for osteoporosis in these patients have not been widely explored. Parathyroid hormone (PTH), an anabolic treatment for post-menopausal osteoporosis, could benefit DMD patients by improving skeletal properties and reducing fracture risk. Other PTH analogues are not currently FDA approved to treat osteoporosis, but may have improved osteogenic effects compared to the human analogue. Black bear PTH is especially promising as an osteoporosis treatment ...

Algorithms For Spacecraft Formation Flying Navigation Based On Wireless Positioning System Measurements, Shu Ting Goh

Theses and Dissertations

Spacecraft formation flying navigation continues to receive a great deal of interest. The research presented in this dissertation focuses on developing methods for estimating spacecraft absolute and relative positions, assuming measurements of only relative positions using wireless sensors. The implementation of the extended Kalman filter to the spacecraft formation navigation problem results in high estimation errors and instabilities in state estimation at times. This is due tp the high nonlinearities in the system dynamic model. Several approaches are attempted in this dissertation aiming at increasing the estimation stability and improving the estimation accuracy.

A differential geometric filter is implemented for ...

Space Trajectories Optimization Using Variable-Chromosome-Length Genetic Algorithms, Ahmed Hamdy Gad Elsayed Gad

Theses and Dissertations

The problem of optimal design of a multi-gravity-assist space trajectories, with free number of deep space maneuvers (MGADSM) poses multi-modal cost functions. In the general form of the problem, the number of design variables is solution dependent. To handle global optimization problems where the number of design variables varies from one solution to another, two novel genetic-based techniques are introduced: hidden genes genetic algorithm (HGGA) and dynamic-size multiple population genetic algorithm (DSMPGA).

In HGGA, a fixed length for the design variables is assigned for all solutions. Independent variables of each solution are divided into effective and ineffective (hidden) genes. Hidden ...

Study On The Feasibility Of Universal Chip Control In Machining, Thimmaiah Kumera Ganapathi

Theses and Dissertations

A novel solution to the long standing issue of chip entanglement and breakage in metal cutting is presented in this dissertation. Through this work, an attempt is made to achieve universal chip control in machining by using chip guidance and subsequent brea-kage by backward bending (tensile loading of the chip’s rough top surface) to effectively control long continuous chips into small segments. One big limitation of using chip breaker geometries in disposable carbide inserts is that the application range is limited to a narrow band depending on cutting conditions. Even within a recommended operating range, chip breakers do not ...

Implementation Of A Phenomenological Evaporation Model Into A Porous Network Simulation For Water Management In Low Temperature Fuel Cells, David L. Fritz Iii.

Theses and Dissertations

A phenomenological transition film evaporation model was introduced to a pore network model with the consideration of pore radius, contact angle, non-isothermal interface temperature, microscale fluid flows and heat and mass transfers. This was achieved by modeling the transition film region of the menisci in each pore throughout the porous transport layer of a half-cell polymer electrolyte membrane (PEM) fuel cell. The model presented in this research is compared with the standard diffusive fuel cell modeling approach to evaporation and shown to surpass the conventional modeling approach in terms of predicting the evaporation rates in porous media.

The current diffusive ...