Mechanical Engineering Commons^™

Triggering The Solar Revolution, Justin Halversen, John Salmon

Journal of Undergraduate Research

The sun’s energy emissions are significantly higher than other alternative energy sources. All other energy sources combined would not provide even one percent of the potential collectible energy from the sun. The amount of potential solar power available is well over 5000 times the current world consumption. Indeed, there is a very large and renewable reservoir of untapped potential solar energy which could be made more directly available to more people.

An Experimental Study On Drag Reduction Of Aftermarket Additions On An Suv, Christiana L. Katsoulos

Senior Honors Projects, 2010-2019

Over recent years, the awareness of climate change has become more prevalent worldwide and one major contributor to global warming has been the use of transportation. Vehicles contribute to global warming by releasing petroleum based emissions such as significant amounts of carbon dioxide and numerous other harmful environmental pollutants. SUVs contribute to the emissions problem more so than sedans, since they have lower gas mileage and need more gasoline regularly. The main functionality of sport utility vehicles, or SUVs, includes hauling or off-roading and fuel efficiency is not always the focus in the design process. However, aerodynamic enhancements could improve …

Investigating The Classical And Non-Classical Mechanical Properties Of Gan Nanowires, Mohammad Reza Zamani Kouhpanji

Electrical and Computer Engineering ETDs

Study and prediction of classical and non-classical mechanical properties of GaN is crucial due to the potential application of GaN nanowires (NWs) in piezoelectric, probe-based nanometrology, and nanolithography areas. GaN is mainly grown on sapphire substrates whose lattice constant and thermal expansion coefficient are significantly different from GaN. These discrepancies cause mechanical defects and high residual stresses and strains in GaN, which reduce its quantum efficiency.

Specifically, for nanoscale applications, the mechanical properties of materials differ significantly compared to the bulk properties due to size-effects. Therefore, it is essential to investigate the mechanical properties of GaN NWs using the non-classical …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

No abstract provided.

College Of Engineering Senior Design Competition Spring 2017, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Engineering Honor Society Induction Ceremonies

Design & Analysis Of Cycloconverter To Run Split Phase Induction Motor Using Pwm Control, Iftakher Ahmed

Student Theses and Dissertations

Frequency drive is playing an important role for ever growing demand of industrial applications. Cycloconverter is one such device which generates variable frequency depending on the load. Semiconductor switching devices like Thyristor, Insulated Gate Bipolar Transistor (IGBT) make it possible to control the output frequency according to the requirement. Because of energy efficient characteristics, single phase induction motors are widely accepted in industrial sectors. To control the speed and electromagnetic torque of a motor for the particular frequency a Cycloconverter is used to increase the system frequency with a technique known as pulse width modulation (PWM) control. To drive varying …

A Constraint Programming Approach For The Team Orienteering Problem With Time Windows, Ridvan Gedik, Emre Kirac, Ashlea Bennet Milburn, Chase Rainwater

Mechanical and Industrial Engineering Faculty Publications

The team orienteering problem with time windows (TOPTW) is a NP-hard combinatorial optimization problem. It has many real-world applications, for example, routing technicians and disaster relief routing. In the TOPTW, a set of locations is given. For each, the profit, service time and time window are known. A fleet of homogenous vehicles are available for visiting locations and collecting their associated profits. Each vehicle is constrained by a maximum tour duration. The problem is to plan a set of vehicle routes that begin and end at a depot, visit each location no more than once by incorporating time window constraints. …

Assessing The Importance Of The Root Mean Square (Rms) Value Of Different Waveforms To Determine The Strength Of A Dielectrophoresis Trapping Force, Jordan Gilmore, Monsur Islam, Josie Duncan, Rucha Nato, Rodrigo Martinez-Duarte

Publications

No abstract provided.

Assessing The Importance Of The Root Mean Square (Rms) Value Of Different Waveforms To Determine The Strength Of A Dielectrophoresis Trapping Force, Jordon Gilmore, Monsur Islam, Josie Duncan, Rucha Natu, Rodrigo Martinez-Duarte

Publications

No abstract provided.

Automation In Entertainment: Concept, Design, And Application, Ryan Thally

Undergraduate Honors Theses

The focus of this thesis is to explore the automation technology used in the modern entertainment industry. Upon completion of my thesis, I will deliver a working prototype of the chosen technology and present its capabilities in a choreographed show.

Wettability Tailoring Of Nanotube Carpets: Morphology-Chemistry Synergy For Hydrophobic–Hydrophilic Cycling, Lymeng He, Anil Karumuri, Sharmila M. Mukhopadhyay

Mechanical and Materials Engineering Faculty Publications

Carpet-like arrays of carbon nanotubes (CNTs) on graphitic carbon materials have been investigated in order to understand all-carbon hierarchical structures for multifunctional surface-active devices. Pure CNT carpets are seen to be super-hydrophobic as long as they are well aligned. For future applications involving aqueous environments, the ability to tailor the surface wettability and switch it on demand can be very useful, and enable unprecedented devices related to microfluidics, catalysis and sensing/detection systems. In this study, microwave plasma treatments were used to functionalize CNT carpets for a progressive increase in wettability so that they could eventually become super-hydrophilic. This change could …

Computer Simulation Of Pore Migration Due To Temperature Gradients In Nuclear Oxide Fuel, Ian Wayne Vance

Graduate Theses and Dissertations

A phase-field simulation model is being presented that captures the thermal-gradient-driven migration of pores in oxide fuel associated with fuel restructuring. The model utilizes a Cahn-Hilliard equation supplemented with an advection term to describe the vapor transport of fuel material through the pore interior due to gradients in vapor pressure. In addition, the model also captures changes in a migrating pores’ morphology. Simulations demonstrate that the model successfully predicts pore migration towards the hottest portion of the fuel, the centerline. The simulations also demonstrate changes in pore shape that are in agreement with previous experimental observations. Initially isotropic pores are …

Characterization Of Plastic Deformation Evolution In Single Crystal And Nanocrystalline Cu During Shock By Atomistic Simulations, Mehrdad Mirzaei Sichani

Graduate Theses and Dissertations

The objective of this dissertation is to characterize the evolution of plastic deformation mechanisms in single crystal and nanocrystalline Cu models during shock by atomistic simulations. Molecular dynamics (MD) simulations are performed for a range of particle velocities from 0.5 to 1.7 km/s and initial temperatures of 5, 300 and 600 K for single crystal models as well as particle velocities from 1.5 to 3.4 km/s for nanocrystalline models with grain diameters of 6, 11, 16 and 26 nm. For single crystal models, four different shock directions are selected, <100>, <110>, <111> and <321>, and dislocation density behind the shock wave …

Feasibility Of Using Oxide Thickness Measurements For Predicting Crack Growth Rates In P91 Steel Components, Ralph Edward Huneycutt Iv

Graduate Theses and Dissertations

There are only few methods available for predicting the age of cracks that are found in high

temperature structural components during service; among the promising ones is the oxide

thickness measurement technique. Oxide thickness profiles are taken from crack surfaces of

components and used for predicting the rates of crack propagation. This technique is particularly

suitable for high temperature components fabricated from ferritic steels commonly used in power

plants that run on fossil fuels. To implement this technique, it is necessary to fully understand the

kinetics of high temperature oxidation in these steels. In this study, the oxidation characteristics

of …

The Intersection Of Manufacturing Technologies And School Music Programs, Leslie Prunier

University Scholar Projects

The objective of this project is to design and manufacture a musical instrument, a marching baritone horn, out of plastic. It is constructed out of both PVC pipe and 3D-printed components. Utilizing this project’s documentation, a high school student could use a 3D printer and other basic tools to make their own musical instrument for a fraction of the cost of purchasing one. This documentation will produce a horn tuned in the key of B flat with one functioning valve, and suggestions for future work to make the other two valves functional as well.

Gain Scheduling Controller For Aircraft With Mass And Inertia Variation, Eunyoung Kim

Mechanical and Aerospace Engineering Dissertations - Archive

Robustness is one of the main control design requirements for aircraft control.Robustness is sought in the stability and performance of closed loop system against various factors such as disturbance, measurement error, modeling error or un-modeled dynamics. In aircraft control design, it is common to assume that the mass and inertia properties of aircraft are constant. Further, aircraft is assumed to have symmetry inits mass distribution relative to its mid-vertical plane. There are, however, cases where the aircraft mass changes rapidly, most notably in aerial refueling operation.The mass change also results in changes in the inertia matrix. An aircraft may also …

On Space Program Planning: Quantifying The Effects Of Spacefaring Goals And Strategies On The Solution Space Of Feasible Programs, Mark Douglas Coley

Mechanical and Aerospace Engineering Dissertations - Archive

An organization's space program represents the coalescence of top-level goals and strategies with the specific, lower-level combinations of mission architectures, hardware, and technology. High costs and long lead times necessitate substantial planning and key decisions to be made years, possibly decades, in advance. Unfortunately, the methods and processes available for planning have historically been unable to provide decision-makers with objective, quantitative information from both the top and lower levels of the space program. Instead, decision-makers are forced to turn to top-level, qualitative assessments, disconnected from any of the fundamental, technical details, where inconsistent comparisons and secondary effects often become the …

Studying Effects Of Adhesive Layer On Electrical Signals Of Piezoelectric Transducer Bonded With Structure, Md Mazharul Islam

Mechanical and Aerospace Engineering Dissertations - Archive

Piezoelectric wafer active sensors (PWAS) are the most attractive transducers for guided-wave or ultrasound based structural health monitoring (SHM) because of their light weight and compact size. In order to excite guided waves in a structure, the PWASs are usually bonded on the surface of the structure by adhesive materials. The electrical signal applied to the surface bonded PWAS is converted to mechanical deformation of the PWAS which in turn is transferred to the structure through the adhesive layer. Thus, understanding the effects of the adhesive layer on the electrical response of the PWAS enables us to optimize the mechanical …

Nonlinear Model Predictive Control For Cooperative Control And Estimation, Pengkai Ru

Mechanical and Aerospace Engineering Dissertations - Archive

Recent advances in computational power have made it possible to do expensive online computations for control systems. It is becoming more realistic to perform computationally intensive optimization schemes online on systems that are not intrinsically stable and/or have very small time constants. Being one of the most important optimization based control approaches, model predictive control (MPC) has attracted a lot of interest from the research community due to its natural ability to incorporate constraints into its control formulation. Linear MPC has been well researched and its stability can be guaranteed in the majority of its application scenarios. However, one issue …

Characterization Of Vertically Split Distribution-Wet Cooling Media Used In Data Centers, Mullaivendhan Varadharasan

Mechanical and Aerospace Engineering Theses - Archive

Data Centers houses substantial number of information technology (IT) equipment like computer servers and storage modules associated with various electronic components which consume high volume of electricity. The IT equipment in data center housing keeps dissipates heat energy as it is constantly running day and night. To keep the data center environment under thermally control and to favor the reliability of electronic components, we need to adopt a cooling technique which aids the module level cooling, with due consideration of the size of the data center and its geographical location. One of the adopted cooling technique in data center thermal …

Composite Plate Optimization With Structural And Manufacturing Constraints, Deepak Polaki

Mechanical and Aerospace Engineering Theses - Archive

This is a design optimization study that focuses on the value of free size optimization technology on composite structures which incorporates realistic structural requirements and practical manufacturing limitations to achieve an iterative design with effective structural performance. To detail a study on such practical implementation, a sample structure is required. A rectangular composite laminate with a central hole cutout is considered for this study and is designed using finite elemental tools which includes compression, tension and shear loading conditions with load reactions at bolted joints and buckling stability. Free size optimization and size optimization are used in this study to …

Reliability Assessment Of Solder Joint Using Bga Package – Megtron 6 Versus Fr4 Printed Circuit Boards, Mugdha Anish Chaudhari

Mechanical and Aerospace Engineering Theses - Archive

When it comes to the mechanical and electrical seam of the Printed Circuit Board (PCB) and package, reliability of the board plays a major impact on PCB. As the frequency increases, losses in signals increase. This necessitates the use of new materials for such applications. Nelco 4000-13EPSI, Rogers 4350B, Panasonic Megtron 6 are few high-speed materials used. Studies have shown that Megtron 6 has the least dielectric losses so far, low transmission loss, high heat resistance and has low weight loss than the FR-4 boards. With an increasing demand for high performance, reliability and lower costs, the field of electronic …

Solder Joints Design Optimization Of Qfn Packages For Different Boards By Investigating Solder Joint Reliability, Rishikesh Vilas Tendulkar

Mechanical and Aerospace Engineering Theses - Archive

Quad Flat No-lead package (QFN) is one of the most cutting-edge technologies emerged in the market, exhibiting high performance and efficiency with unparalleled cost effectiveness. QFN, a leadless package, is an ideal choice for applications where size, weight thermal and electrical characteristics are critical, particularly in mobile and handheld devices. Applications like automotive, defense and high current circuits require the package to be mounted on thick printed circuit boards (PCB). The motivation of this work is to understand the effect of design variations of solder joints affecting reliability and optimize the solder package to improve reliability for application on different …

An Improved Method For Measurement Of Radial Thermal Conductivity Of Cylindrical Bodies, Salwa Shaik

Mechanical and Aerospace Engineering Theses - Archive

Li-ion cells are ubiquitously found in day to day electronic devices due to their high power density storage capacity. These batteries are known to exhibit sharp reduction in performance at high temperature. Due to this, several attempts have been made in the past to measure thermal properties of the Li-ion cell. This work improves upon past measurements by showing that heat loss during measurements is non-negligible, and by developing an analytical model to account for such heat loss. Experimental measurements carried out on multiple materials demonstrate non-negligible heat loss. When accounted analytically, these data result in thermal conductivity values that …

Electro-Pneumatic Shifting And Servo Control Of A Clutch For A Fsae Racecar, Rahul Janardhan Chalmela

Mechanical and Aerospace Engineering Theses - Archive

FSAE is an international student design competition held by SAE International where students design, build and compete in static events like cost, design and dynamic events ranging from acceleration, autocross to endurance. UTA Racing has been a part of FSAE since 1982 and have been using a mechanical design for their shifter and clutch since then. This year for the 2017 design competition an electro-pneumatic system is developed to replace the mechanical system. This system consists of pneumatic cylinders controlling a sequential shifter and a servo clutch. The cylinders are controlled using direction control valves, these receive their signals from …

Rack Level Study Of Hybrid Cooled Servers Using Warm Water Cooling With Variable Pumping For Centralized Coolant System, Chinmay Sanjay Kshirsagar

Mechanical and Aerospace Engineering Theses - Archive

As the worldwide demand for the data centers grows, so does the size and load placed on data centers which leads to the applied constraints on power and space available to the operator. Cooling power consumption is a major contributor of the total energy consumption of the system. In the process of optimization of cooling energy consumption per performance unit, liquid cooling technology has emerged as one of the most viable solutions. In this rack level study, 2OU (Open U) hybrid cooled web servers are tested for an evaluation of warm water cooling in centralized coolant system. Effects of higher …

Load Carrying Capacity Management Of Compound Anisotropic Composite Rings Under External Pressure, Salman Bakhrayba

Mechanical and Aerospace Engineering Theses - Archive

Composites have much higher strength than conventional materials such as steel. This makes it attractive to replace heavy loaded structural elements, made traditionally from steel, by elements made from composites. However, it is not a trivial task for statically indeterminate structures due to anisotropy of elastic and strength properties of composites. Present investigation is done for a ring subjected to external load. Such rings are used as bulkheads in many applications. Dependence of ultimate external pressure on thickness of the ring is nonlinear one. It is related to non-uniformity of distribution of circumferential stresses, with anisotropy of material, with set …

Comparative Study Of Viscoelastic Modeling And Linear Modeling For Wafer Level Chip Scale Package Under Drop Impact, Navya Sri Reddy Kasi Reddy

Mechanical and Aerospace Engineering Theses - Archive

Wafer level chip scale packages are one the preferred choice in the electronic industry to meet the need of new miniaturization of the recent devices. It has high efficiency in packaging and has low cost. On the other hand, the drop impact failure is one of the growing risk in day to day use of the portable devices. Therefore, to ensure product quality and to integrate more complicated functionality in these devices comprehensive reliability tests need to be performed before delivering the product. Accelerated thermal cycling, drop testing and power cycling are some accepted test methods used to access board …

A Comparative Study Of Wooden And Composite Crossarm Of An Electric Utility Pole, Amith Venkatesh

Mechanical and Aerospace Engineering Theses - Archive

Currently, most of the crossarms existing in the nation are made of wood. However, wood has a set of negative features like shorter life span due to environmental cracking, damages by insects and birds. Secondly, an insufficient strength and stiffness which is compensated either by increasing the cross-section or by reducing the span between two poles. Also, it’s reduced insulating property in case of high humidity of air which can be accounted to its hygroscopic behavior. Replacement of wooden crossarms by composite crossarms is a known solution to many problems. However, the existing projects are far from optimal. Present investigation …