Mechanical Engineering Commons^™

Analysis And Comparison Between A Conventional Metal And A Metal-Composite Marine Propeller Shaft, Kaushal Mayankkumar Shah

Mechanical and Aerospace Engineering Theses - Archive

The basic principal of a ship propulsion is the reactive (thrust) force generated by the propellers against the stream of water which forces the ship to propel in the opposite direction. The Shafting system is thus required to transmit the necessary torque to the propeller at a certain speed. Studies have suggested that shafts are the most common reason of failures among the whole marine propulsion system comprising of the main engine and propeller apart from the shaft. Stress concentration and torsional vibrations are the two major causes of failure in the propulsion shafting systems based on the case study …

Comparison Of Steel And Composite Leaf Springs Using Fea, Prashik Sunil Gaikwad

Mechanical and Aerospace Engineering Theses - Archive

Composite materials are widely used in aeronautical, marine and automotive industries, because of their excellent mechanical properties, low density and ease of manufacture. Due to this increasing trend to utilize composite materials, it has become necessary to investigate the pros and cons of composites. Increasing competition and innovation in automobile sector tends to modify the existing products by new and advanced material products. A suspension system of vehicle is also an area where these innovations are carried out regularly. Leaf springs are one of the oldest suspension components that are being still used widely in automobiles. They contribute to 15-20% …

Experimental Analysis Of The Effects Of Single-Phase Immersion Cooling Of Optical Interconnects On Mechanical Properties Of Active Optical Cables, Hrishabh Singh

Mechanical and Aerospace Engineering Theses - Archive

Active optical cables (AOC) are being increasingly adopted for data communication and storage, networking, and high-performance computing (HPC) applications. However, their ability to meet higher data-rate requirements necessitates increased heat dissipation demands in fiberoptic datacom systems. Many dielectric coolants having heat capacities much higher than that of air are available in the market. However, there is a lack of literature and data on the reliability of using single-phase dielectric fluids for immersion-cooling of inter and intra-rack optical interconnections in data centers. Industry standards and prevalent aging test methods for optical cables prove insufficient as they do not address immersion in …

Accelerated Creative Problem Solving And Product Improvement Applied To Experimental Devices In A Bloodstain Pattern Interpretation Class--Improving The Role Of Insight Development Tools As A Generator Of New Ideas In Novel Situations, Douglas Ridolfi

Creativity and Change Leadership Graduate Student Master's Projects

This project uses an action research centered study protocol to examine the effects of a problem-based learning exercise related to bloodstain pattern interpretation in a crime scene processing and general criminalistics class taught as part of an upper division forensic chemistry major in a four year college. The goal is to apply design principles and creative problem solving methods directly adapted to a project involving interpreting a set of crime scene photographs depicting blood spatter and with the aid of guided exercises in ideation and design, lead students into the development of alternate theories of how the bloodstains were created …

Design And Optimization Of Mixed Ionic-Electronic Conductive Material For Use In Solid Oxide Fuel Cell Utilizing Carbon Nanotubes, Shiuan Duo Chiang

Mechanical and Aerospace Engineering Theses - Archive

Triple phase boundary (TPB) is considered to be an important limiting factor of the fuel cell performance. Triple phase boundary is a geometrical line where the ionic, electronic and gaseous fuel phase of the fuel cell comes in contact. Electrochemical reactions of the fuel cell occur at the TPB sites. The TPB length greatly impacts the efficiency of the fuel cells. Carbon nanotubes have recently been shown to enhance oxygen reduction reaction (ORR) of the fuel cell and transfer electrons with its conductive properties. CNT also provides porosity in the electrode and could facilitate mass transport. CNT allows for oxygen …

Finite Element Analysis And Design Improvement Of Aerospace Composite Hinges, Gaurang Girish Sonpal

Mechanical and Aerospace Engineering Theses - Archive

Hinges are the most commonly used mechanical bearings to connect 2 objects for relative rotational motion. Modern day aerospace hinges are generally made using either Aluminum, Steel or bronze. The study analyzes the use of composite material as an alternative to traditional materials for manufacturing these hinges. The research is focused on the Finite element Analysis of a composite hinge as well as an aluminum hinge. The load capacity of both the types of hinges are compared. To improve the design of the composite hinge, a combination of composite material and aluminum is used to model a hybrid hinge design. …

General Methods For The Thermal Design Of Data Centers Based On Evaporative Cooling, Raghvendra Parinam

Mechanical and Aerospace Engineering Theses - Archive

With the increasing load on the servers, the cost and energy required to cool a data center has been on the rise. This has kept the researchers to explore more efficient and economical cooling technologies for data centers. One such technology is evaporative cooling. The evaporative cooling systems are one of the most effective methods available for cooling the data centers. So, developing the generic methods for the thermal design of data centers is of utmost importance. This research aims to identify, develop and validate the thermal model for Direct Evaporative Cooling and Indirect Evaporative Cooling. By taking the environmental …

Psychrometric Bin Analysis For Data Center Cooling Modes Using Artificial Neural Networks, Abhishek Uday Walekar

Mechanical and Aerospace Engineering Theses - Archive

With an increase in the need for energy efficient data centers, a lot of research is being done to increase the use of Air Side Economizers (ASEs), Direct Evaporative Cooling (DEC), Indirect Evaporative Cooling (IEC) and multistage I/DEC cooling. The cooling strategies used to control these systems is based on typical meteorological year (TMY) weather data and thermodynamic principles. But the main drawback of these control strategies is that they do not account for the nonlinearities developed by the conditions inside the data center. So, the primary objective of this study is to use Artificial Neural Networks (ANN) for predicting …

Comparison Of Cross-Sectional Profiles For Side Impact Crash Structure In Passenger Vehicle, Nitish Sharma

Mechanical and Aerospace Engineering Theses - Archive

Car’s safety is most important structural criteria while designing an automotive chassis. To protect the occupants from a direct impact, the passenger cabin and the structure of the vehicle should have an appropriate stiffness so that the it absorbs any kind of impact and keeps the passenger safe. Design standards are set by various vehicle safety association around the world based on different crash situations i.e. front crash, side impact, roll over etc. Among these standards, side impact crash account for over all 40% crashes all around the world and is one of the most fatal crash scenarios. This research …

On The Development Of A Human Thumb Tracking Device For Telemanipulation, Abdul Hafiz Abdul Rahaman

Mechanical and Aerospace Engineering Theses - Archive

The human thumb is the first digit of the hand and influences the grasping capability of the human hand. Based on literature, most sensor gloves available capture the motion of the fingers, however, they lack the ability to capture the motion of the thumb. This research focuses on developing a methodology and associated hardware to capture the complex joint motion of the thumb and map it to an in-house developed multi-degree of freedom robotic thumb. A sensor device was developed to measure four joint angles of the human thumb, namely three flexion/extension (flex/ext) joint angles of carpometacarpal (CMC), metacarpophalangeal (MCP), …

Aquaponic System Design And Modeling Ammonia Production: An Overview Of Aquaponics, Spencer Davis Wright

Graduate Theses - Mechanical Engineering

The study of aquaponics in academia has been slowly gaining momentum, but the majority of the research and testing performed is done in an informal, backyard setting. This publication seeks to collate the widespread information into a singular location, as well as to outline various methods by which the necessary tasks can be accomplished. The ammonia production rate of the aquatic life in the system, whether living or deceased, was also explored in order that a more accurate model of the ammonia and nitrate levels of the system may be created. It was found that 20 tilapia produced approximately 3,300 …

Numerical Evaluation Of Energy Release Rate At Material Interfaces For Fatigue Life Predictions, Robert L. Hendrickson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Composite materials are becoming popular in almost all industries. Carbon-fiber and glass-fiber composites are used in aircraft, sports equipment, boats, prosthetics, and wind turbine blades. In all these applications, the composites are subjected to different loads. Loads can take the form of impact or cyclic/fatigue loading, both of which decrease the strength of composites as micro-cracks grow through the composite. Composite laminates are made up of fiber plies (thin layers of fiber) and the fibers are surrounded by a resin like epoxy. It is common for laminates to fail because of delamination growth (plies peeling apart). Small delaminations do not …

Methods For The Aerostructural Design And Optimization Of Wings With Arbitrary Planform And Payload Distribution, Jeffrey D. Taylor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The design of an aircraft wing often involves the use of mathematical methods for simultaneous aerodynamic and structural design. The goal of many of these methods is to minimize the drag on the wing. A variety of computer models exist for this purpose, but some require the use of expensive time and computational resources to give meaningful results. As an alternative, some mathematical methods have been developed that give reason ably accurate results without the need for a computer. However, most of these methods can only be used for wings with specific shapes and payload distributions. In this thesis, a …

Characterization Of Carbon Nanostructured Composite Film Using Photothermal Measurement Technique, Kurt E. Harris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Graphene is a form of carbon with unique thermal and structural properties, giving it high potential in many applications, from electronics to driveway heating. Advanced fabrication techniques putting small, graphene-like structures in a polymer matrix could allow for incorporation of some of the benefits of graphene into very lightweight materials, and allow for broader commercialization. Measuring the thermal properties of these thin-film samples is a technical capability in need of development for use with the specific specimens used in this study. Relating those thermal properties to the microstructural composition was the focus of this work.

Several conclusions could be drawn …

A Propeller Model Based On A Modern Numerical Lifting-Line Algorithm With An Iterative Semi-Free Wake Solver, Zachary S. Montgomery

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A fundamental aerodynamic analysis technique for a single straight fixed wing has been expounded upon and turned into a modern technique that can analyze multiple wings of more realistic shapes common on aircraft. This modern technique is extended further to apply towards propellers. A method to overcome propeller analysis problems at low airspeeds is presented. This method is compared to more traditional propeller analysis techniques.

Distribution Of Particle Image Velocimetry (Piv) Errors In A Planar Jet, Jaron A. Howell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Particle Image Velocimetry (PIV) is an optical fluid measurement technique used to obtain velocity measurements. Two PIV systems were used to capture data simultaneously and measurement error for the MS PIV system is calculated. An investigation of error distribution is performed to determine when uncertainty estimations fail for the CS PIV-UQ method. Investigation of when results from multi pass PIV processing are achieve were performed so that reliable uncertainty estimations are produced with the CS method. An investigation was also performed which determined that error distributions in PIV systems are correlated with flow shear and particle seeding density. Correlation of …

Research Of A Non-Linearity Control Algorithm For Uav Target Tracking Based On Fuzzy Logic Systems, Chaoying Pei, Jingjuan Zhang, Xueyun Wang, Qian Zhang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Target tracking is one of the most widely used applications of UAVs and visual based tracking is the main method for non-cooperative tracking. In non-cooperative tracking missions, the UAV circles around the target and the gimbal rotates to keep the optic axis of the onboard camera pointing to the target. Compared with the biaxial gimbal, the single-axis gimbal system consists of only one torque motor, forming a great lightweight sensor suite, which also increases the requirement of the control accuracy. In the process of tracking moving target using a UAV with single-axis gimbal, there are still several challenges: (1) The …

Single-Stage, Venturi-Driven Desalination System, Brandon Proetto

Mechanical & Aerospace Engineering Theses & Dissertations

Water demand is increasing at a rapid pace due to population increase, industrial expansion, and agricultural development. The use of desalination technology to meet the high water demands has increased global online desalination capacity from 47 million m^3/d in 2007 to 92.5 million m^3/d as of June 2017 [49]. Membrane and thermal processes are the two mainstream desalination categories used worldwide for desalination plants. Reverse Osmosis (RO) is the most widely used membrane process and it has become the dominant technology for building desalination plants over recent decades. Thermal distillation, however, has become less and less competitive due to its …

Effect Of Cavitation Regimes On Stepped Diesel Injectors, David Michael Sykes

Theses and Dissertations

The objective of this work was to determine the effects of different cavitating flow regimes on a stepped orifice geometry relevant to diesel injectors. Conventional diesel orifice geometries consist of a single tapered or straight circular passage. The geometry used in this work had two circular passages in series: a first orifice that was similar to conventional geometries and a second larger orifice immediately downstream that induced cavitation. The large orifice served to stabilize the flow, allowing for different flow regimes to exist at the exit plane of the large orifice (single-phase, intermittent bubbly, bubbly, annular, etc.). A series of …

Second-Order Sensitivity Analysis Of Uncollided Particle Contributions To Radiation Detector Responses, Dan Gabriel Cacuci, Jeffrey A. Favorite

Faculty Publications

This work presents an application of Cacuci's Second-Order Adjoint Sensitivity Analysis Methodology (2nd-ASAM) to the simplified Boltzmann equation that models the transport of uncollided particles through a medium to compute efficiently and exactly all of the first- and second-order derivatives (sensitivities) of a detector's response with respect to the system's isotopic number densities, microscopic cross sections, source emission rates, and detector response function. The off-the-shelf PARTISN multigroup discrete ordinates code is employed to solve the equations underlying the 2nd-ASAM. The accuracy of the results produced using PARTISN is verified by using the results of three test configurations: (1) a homogeneous …

A High-Magnification Uv Lens For High-Temperature Optical Strain Measurements, Robert S. Hansen

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Digital Image Correlation (DIC) is an experimental method used to produce full-field strain maps of specimens undergoing deformation. In this measurement, images of a specimen are taken before and after mechanical and thermal loading, then software is used to track deformation and compute strains. DIC has been recently adapted for high-temperature tests by using ultraviolet (UV) range cameras, lenses, and filters to produce the images.

Application of DIC to small length scales and at high temperatures can be performed with proper equipment. However, for these measurements, there is no commercially available high-magnification lens that will allow images to be taken …

Fea Of Carbon Composite As A Substitute For Steel (A992) In Case Of Square Or Rectangular Hollow Cross-Sections As Beams And Columns, Pradeep Ganesh Pai

Mechanical and Aerospace Engineering Theses - Archive

Improvement to an existing design is an ongoing and never-ending process in every field. The improvement can be in a myriad of areas like an increase in strength, reduction in weight, stiffness to a loading condition and so on. The way it is achieved can range from changing the properties of the material used by incorporating various manufacturing processes or by using an alternative material which can sustain the same loading conditions or for that matter, work better than the existing material. Composite materials like Carbon Fiber, Glass Fiber or Kevlar Fiber reinforced plastics, to name few, are being used …

Cfd Analysis Of Resistance For Stepless And Stepped Planing Hulls, Bhanu Prakash Valtheru

Theses and Dissertations

It is the endeavour of naval architects to design hull forms with the least amount of power consumption. In this respect, Naval Architects have been obsessed with the design of various hull forms optimized for a particular service requiring the lowest amount of fuel consumption keeping in mind effects on the climate change and sustainability. Regardless of the way that a considerable measure of research has been done around this area, there remains a level of uncertainty in the reasonably accurate resistance prediction of stepped hull forms in the early design stage. Model tests and full-scale tests are still the …

Experimental And Numerical Comparison Of Wort Cooling Methods During The Homebrewing Process, Zachary Hammond

Renée Crown University Honors Thesis Projects - All

Homebrewing, the process of making beer for personal consumption, has been legal in the United States since 1978 and allowed beer enthusiasts to experiment with new beer styles at a low cost. Although the procedure is relatively straightforward, it can be very timeconsuming without expensive equipment. The longest step in brewing is wort cooling, where the non-alcoholic beer, or wort, is cooled from boiling temperatures to near room temperature for fermentation. Improper or slow cooling can not only be monotonous but result in contamination or haze in the final product. Wort chillers, which generally cost anywhere from $50 to $500, …

Stochastic Finite Element Thermal Analysis Of A Ball Grid Array Package, Rahul Upreti

Mechanical and Aerospace Engineering Theses - Archive

This study provides an insight into the factors which have a major impact on the probability of failure of a Ball Grid Array package. A stochastic finite element analysis was done on the package using First-order reliability method (FORM). The effects of uncertainty in material thermal conductivities, heat source, heat transfer coefficient and ambient temperature were studied. The average temperature at the die-junction interface was selected as failure criterion because the excess temperature at the junction is often a cause of failure. The performance of Finite Difference Method(FDM) and Semi-Analytic Complex Variable Method(SACVM) in computing sensitivities are compared. Results show …

Air Flow Pattern And Path Flow Simulation Of Airborne Particulate Contaminants In A Cold-Aisle Containment High-Density Data Center Utilizing Airside Economization, Gautham Thirunavakkarasu

Mechanical and Aerospace Engineering Theses - Archive

The energy used by Information Technology Equipment (ITE) and the supporting data center equipment keeps rising as data center expansion continues worldwide. To contain the rising operation costs, data center administrators are resorting to cost cutting measures by not adhering to the ambient data center environment standards. In many cases, free cooling techniques are adopted to partially or completely relieve the usage of refrigeration units, which adds to huge cost savings but also allows for the increased risk of particulate and gaseous contaminations. The ASHRAE TC9.9 subcommittee, on Mission Critical Facilities, Data Centers, Technology Spaces, and Electronic Equipment, has provided …

The Performance Of Quadrilateral Element With Rotational Degrees Of Freedom In Statics And Dynamics Analysis And Optimization, Xingzhi Wang

Mechanical and Aerospace Engineering Theses - Archive

Finite Element Method (FEM) is widely used in structural analysis, and the standard approach to increase the accuracy of analysis is increasing the total degrees of freedom (DOFs), namely, refine the mesh. By introducing the rotational DOFs, better accuracy can be achieved without change the mesh. The objective of this study was to investigate the performance of elements with rotational DOFs in statics and dynamics analysis and applying these elements to optimization. The implementation of three representative elements with rotational DOFs for statics analysis is reproduced. Also, this work implements these elements to dynamics analysis and optimization. The results show …

Computational Study Of Form Factor Of 3rd Generation Open Compute Servers Using Different Dielectric Fluids For Single-Phase Immersion Cooling, Pranavi Rachamreddy

Mechanical and Aerospace Engineering Theses - Archive

Computer system dependency has been increased in the modern world and that has encouraged the rapid growth of data centers in leading business units like banking, education, transportation, social media and many more. Data center is a facility that incorporates an organisation’s IT operations and equipment, as well as where it stores, processes, and manages the data. To fulfil the demands of data storage and data processing, corresponding increase in power density of servers are needed. The data center energy efficiency largely depends on the thermal management of servers. Currently, air cooling is the most widely used thermal management technique …

A New Adaptive Multiscale Approach For The Dynamic Modeling And Simulation Of Biomolecular Systems, Ashley Chase Guy

Mechanical and Aerospace Engineering Dissertations - Archive

This dissertation presents three developments in the simulation of sub-micron dynamical systems. First, a new thermostat formulation is shown to strictly enforce the constant temperature constraint necessary in many thermodynamic ensembles. This formulation also allows the system to quickly evolve to a low-potential state. Next, this new thermostat formulation is leveraged to extend a continuum-regime multiscale formulation to the atomistic regime allowing for equivalent time histories to be generated in significantly less computation time. Finally, an adaptive multiscale formulation allows for potential forces with time varying magnitudes to contribute to the overall dynamics similarly resulting in equivalent time histories in …

A Nanoindentation Study Of The Fatigue Properties Of Al/A-Si Core-Shell Nanostructures, Jason Steck

Mechanical Engineering Undergraduate Honors Theses

Nanostructure-textured surfaces can reduce friction and increase the reliability of micro- and nanoelectromechanical systems (NEMS/MEMS). For MEMS incorporating moving parts, the fatigue properties of nanostructures pose a challenge to their reliability in long-term applications. In this study, the fatigue behavior of hemispherical Al/a-Si core-shell nanostructures (CSNs), bare hemispherical Al nanodots, and a flat Al/a-Si layered thin film have been studied using nanoindentation and nano-scale dynamic mechanical analysis (nano-DMA) techniques. Fatigue testing with nano-DMA shows that the deformation resistance of CSNs persists through 5.0 × 10⁴ loading cycles at estimated contact pressures greater than 15 GPa. When the a-Si shell …