Mechanical Engineering Commons^™

Design And Testing Of A Hybrid Direct Ink Writing And Fused Deposition Modeling Multi-Process 3d Printer, Alexander X. Losada

Honors Undergraduate Theses

Multi-material 3D Printing allows the ability to fabricate parts with tuned mechanical properties, multi-process 3D printing widens the choices of available fabrication materials. The objective of this study is to build a custom 3D printing test bed that is capable of printing multi-material parts with fused deposition modeling and direct ink writing techniques. A 3D printer, controlled by an industrial motion control system, with FDM and DIW capabilities was built by combining FDM extruders with a pneumatic dispensing system on a single platform. By utilizing the Direct Ink Writing function, we expand the number of printable materials to include some …

Quantitative Metallurgy Of Anisotropic Nickel-Base Superalloys Under Tensile And Fatigue Loading, Dominic Devito

Electronic Theses and Dissertations, 2020-2023

Nickel-base superalloys are ideal materials for application in high temperature and high stress environments. Their resistance to both heat and corrosion makes these metals well-suited for use as components in engines and turbines. There has been much interest in characterizing the mechanical properties of Ni-base superalloys under severe conditions. Either large monotonic loads or cyclic loads are the most investigated. Also, research efforts tend to focus on the influence of microstructural features of fatigue life, and they accomplish this through qualitative observation. Presented here is both quantitative and qualitative analysis done on Ni-base superalloy specimens that have been subjected to …

Synthesis, Characterization, And Modeling Of Thermo-Responsive Hydrogels With Improved Mechanical Strength And Swelling Kinetics, Marilu Ortiz Nieves

Electronic Theses and Dissertations, 2020-2023

Hydrogels have been extensively studied for use in applications such as tissue engineering, drug delivery systems, wound dressing, actuators, valves, and sensors in Micromechanical Systems (MEMS), among others. Thermo-responsive hydrogels in particular pose various advantages such as their capability to respond to an external stimulus and reverse the response when the stimulus is removed and the ability to imbibe a significant amount of solvent and increase their volume by over 1000%. Extensive research has been conducted to tune and improve hydrogel’s rate and degree of swelling and mechanical properties. Previous work showed that when synthetic clay (Laponite) is cross-linked with …

Crystal Viscoplastic Modeling Of Single Crystal And Directionally Solidified Nickel-Base Superalloys, Navindra Wijeyeratne

Electronic Theses and Dissertations, 2020-2023

Nickel-base superalloys (NBSAs) are widely used in engineering applications for many turbomachinery component designs. Superior material properties at high temperatures such as high tensile strength, superior fatigue strength, excellent resistance to thermal shocks, and strong corrosion resistance are primarily responsible for their extensive application. This proposal focuses on modeling generic single crystal (SX) and directionally solidified (DS) Ni-base superalloy. Compared to polycrystal superalloys, SX superalloys exhibit superior thermal fatigue and creep resistance which is attributed to the absence of grain boundaries in the SX crystalline structure. Directional solidification procedures enable the solidification structure of the materials to be comprised of …

Lithium-Ion Battery Prognosis With Variational Hybrid Physics-Informed Neural Networks, Renato Giorgiani Do Nascimento

Electronic Theses and Dissertations, 2020-2023

Lithium-ion batteries are an increasingly popular source of power for many electric applications. Applications range from electric cars, driven by thousands of people every day, to existing and future air vehicles, such as unmanned aircraft vehicles (UAVs) and urban air mobility (UAM) drones. Therefore, robust modeling approaches are essential to ensure high reliability levels by monitoring battery state-of-charge (SOC) and forecasting the remaining useful life (RUL). Building principled-based models is challenging due to the complex electrochemistry that governs battery operation, which would entail computationally expensive models not suited for prognosis and health management applications. Alternatively, reduced-order models can be used …

Heat Transfer Characterization Of Carbon Dioxide In Micro Impinging Jet(S) Near Critical Conditions, Stephen Adeoye

Electronic Theses and Dissertations, 2020-2023

The continuous growth and demand of increased operating performances of electronics has brought about an increase in the chip power density posing threat to the thermal management of these devices. Although numerous thermal solutions ranging from passive to active cooling together with a variety of working fluids have been adopted, however, the question whether these available cooling methods could meet up with the ever-growing need for increased operating performances is a concerning one. Jet impingement cooling has been effectively used in many industrial applications due to its high heat transfer capability. The limited study at the micro scale suggests that …

Numerical Study Of Flow Of Supercritical Carbon Dioxide Inside Microchannels With Heat Transfer, Uday Manda

Electronic Theses and Dissertations, 2020-2023

Heat transfer inside microscale geometries is a complex and a challenging phenomenon. As supercritical fluids display large variations in their properties in the vicinity of the critical point, their usage could be more beneficial than traditional coolants. This numerical study, in two parts, primarily focuses on the physics that drives the enhanced heat transfer characteristics of carbon dioxide (CO2) near its critical state and in its supercritical state. In the first part of the study, the flow of supercritical Carbon Dioxide (sCO2) over a heated surface inside a microchannel of hydraulic diameter 0.3 mm was studied using three-dimensional computational fluid …

Decentralized Digital Fabrication Of Flexible Micro/Nano Devices Using A Laserjet Printer, Arshya Bamshad

Electronic Theses and Dissertations, 2020-2023

The fabrication of traditional micro/nano devices requires access to cleanrooms, complex and expensive tools, and highly-skilled labor. A facile and digital do-it-yourself (DIY) technique for the fabrication of low-cost devices on flexible substrates (paper, cloth, and plastic films) is presented in this work. A set of office-grade equipment (i.e., laserjet printer, thermal laminator, computer-aided paper cutter), and commercially available supplies (i.e., baking wax paper, furniture restoration metal-leaf) are utilized. The presented technology enables community-embedded production by removing a high technological barrier. The validity of the proposed technology was proved by designing three levels of experiments, i.e., patterns, devices, and systems. …

Investigating Ground Interactions Of A Rotocraft Landing Vehicle On Titan, Adam Rozman

Honors Undergraduate Theses

The exploration of celestial bodies has recently advanced from rovers to rotorcraft. This includes the recent flights of Mars Ingenuity and the upcoming Dragonfly mission to explore the terrain of Saturn’s moon Titan as part of NASA’s New Frontiers Program. Flight-based landers can travel quickly to sites kilometers apart and land in complex terrain. Although cruise conditions for these rotorcrafts are well understood, studies are necessary to understand take-off and landing. In ground effect conditions, a rotor wake impinges and reflects off the ground, creating changes in aerodynamics such as increased lift. Additionally, operating over loose surfaces, the rotors can …

Autoignition Delay Time Measurements And Chemical Kinetic Modeling Of Hydrogen/Ammonia/Natural Gas Mixtures, Jessica Baker

Electronic Theses and Dissertations, 2020-2023

In recent years, hydrogen-carrying compounds have accrued interest as an alternative to traditional fossil fuels due to their function as zero-emission fuels. As such, there is interest in investigating hydrogen-carrying compounds to improve understanding of the fuels' characteristics for use in high pressure systems. In the current study, the oxidation of ammonia/natural gas/hydrogen mixtures was carried out to study CO formation profiles as well as the ignition delay times behind reflected shock waves in order to refine chemical kinetic models. Experiments were carried out in the University of Central Florida's shock tube facility by utilizing chemiluminescence to obtain OH* emission …

Prediction And Validation Of Residual Stresses In Additively Manufactured Metal Parts, Jose Mayi Rivas

Electronic Theses and Dissertations, 2020-2023

Selective Laser Melted (SLM) Additively Manufactured (AM) metal parts are of special interest to many industries because their designs can be made arbitrarily complex while still maintaining bulk type mechanical properties. However, the large thermal gradients inherent to the SLM process generate residual stresses (RS) and distortions that are detrimental to the fit, functionality and integrity of parts. Predicting the state of stresses in as-built 3D printed parts is a difficult problem that currently has only been approached with the use of transient thermomechanical Finite Element Models (FEMs). The nonlinearities associated with AM processes are difficult to capture in these …

Generative Adversarial Networks For Extrapolation Of Corrosion In Automobile Images, Andre Von Zuben

Electronic Theses and Dissertations, 2020-2023

Deep learning has shown success in several applications involving pattern recognition, expert systems, and scientific discovery. However, existing methods struggle with industrial applications, which are often challenged by non-ideal datasets. In many cases, the datasets are small, poorly labeled, noisy, or have unbalanced class distribution or any combination of such problems. In this Master's research, we propose a generative adversarial network (GAN) strategy that is able to circumvent limitations imposed by tiny datasets. As a case study, we use the extrapolation of corrosion in automobiles and feed our deep learning framework with only a few dozen images instead of the …

Simulation Of A Comprehensive Heat Recovery Steam Generator, Jose Chalarca Castro

Electronic Theses and Dissertations, 2020-2023

With the increasing prevalence of renewables, it is important to optimize combined cycle power plants during transient conditions to better compliment the variable generation of renewable energy generators. There is a demand for dynamic heat recovery steam generators (HRSG) models that may enable improved control designs. Sufficiently accurate real-time simulations of HRSGs may serve as soft sensors and state estimators during transient conditions. Furthermore, real-time simulations of HRSGs can be used for operator training which does not incur the inherit risk of using plant hardware. The focus of this research is on the development towards an integrated dynamic closed loop …

The Fluid Dynamics Of A Spanwise-Morphing Wing: An Experimental And Analytical Study, Kamlesh Joshi

Electronic Theses and Dissertations, 2020-2023

The unsteady forces and fluid flow structure of a morphing wing are investigated for low Reynolds number (Re) flows, i.e., Re < 20,000. The morphing wing is designed to change shape in the spanwise direction in a controlled manner using internal actuation. The two types of wing morphing are studied in this work, i.e., spanwise bending and spanwise twisting. The wing morphing is named based on the overall shape of the wing after it is dynamically morphed.

Non-Invasive Detection Of Elevated Intracranial Pressure Using Spontaneous Tympanic Membrane Pulsation, Rajkumar Dhar

Electronic Theses and Dissertations, 2020-2023

Monitoring intracranial pressure (ICP) is a standard diagnostic tool for various neurological conditions such as head injury, ruptured aneurysms, intracerebral and intracranial hemorrhage, and hydrocephalus. Currently, ICP monitoring relies on invasive pressure measurements. These include intraventricular catheter, subdural screw, epidural sensor, and lumbar puncture. Invasive methods pose the risk of infection and hemorrhage, are expensive, and require special clinical skills. A noninvasive method that is reliable, simple to use, low-cost, and provides easily interpretable results can help avoid the complications associated with the invasive methods. This study proposes a novel method for noninvasive ICP monitoring using tympanic membrane pulsation (TMp). …

A Flexible 3d Architecture For Cooling Future Generation Devices, Khan Mohammad Rabbi

Electronic Theses and Dissertations, 2020-2023

Systems that consume and convert energy produce thermal energy as a byproduct. This generation of thermal energy, if not dissipated properly, contributes to the significant temperature rise of the overall system. This temperature rise can lead to reduced efficiency and system-level failure. Future technologies will continue to face such thermal challenges. In fact, next-gen devices will demand flexible thermal management architectures for high-performance operation. To tackle these challenges, innovative liquid cooling technologies and high-speed thermal diagnostic systems must be developed simultaneously. Active and passive pulsation-liquid-cooling techniques are currently an attractive thermal management solution. In an active cooling mode, the influence …

A Framework For The Design And Characterization Of Advanced Gaskets, Sannmit Shinde

Electronic Theses and Dissertations, 2020-2023

Most industrial manufacturing or processing plants use bolted connections between pipes that transfer media from one location to another. Gaskets are often used to seal these systems as they offer elevated levels of leak mitigation; however, despite their nearly universal usage, the current understanding of gasket mechanics at the meso-scale is still limited. Contemporary gaskets feature viscoelastic materials, fillers, textures, and are fabricated at various thicknesses. They are used in a wide range of thermal, mechanical, chemical, and temporal conditions. The current work characterizes polytetrafluoroethylene (PTFE) gaskets made with several different filler materials and having vastly different geometries. The chemically …

Anomaly Detection And Failure Prediction In Gas Turbines, Vipul Goyal

Electronic Theses and Dissertations, 2020-2023

This study is based on time-series data taken from the combined cycle heavy-duty utility gas turbines. For analysis, first, a multi-stage vector autoregressive model is constructed for the nominal operation of powerplant assuming sparsity in the association among variables, and this model is used as a basis for anomaly detection and prediction. This prediction is compared with the time-series data of the powerplant test data containing anomalies. Granger causality networks, which are based on the associations between the time series streams, can be learned as an important implication from the vector autoregressive modelling. This method suffers from the disadvantage that …

Tailoring Of The Left Ventricular Assist Device Cannula Implantation Using Coupled Multi-Scale Multi-Objective Patient Specific Optimization., Abubakar Dankano

Electronic Theses and Dissertations, 2020-2023

Despite advancements in device design and anti-coagulation treatments, there are numerous adverse events that may occur following implantation of LVADs. The most devastating involves the embolization of thrombus into the brain causing a stroke, with incidence of up to 14-47% over a 6–12-month period. This study aims to elucidate ways to reduce this risk by surgical maneuvers guided by a multi-scale computational fluid dynamics analysis wrapped around a multi-objective shape optimization scheme which optimizes the anastomosis location of the VAD outflow graft (OG) along the ascending aorta to minimize the incidence of thrombi reaching the cerebral vessels and reduce particle …

Topology Optimization Of Internal Cooling Channels In Turbulent Flows, Shinjan Ghosh

Electronic Theses and Dissertations, 2020-2023

Topology optimization, introduced by Bendsoe and Sigmund in 1988 has been a topic of research in the structural mechanics field for several decades. This technique is commonly used to optimize system performance of structural components with minimum material usage by varying the distribution of materials in a given domain. Fluid dynamic topology optimization, a relatively new research topic uses a method of adding or subtracting materials to a given flow domain to obtain an optimal flow-path for a given objective function. While the structural TO creates a solid structure by introducing holes into the domain, fluid TO introduces solid into …

Synthesis And Assessment Of Sustainable Fuels For Transportation And Space Exploration, Katerina Chagoya

Electronic Theses and Dissertations, 2020-2023

As global energy sources transition towards renewable energy, the demand for sustainable fuels has never been greater. The sheer scale of this transition will require numerous solutions to accommodate for the diverse and complex situations worldwide. This dissertation will discuss 3 studies: the utilization of CO2 waste gas to produce fuels sustainably, characterizing biofuels for efficient use in automobiles, and developing a solid, emissonless fuel intended for spaceflight but also applicable on Earth. The hydrogenation of CO2 into value-added molecules could reduce greenhouse gas emissions if waste stream CO2 were captured for conversion. We found that atomic vacancies induced in …

Connected Water Heater Load Shifting And Energy Efficiency Evaluation For The Southeast: Winter Laboratory Assessment, Final Report, Florida Solar Energy Center, Karen Fenaughty

FSEC Energy Research Center®

The University of Central Florida's FSEC Energy Research Center (FSEC) and Pacific Northwest National Laboratory (PNNL) are conducting laboratory electrical load shifting experiments using the CTA-2045-A standard to demonstrate the viability of grid-connected heat pump water heaters (HPWH), compared to electric resistance water heaters (ERWH), in providing load shifting in the Southeastern United States (U.S.). The investigation applied different CTA-2045 shed and critical peak (CP) control command designs under two different water draw profiles. The highly-controlled laboratory experiments were conducted on four HPWHs and one ERWH from December 2020 through February 2021.

The research aimed to evaluate the load shifting …

Comparison Of The Residential Provisions Of The 7th Edition (2020) Florida Building Code, Energy Conservation With The 2021 Iecc, Florida Solar Energy Center, Jeffrey Sonne

FSEC Energy Research Center®

This report provides a comparison between the 7th Edition (2020) Florida Building Code, Energy Conservation (FBC-EC) and 2021 International Energy Conservation Code (IECC), based on approved 2018 to 2021 IECC changes included in the International Code Council's Complete Revision History to the 2021 I-Codes document. The first part of this study involved developing code change listings based on the Revision History document that identify changes that have potential energy and cost impacts. This second part of the study provides a stringency evaluation and cost-benefit analysis for those changes that impact energy use, to provide guidance for the upcoming 2020 FBC-EC …

Comparison Of The Commercial Provisions Of The 2020 Florida Building Code, Energy Conservation, 7th Edition With 2021 Iecc & Ashrae 90.1-2019, Florida Solar Energy Center, Bereket Nigusse

FSEC Energy Research Center®

This report provides comparison of the commercial provisions of the 7th Edition (2020) Florida Building Code, Energy Conservation (FBC-EC) with the 2021 International Energy Conservation Code (IECC) and ASHREA 90.1-2019. The first part developed code changes listing identifying energy and construction cost impacts. The second part analyzed energy and energy cost savings potential of the 2021 IECC and the 2019 ASHRAE 90.1 compared to the 2020 FBC-EC using prototype buildings energy model and simulation. And performed cost-benefit analysis of code changes with energy impact and provided recommendation for consideration by Florida Building Commission for addition to the 8th Edition (2023) …

Mitigation Of Airborne Contaminant Spread Through Simple Interventions In An Occupied Single-Family Home, Florida Solar Energy Center, Nazim Muradov

FSEC Energy Research Center®

Historically, reducing aerosol-based transmission of respired viruses in indoor environments has been of importance for controlling influenza viruses and common-cold rhinoviruses. The present public health emergency associated with SARS-CoV-2 makes this topic critically important. Yet to be tested is the potential effectiveness of simple interventions that create an isolation zone (IZ) for a suspected/confirmed sick or sensitive person requiring quarantine. The intent in existing homes is to find a practical means to mitigate exposure to airborne contaminants. In creating an IZ in an occupied single-family home in the study, four simple strategies were tested. The test configurations were: (1) IZ …

Lab Home Testing Of Residential Isolation Space Control To Minimize Infectious Disease Transmission In Existing Single-Family Homes, Florida Solar Energy Center, Tanvir Khan

FSEC Energy Research Center®

Existing evidence strongly suggests that viral infectious diseases can be transmitted via an airborne route across distances in indoor environments. Accordingly, the risk of airborne transmission within homes should be managed. The public health emergency associated with SARS-CoV-2 makes controlling airborne transmission of respired viruses in indoor environments critical, especially in poorly ventilated indoor environments. The effectiveness of engineering interventions requiring minor efforts that create a negative-pressure isolation zone (IZ) for a contagious person has yet to be tested for existing residential homes.

To mitigate the risk of airborne virus transmission and maximize health protection for the population in existing …

Lab Home Testing Of Residential Isolation Space Control To Minimize Infectious Disease Transmission In Existing Single-Family Homes - Fact Sheet, Florida Solar Energy Center, Tanvir Khan

FSEC Energy Research Center®

The FSEC Energy Research Center at the University of Central Florida performed research to test the effectiveness of interventions to isolate an ill person recovering from a contagious disease in a single-family home from the rest of the occupants in the home. Focus was placed on interventions requiring minor cost and effort on the part of the occupants.

DOE/GO-102021-5537, https://www.nrel.gov/docs/fy21osti/79519.pdf

Survey Of Unvented Attics In Climate Zone 2a, Florida Solar Energy Center, Eric Martin

FSEC Energy Research Center®

Moisture risk must be managed in unvented attics to ensure durability of components and longevity of the system. The FSEC Energy Research Center (FSEC), at the University of Central Florida tested and collected data in six homes in the northern Florida portion of IECC Climate Zone 2A built after 2015 with unvented (semi-conditioned) attics to add to the body of knowledge on the accumulation of moisture in the attic and its effects on roof moisture that can impact durability.

Relative International Energy Conservation Code (Iecc) Energy Impacts By Compliance Path, Florida Solar Energy Center, Philip W. Fairey

FSEC Energy Research Center®

The EnergyGauge® USA (v.6.2) residential building energy simulation software tool is used to examine energy impacts in two-story, 2,376 ft², single-family homes configured in accordance with the minimum requirements of Section R402-R404 of the 2018 IECC in fourteen representative U.S. cities.⁴ EnergyGauge USA is a RESNET-accredited HERS software tool capable of evaluating not only the HERS Index and the IECC Section R406 Energy Rating Index Compliance Alternative but also the IECC Section R405 Simulated Performance Alternative as well as the IECC Section R402 R-Value and Total UA Alternative prescriptive methods along with all of the IECC mandatory …

Resilient Florida Buildings: Alternative Fuel Options For Maintaining Power During Outages, Brochure, Florida Solar Energy Center, Colleen Mccann Kettles

FSEC Energy Research Center®

Electricity outages impact buildings as well as the fueling infrastructure that delivers energy resources for power generation and transportation. A fueling infrastructure with minimal downtime during power outages is needed to increase the resiliency of buildings and the economy. This brochure describes alternative fuels to consider for a buildings resiliency plan. This material is based upon work supported by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE) under the Energy Technology Development Program Award Number DE-EE0008880. FSEC Art#: BLDG-89 Updated: 05/20/2021