Engineering Commons^™

Anomaly Detection And Failure Prediction In Gas Turbines, Vipul Goyal

Electronic Theses and Dissertations, 2020-

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 …

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

Electronic Theses and Dissertations, 2020-

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-

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 …

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-

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 …

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

Electronic Theses and Dissertations, 2020-

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 …

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 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 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

Metal And Flexible Duct Systems Impacts Upon Cooling Energy And Performance, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

Flexible duct is commonly used throughout the U.S. in residential construction. It performs well when installed in accordance with industry standards, however, they are often not installed as such. Issues such as not cutting ducts to the exact length needed, and instead using significantly more duct, result in compression and higher static pressure. Poorly supported ducts or turns without proper radius also increase static pressure. A research project was completed to evaluate the differences in performance between a metal duct and flexible duct systems in two side-by-side otherwise identical residential laboratories. Testing evaluated three different flex duct system configurations compared …

On The Interaction Of Creep And High-Cycle Fatigue In Cm 247 Lc, Thomas Bouchenot

Electronic Theses and Dissertations, 2020-

Industrial gas turbines constitute a considerable portion of global power generation, from large engines for centralized grids, to smaller frames for decentralized demand. Power output, efficiency, and reliability are chief criteria regarding the development of next-generation turbines, whose components are expected to operate in ever harsher environments. Turbine blades are subjected to high temperatures, an array of mechanical loads, and dynamic fluid fields, all contained within a non-isothermal profile, making creep and high-cycle fatigue critical aspects of turbine blade design. Current analysis tools and methods have resulted in the development of many successful components; however, improved life prediction models with …

Exergoeconomic Analysis And Optimization Of Novel Cogeneration Systems For Freshwater Production, Power And Cooling, Sattam Alharbi

Electronic Theses and Dissertations, 2020-

Global consumption of energy and freshwater is increasing continuously due to population growth and improving living standards. The world energy consumption is anticipated to increase by around 50% by 2050 according to the U.S Energy Information Administration (EIA). There is also very limited access to freshwater and cooling in many developing countries. Therefore, developing an efficient energy system, recovering the waste heat (cogeneration system or multigeneration) to produce freshwater and cooling, and using a renewable energy source are promising solutions to meet the energy demand and to reduce environment pollution associated with fossil fuels. In this study, several novel cogeneration …

Experimental And Chemical Kinetics Investigation Of High-Temperature Combustion Of Diisopropyl Methylphosphonate., Ramees Khaleel Rahman

Electronic Theses and Dissertations, 2020-

Due to the high toxicity of chemical warfare (CW) agents, laboratory experiments are carried out using CW surrogates. Diisopropyl Methylphosphonate (DIMP), an organophosphate compound (OPC), is a crucial CW surrogate that has a chemical structure like the deadly nerve agent Sarin (GB). In this work, high-temperature combustion of DIMP is studied in a shock tube to understand the kinetics of destruction of DIMP. Laser absorption spectroscopy was used to obtain carbon monoxide mole fraction time-histories during high-temperature combustion of DIMP. Since combustion involves complex mixing phenomena involving different fuel to oxidizer ratios, experiments were conducted at conditions relevant to a) …

Signals As Symbols: Applying Normalization Of Deviance To Improve User-Centered Design, Amy Vanschaik

Electronic Theses and Dissertations, 2020-

Mistakes can happen in the process of designing and developing interactive digital projects. Sometimes these mistakes negatively impact users' perception and trust of digital interfaces. This research applies the concept of normalization of deviance to identify potential missed opportunities in user-centered design data within the context of a website redesign. By doing this I explore how through observing accidental deviant behaviors or processes we can identify ways to improve the usability and user experience of digital environments. I review the concepts of normalized deviant behavior as addressed by Diane Vaughan in the field of engineering and identify a process for …

Studies On Powder Compaction And Wire Extrusion Of Pure Metals And Metal/Cnt Nano Composites, Qiang Zhou

Electronic Theses and Dissertations, 2020-

The goal of this dissertation is to fabricate wires made of Cu/CNT and Al/CNT composites with good mechanical strength and super thermal/electrical conductivities using powder compaction and wire extrusion manufacturing processes. Powder compaction was studied using both test and simulation. Cold compaction, hot compaction and vibration assisted (cold) compaction tests were conducted to achieve different density ratios. Hot compaction tests improved about 6% compared with cold compaction under the same compression pressure. Although the relative density ratio does not obviously improve at vibration assisted (cold) compaction, the strength of the specimens made under vibration loading is much better than those …

Material Properties Of 17-4ph Stainless Steel Fabricated With Cooling Holes By Atomic Diffusion Additive Manufacturing (Adam), Nandhini Raju

Electronic Theses and Dissertations, 2020-

The objective of this study is to investigate the material properties of 17-4PH stainless steel printed with cooling holes in different build orientations by the Atomic Diffusion Additive manufacturing technique. Samples with film cooling holes printed in different build orientations, with impingement inserts, impingement cavities were manufactured in a Markforged Metal-X machine. The presence of the holes in these samples helps to understand the printability and accuracy of internal cooling holes, as manufactured by the Metal-X machine. Manufactured samples were first washed to remove the plastic binder. These pre-sintered samples were tested, for density, microstructure analysis, roughness, Energy Dispersive X-ray …

Corticomuscular Adaptation To Mechanical Perturbations In A Seated Locomotor Task, Seyed Yahya Shirazi

Electronic Theses and Dissertations, 2020-

Cortical control during walking is most pronounced when the person is perturbed. Although seated locomotor tasks such as cycling or recumbent stepping improve walking performance, the electrocortical correlates of perturbed seated tasks have not been studied in detail. The primary purpose of this research was to quantify cortical and muscular responses to mechanical perturbations during recumbent stepping. We also aimed to quantify possible differences between young and older adults' responses to perturbed stepping. A secondary aim of this research was to determine the accuracy of electroencephalography (EEG) source imaging to interpret the electrocortical findings adequately. We hypothesized that both young …

Damping And Ejection Of Sloshing Liquid Drops From Elastic Substrates, Md Erfanul Alam

Electronic Theses and Dissertations, 2020-

Liquid slosh is a potential source of disturbance of the motion of a moving structure. In this thesis, we probe the damping technique of sessile drop by absorbing a portion of the kinetic energy. The sloshing dynamics are typically represented by a mechanical model of a spring mass damper. However, damping by drop sloshing is dependent on viscosity, surface tension, drop size and drop location. We explore highly-coupled fluid-solid mechanics using singular liquid drop with varying viscosity and surface tension resting on a millimetric cantilever. Cantilevers are displaced 0.6 mm and their free end is allowed to vibrate freely. Cantilever …

Development And Characterization Of Flow Independent Fuel Injectors, Michael W. Kwara

Honors Undergraduate Theses

Jet-in-crossflow is an interaction between a fuel jet and air crossflow commonly found in jet engines. The crossflow is used to break up or atomize the fuel jet for downstream combustion. This interaction between fluids while at low speeds, is predictable, varies greatly at higher speeds. This investigation seeks to (1) create a mechanism for jet-in-crossflow, using mechanical pintles, that is independent of velocity to help increase the predictability and reliability of jet engines and (2) identify key design parameters that will lead to flow independence. Parameters investigated in this experiment include pintle height, angle, and percent of pintle coverage …

Fluid-Structure Interaction For A Deformable Anisotropic Cylinder: A Case Study, Jared T. Decker

Honors Undergraduate Theses

For a structure designed to interact with the surrounding fluid, structural deformation under loads induced by fluid flows is an important factor to consider, and one which is traditionally difficult to account for analytically. Coupling the finite element method for structural analysis with the finite volume method for the determination of fluid response allows for accurate simulation of the pressure and shearing loads applied by the fluid onto the fluid-structure interface, while also determining localized structural displacements that would cause changes to the geometry of the interface. This work seeks to simulate the behavior of cylinders with varying heights and …

Electromyographic And Mechanomyogrpahic Signal Changes With Fatigue In Adults, Rehana Koilpillai

Honors Undergraduate Theses

Surface electromyography (sEMG) and mechanomyography (MMG) are well-studied signals that can reveal information about the physiological behavior of muscles during contraction. The purpose of this study was to quantify, characterize, and analyze the electrical and mechanical muscle responses to submaximal, isometric contractions in the rectus femoris in adults. Previous studies have investigated the use of EMG to monitor muscle fatigue. However, more information appears to be needed about the use of MMG to measure muscle fatigue during submaximal isometric contraction in the rectus femoris. In this study, the utility of MMG as a measure of muscle fatigue or muscle state …

Heart Rate Variability In Adults During 24-Hours With A Focus On Sleep Period, Ankur Ravikanth

Honors Undergraduate Theses

The objective of this study is to investigate heart rate variability (HRV) over a period of 24 hours with special focus on patterns during the sleep period. Comparisons were made between sleep and the full 24-hour data. The Polar M430 watch was used to record heart rate (HR) data for about 24 hours, and the subject kept a journal of the activities they performed throughout the day. The data was visualized as heart rate in beats per minute (BPM) as a function of time. To check the accuracy of the Polar watch, a 7-minute recording of HR from the watch …

Flow Field Dynamics As A Result Of Perforated Plates, Hector Perez

Honors Undergraduate Theses

Detonation to Deflagration Transition (DDT) is the process of accelerating a laminar flame to supersonic speeds to cause a detonation. A method used to reach Chapman-Jouguet (CJ) detonation velocities is the induction of turbulence to increase the surface area of the flame front, increasing the consumption rate of unburned gases and the propagation speed of the flame. Perforated plates helped achieve flame acceleration in previous studies to induce turbulence when the flame front interacts with the turbulator; previous work also accomplished detonation speeds with perforated plates. This work aims to visualize the flame front and perforated plate interaction and analyze …

An Evaporation Based Micro-Synthetic Jet In Microchannel And Its Applications, Ehsan Sourtiji

Electronic Theses and Dissertations, 2020-

An approach to create synthetic jets at micro-scales using periodic bubble growth and collapse was presented and studied over a range of operating frequencies (0.1 to 2.5 Hz) and heating powers (3 to 4.5 Watt). The microfluidic device uses an interfacial layer between vapor and liquid phases which substitutes the requirement for a physical flexible membrane and any other moving parts. The bubble explosion and implosion in the chamber was triggered by periodically powering a micro-heater, which in turn generated the synthetic jet. High-speed camera photography and a microscope were used to capture sequential images of bubble nucleation, growth and …

Model-Form Uncertainty Quantification In Prognosis And Fleet Management With Physics-Informed Neural Networks, Arinan De Piemonte Dourado

Electronic Theses and Dissertations, 2020-

Prognosis and health management play an important role in the control of costs associated with the operation of large industrial equipment. By properly comprehending hardware degradation and accurately predicting the remaining useful life of such equipment, we can significantly lower operational costs by reducing asset downtime and maintenance interventions. However, complex interactions between operational conditions and component capability make accurately modeling damage accumulation for large fleets a daunting task. Unforeseen factors such as aggressive missions introduced by operators, exposure to harsh environments, manufacturing issues, amongst many others, can lead to large discrepancies between predicted and observed useful life. Motivated by …