Mechanical Engineering Commons^™

The Capabilities And Limitations Of Flywheel-Based Energy Storage System Pertaining To Subways In The Event Of A Power Outage, Jaskaran Singh

Dissertations and Theses

In the city that never sleeps, power outages or blackouts can be a shock, especially if you are on a train amid one. For example, during the infamous 2003 blackout, thousands of people were left stuck and stranded in parts of Northeastern United States. In particular, with no trains or buses in service throughout the 5 boroughs of NYC, those stranded essentially had no way to go back home. Hotels, terminals, and airports alike became places of camping as the city seemed to come to a halt. For the sake of public safety and transit efficiency, this study explores a …

The Impact Of Covid-19 On Building Energy Consumption In New York City, Martha A. Olaleye

Dissertations and Theses

Since February 2020, the spread of COVID-19 affected the world economy, with the population of people contacting the virus in New York City at that time being at the highest in the United States of America. Thus, the need for remote/online learning was adopted for the safety of faculty, staffs, and students of New York Educational institution like CCNY. In the study, I focused on energy consumption as regards to COVID and POST-COVID periods in New York City (NYC), since most employees are working from home and schools are online which implies that most commercial buildings are vacant. Also due …

Analysis Of Bio-Alcohols With Mie-Scattering And Ltc For Lowered Emissions In Pcci, Cesar E. Carapia

College of Graduate Studies: Theses & Dissertations

An investigation was conducted on the optimal engine parameters for facilitating lower NOX and soot emissions of PCCI combustion with either ethanol or n-butanol. The PFI fuels selected were tested at loads of 3, 4, and 5 Bar IMEP for a total of 28 total combustion tests with variations made to the EGR% and boost pressure for each test in order to find the optimal emissions strategy. A Mie-scattering spray fuel analysis was also conducted on the three fuels to gain insight on their influence on combustion/emissions characteristics. It was found that ethanol had a greater average Sauter Mean Diameter …

Controlling The Thermal And Electrical Properties Of Camno3-Δ Based Perovskite Ceramics, Sergio Andres Paredes Navia

Graduate Theses, Dissertations, and Problem Reports (ETD)

Most of the energy lost during the conversion process comes in the form of waste heat. The world's energy consumption loses over 60% of its energy after conversion. In order to increase the efficiency of the conversion process, it is essential to harness waste heat and reutilize this energy resource. Heat recovery technology as thermoelectric (TE) technology is one of the growing alternatives to harvest excessive amounts of energy lost as waste heat for a more efficient, safe, and sustainable future. Due to the Seebeck effect, TE materials have the potential to convert waste heat directly into electricity, improving efficiency …

Development Of Phase Change Thermal Storage Medium: Cooking With More Power And Versatility, Martin Osei

Masters Theses

With an Insulated Solar Electric Cooker (ISEC), a 100 W solar panel directly cooks food while providing 5W off-grid electricity access; but it cooks slowly. Storing the day’s energy with phase change thermal storage allows ISEC to cook more rapidly as well as cook after sunset. The ISEC is made by sticking a 3ohm resistive to an aluminum pot (inner phase change assembly PCA) where another cooking pot fits. The resistive heater is surrounded by a bigger pot (outer PCA) that contains the PCM and is tightly sealed. The solar panel is connected to the resistive heater with a thermal …

High Energy And Power Density Peptidoglycan Musclesthrough Super-Viscous Nanoconfined Water, Haozhen Wang, Zhi-Lun Liu, Jianpei Lao, Sheng Zhang, Rinat Abzalimov, Tong Wang, Xi Chen

Advanced Science Research Center

Water-responsive (WR) materials that reversibly deform in response to humidity changes show great potential for developing muscle-like actuators for miniature and biomimetic robotics. Here, it is presented that Bacillus (B.) subtilis’ peptidoglycan (PG) exhibits WR actuation energy and power densities reaching 72.6 MJ m−3 and 9.1 MW m−3, respectively, orders of magnitude higher than those of frequently used actuators, such as piezoelectric actuators and dielectric elastomers. PG can deform as much as 27.2% within 110 ms, and its actuation pressure reaches ≈354.6 MPa. Surprisingly, PG exhibits an energy conversion efficiency of ≈66.8%, which can be attributed to its super-viscous nanoconfined …

Combustion Feature Characterization Using Computer Vision Diagnostics Within Rotating Detonation Combustors, Kristyn B. Johnson May

Graduate Theses, Dissertations, and Problem Reports (ETD)

In recent years, the possibilities of higher thermodynamic efficiency and power output have led to increasing interest in the field of pressure gain combustion (PGC). Currently, a majority of PGC research is concerned with rotating detonation engines (RDEs), devices which may theoretically achieve pressure gain across the combustor. Within the RDE, detonation waves propagate continuously around a cylindrical annulus, consuming fresh fuel mixtures supplied from the base of the RDE annulus. Through constant-volume heat addition, pressure gain combustion devices theoretically achieve lower entropy generation compared to Brayton cycle combustors. RDEs are being studied for future implementation in gas turbines, where …

Cfd And Heat Transfer Analysis Of Rocket Cooling Techniques On An Aerospike Nozzle, Geoffrey Sullivan

College of Graduate Studies: Theses & Dissertations

In recent years the development of rocket engines has been mainly focused on improving the engine cycle and creating new fuels. Rocket nozzle design has not been changed since the late 1960s. Recent needs for reliable and reusable rockets, as well as advancements in additive manufacturing, have brought new interest into the aerospike nozzle concept. This nozzle is a type of altitude adjusting nozzle that is up to 90% more efficient than bell nozzles at low altitudes and spends up to 30% less fuel. Since the nozzle body is submerged in the hot exhaust gasses it is difficult to keep …

Tidal Current Turbine Blade Optimisation With Improved Blade Element Momentum Theory And A Non-Dominated Sorting Genetic Algorithm, Eng Jet Yeo, David Kennedy, Fergal O'Rourke

Articles

Tidal current energy has the advantage of predictability over most of the other renewable energy resources. However, due to the harsh operating environment and complicated site conditions, developments in this domain have been gradual. Paramount to these points is device design and optimisation of hydrodynamic performance. Recent developments in the correction models of BEM theory have further improved the accuracy of the prediction model. Using an improved blade element momentum theory model that is capable of accurately capturing the downwash angle and combining it with a well-developed and reliable non-dominated sorting genetic algorithm model, an effective and efficient tidal current …

Building Performance - Societal Drive, Programme And Symposium, Joseph Little, Patrick Daly

Articles

Society is increasingly looking at the construction industry to mitigate the environmental crisis and solve the housing crisis through wholesale embrace of three broad sets of challenges. The MSc in Building Performance (Energy Efficiency in Design) (MSc BP(EED)) was created in 2017 to provide significant upskilling in the knowledge, skills, and software applications of building design professionals so that they can meet these challenges, while creating compliant, sustainable, super-low energy, new and renovated buildings. The delivery of the programme supports upskilling of employed building design professionals at Masters level, encouraging a minority to develop their capacity and interest in research …

Analysis Of Emissions Profiles Of Hydraulic Fracturing Engine Technologies, Nicholas Joseph Wells

Graduate Theses, Dissertations, and Problem Reports (ETD)

In the past twenty years natural gas production in the United States has significantly increased. This is largely due to technological advancements in unconventional methods of horizontal drilling and hydraulic fracturing. With these new and improved technologies, the United States has been able to increase its natural gas dry production per year by 14.5 trillion cubic feet per year from 2001-2021, a 74.1% increase. Horizontal drilling allows the wellbore to have more contact with the source rock, thus allowing more hydrocarbons to be extracted. Hydraulic fracturing allows oil and gas companies to have access to low permeable source rock, previously …

Development Of Methane Emissions Model To Assess Fuel Recovery Potential At Gas Well Sites Using On Site Compression, Nicholas G. Lindenfeldar

Graduate Theses, Dissertations, and Problem Reports (ETD)

The US natural gas production and consumption has increased 85.5% since 2005 primarily due to the unconventional production methods of horizontal drilling and hydraulic fracturing. Natural gas used as a fuel has a lower greenhouse gas (GHG) footprint than coal and petroleum due to lower Carbon Dioxide (CO₂) emissions when combusted. However, the “greener” benefit to natural gas may be consumed by leaks in production and transmission systems. Methane (CH₄), the primary hydrocarbon in natural gas, has an estimated Global Warming Potential (GWP) of 28-36 over 100 years, meaning it can absorb 28-36 more energy than …

Development Of A Thermal Desalination System Using Low Quality Thermal Energy, Takudzwa C. Chipunza

Graduate Theses, Dissertations, and Problem Reports (ETD)

Abstract

Development of a Thermal Desalination System Using Low Quality Thermal Energy

Takudzwa Chipunza

The blowdown water from the cooling tower of the power plant and the produced water from shale gas industry cannot be disposed directly to the environment as they may contain dissolved solids that are harmful to the environment. A detailed physical and chemical process to remove the mineral and organic solids has been developed in West Virginia University. Such a process includes running the blowdown and produced water through a softening tank, activated carbon tank, and a reverse osmosis (RO) system. The RO reject contains a …

Computational Analysis Of The Stability Limits Of Premixed Methane-Air Combustion In Micro-Channels, Almoutazbellah Adnan Kutkut

Graduate Theses, Dissertations, and Problem Reports (ETD)

Technological progress in the last decades facilitated the development of integrated microsystem devices, including electrical and mechanical components for micro-electro-mechanical systems (MEMS). Such systems necessitate an external power supply, but typical batteries yet have some unavoidable limitations. To address this problem, numerous studies have been conducted to develop alternatives powered by micro combustion – in order to effectively utilize the high-density energy of hydrocarbon fuels. Such a global need has resulted in much more attention devoted to the combustion-based micro-power generation systems. However, to better understand the typical combustion characteristics in such microscale systems, design and performance restrictions need to …

Model Predictive Control Of Energy Systems For Heat And Power Applications, Chethan Ramakrishna Reddy

Dissertations, Master's Theses and Master's Reports

Building and transportation sectors together account for two-thirds of the total energy consumption in the US. There is a need to make these energy systems (i.e., buildings and vehicles) more energy efficient. One way to make grid-connected buildings more energy efficient is to integrate the heating, ventilation and air conditioning (HVAC) system of the building with a micro-scale concentrated solar power (MicroCSP) sys- tem. Additionally, one way to make vehicles driven by internal combustion engine (ICE) more energy efficient is by integrating the ICE with a waste heat recovery (WHR) system. But, both the resulting energy systems need a smart …

Development Of Advanced Models For Pre-Ignition Prediction In Gas Engines And Analytical Model For Wallfilm Evaporation, Ankith Ullal

Dissertations, Master's Theses and Master's Reports

Ever-changing regulations aimed at improving efficiency and reducing harmful emissions have resulted in many power-generation device (engine) manufacturers to adopt new strategies. Computer simulation of these new strategies of power generation requires more accurate and higher fidelity modelling tools. In the present study, two such models are developed. The first model deals with pre-ignition phenomena driven by lubricant (lube) oil in natural gas engines and the second model is relevant to prediction of wallfilm evaporation by employing analytical solutions to transport governing equations for boundary layers.

Pre-ignition in engines has been the subject of current research with the advent of …

Partially Stratified Combustion Of Natural Gas For Spark Ignition Engines, Philip S. Zoldak

Dissertations, Master's Theses and Master's Reports

In this work, the advantages of partially stratified direct injection natural gas versus premixed port-fueled injection natural gas spark ignited engines has been studied. The volumetric efficiency, ratio of specific heats and turbulent kinetic energy was found to be higher with direct injection versus port-fueled injection thus improving thermal efficiency. A background study of optical chamber experimental data was performed to develop an understanding on the effect of pressure ratio on direct injection of methane under both fully-expanded (sub-sonic) and under-expanded (super-sonic) conditions. Under-expanded jets had a noticeable advantage in terms of turbulent kinetic energy, which led to enhanced air …

Optimal Control Of Nonlinear Wave Energy Converters In Heave For Maximum Power Extraction, Kevin Nelson

Dissertations, Master's Theses and Master's Reports

The marine renewable energy community is interested in maximizing the power generated by nonlinear wave energy converters. Optimal control methods provide a tool to achieve this aim and can also help to inform the buoy design. An energy-optimal control law for a class of non-linear buoy models is derived and is shown to be singular. The solution approach is illustrated using an hourglass-shaped buoy having a cubic, hydrostatic nonlinearity. The optimal control law is only valid on singular arcs, and a method to search for these arcs is presented. Two singular arcs are found for the hourglass buoy model and …

Electro-Chemo-Mechanics Of The Interfaces In 2d-3d Heterostructure Electrodes, Vidushi Sharma

Dissertations

Unique heterostructure electrodes comprising two-dimensional (2D) materials and bulk three dimensional (3D) high-performance active electrodes are recently synthesized and experimentally tested for their electrochemical performance in metal-ion batteries. Such electrodes exhibit long cycle life while they also retain high-capacity inherent to the active electrode. The role of 2D material is to provide a supportive mesh that allows buffer space for volume expansions upon ion intercalation in the active material and establishes a continuous electronic contact. Therefore, the binding strength between both materials is crucial for the success of such electrodes. Furthermore, battery cycles may bring about phase transformations in the …

Energy Planning Model Design For Forecasting The Final Energy Consumption Using Artificial Neural Networks, Haidy Eissa

Theses and Dissertations

“Energy Trilemma” has recently received an increasing concern among policy makers. The trilemma conceptual framework is based on three main dimensions: environmental sustainability, energy equity, and energy security. Energy security reflects a nation’s capability to meet current and future energy demand. Rational energy planning is thus a fundamental aspect to articulate energy policies. The energy system is huge and complex, accordingly in order to guarantee the availability of energy supply, it is necessary to implement strategies on the consumption side. Energy modeling is a tool that helps policy makers and researchers understand the fluctuations in the energy system. Over the …

Solution-Processed Flexible Broadband Zno Photodetector Modified By Ag Nanoparticles, N. P. Klochko, K. S. Klepikova, I. V. Khrypunova, V. R. Kopach, I. I. Tyukhov, S. I. Petrushenko, S. V. Dukarov, V. M. Sukhov, M. V. Kirichenko, A. L. Khrypunova

Faculty Research, Scholarly, and Creative Activity

In this work, we present flexible broadband photodetectors (PDs) fabricated by a deposition of nanostructured zinc oxide (ZnO) films on polyimide (PI) substrates by using cheap and scalable aqueous method Successive Ionic Layer Adsorption and Reaction (SILAR). In order to increase the long-wavelength absorption of the nanostructured ZnO layer, we created its intrinsic defects, including oxygen vacancies by post-treatment at 300 °C in vacuum and thus the light-sensitive material ZnO/PI was obtained. Then we applied silver nanoparticles (Ag NPs) from a silver sol onto a nanostructured ZnO film, which were visualized using SEM in the form of spheres up to …

Torque Vectoring To Maximize Straight-Line Efficiency In An All-Electric Vehicle With Independent Rear Motor Control, William Blake Brown

Theses and Dissertations

BEVs are a critical pathway towards achieving energy independence and meeting greenhouse and pollutant gas reduction goals in the current and future transportation sector [1]. Automotive manufacturers are increasingly investing in the refinement of electric vehicles as they are becoming an increasingly popular response to the global need for reduced transportation emissions. Therefore, there is a desire to extract the most fuel economy from a vehicle as possible. Some areas that manufacturers spend much effort on include minimizing the vehicle’s mass, body drag coefficient, and drag within the powertrain. When these values are defined or unchangeable, interest is driven to …

Nonmetallic Jet Impingement Thermal Management For Power Electronics Via Additive Manufacturing, Reece Whitt

Graduate Theses and Dissertations

The increase in energy demanded by transportation and energy sectors has necessitated highly efficient thermal management for reliable power electronics operations. Conventional cooling techniques are limited by their inability to target switching location hot spot temperatures, leading to non-uniform thermal gradients. These devices, such as cold plates and heat sinks, also utilize heavy metallic structures that can accentuate electromagnetic interferences generated by high voltage switching processes. This work proposes a non-metallic jet impingement cooler for more customized thermal management, while simultaneously reducing the harmful effects of electromagnetic interferences. Additive manufacturing is utilized to enable jet impingement zones to target individual …

Hobby Grade Lithium-Ion Batteries For Spacecraft Applications: Establishing An Automated Electrical Characteristics Testing Procedure For Flight Acceptance Of Non-Space-Grade Small Secondary Batteries, Braidon Hughes

Graduate Theses and Dissertations

Li-ion batteries are widely used due to the large amount of rechargeable energy they pack into a small, light package. This higher energy density makes Li-ion batteries ideal for small satellite applications, specifically CubeSats. CubeSats have grown in popularity in higher level education due to the National Aeronautics and Space Administration’s implementation of the Cube Satellite Launch Initiative, making it easier and cheaper to conduct small, low orbit missions. Because these CubeSats are occupying the same space as a crewed spacecraft, it is imperative that they are safe. There are numerous reports of Li-ion batteries creating fires that result in …

Gasification Based Waste Tire Integrated Energy Conversion Systems, Karah Powell

Honors Theses

The objective of this study was to evaluate the operating parameters impacts on the performance of a gasification-based waste tire integrated energy conversion system. In this system, the waste tires are put into a downdraft gasifier that is providing fuel for a solid oxide fuel cell (SOFC). The system is evaluated by the syngas production, power generation, and overall efficiency under various operating conditions. A hybrid 1-D model was adopted to perform a parametric study of the tire gasification and calculations were done to estimate the integrated system power generation and overall efficiency using MATLAB. Three parameters were studied: the …

Development And Application Of A Digital Twin For Chiller Plant Performance Assessment, Mihir Kale

All Theses

As the complexity of industrial equipment continues to increase, the management of the individual machines and integrated operations becomes difficult without computer tools. The availability of streaming data from manufacturing floors, plant operations, and deployed fleets can be overwhelming to analyze, although it provides opportunities to improve performance. The use of dedicated monitoring systems in the plant and field to troubleshoot machinery can be integrated within a product lifecycle management (PLM) architecture to offer greater features. PLM offers virtual processes and software tools for the design, analysis, monitoring, and support of engineering systems and products. Within this paradigm, a digital …

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 …

Atomistic Investigation Of Phase Stability And Sodium Ion Conduction In Sulfide Electrolytes., Sabina Zakhidovna Chertmanova

Electronic Theses and Dissertations

In this thesis, we employ a combination of density functional theory (DFT) calculations, and ab initio molecular dynamics (AIMD) simulations to identify the effect of chemical doping on (a) thermodynamic phase stability, and (b) Na-ion conduction in Na₃SbS₄ (NSS) solid-state electrolytes. We found that (a) Se doped electrolytes, namely, Na₃SbS_exS_4-x undergo a tetragonal-to-cubic structural phase transition at x > 3 (Se-rich), and (b) the size, valence, and electronegativity of chemical dopants that substitute Na in Na₃SbS₄ have a cumulative profound impact on Na-ion conductivity. Specifically, substituting Na with higher valence …

Design Of A 300cm2 Pemfc Stack With Force And Cfd Simulation To Optimize Flow Channels, Gasket Design, And Clamping Forces., Robert M. Ench

Electronic Theses and Dissertations

Proton exchange membrane fuel cells are important to the future of green energy as hydrogen can be made with green technologies and store energy for later use. Fuel cells can efficiently convert the hydrogen to electricity as needed. This study uses Solidworks simulation to make design improvements to the fuel cell before the prototype build stage of testing; this saves money and time by reducing the prototype builds needed.

In this study, a multi-channel serpentine design with two outlets versus a single outlet is evaluated using CFD to investigate pressure drop. Lower pressure drops are desirable as less energy input …

Solar-Powered Automated Transportation: Feasibility And Visualization, Burford J. Furman, Laxmi Ramasubramanian, Shannon Mcdonald, Ron Swenson, Jack Fogelquist, Yu Chiao, Alex Pape, Mario Cruz

Mineta Transportation Institute

A solar-powered automated transportation network (ATN) connecting the North and South campuses of San José State University with three passenger stations was designed, visualized, and analyzed in terms of its energy usage, carbon offset, and cost. The study’s methodology included the use of tools and software such as ArcGIS, SketchUp, Infraworks, Sketchup, Rhinoceros, and Autodesk 3DS Max. ATN vehicle energy usage was estimated using data from the university’s Park & Ride shuttle bus operation and by modeling with SUMOPy, the advanced simulation suite for the micro-traffic simulator SUMO. The energy study showed that an extensive solar photovoltaic (PV) canopy over …