Engineering Commons^™

Influence Of Heat Treatment And Shielding Gas Environment On The Very High Cycle Fatigue Behavior Of 17-4 Precipitation Hardened Stainless Steel, Jade Welsh

UNF Graduate Theses and Dissertations

Additive manufacturing (AM) for stainless steel components has proved useful in a variety of industries ranging from aerospace to biomedical engineering. Many of these components are subject to very high cycle fatigue (VHCF) loading and must have tailored mechanical properties to ensure failures do not occur before a service life is reached. Testing the fatigue strength AM materials exposed to VHCF loading is paramount to compare with the expected life cycles of their wrought counterparts. In this thesis, AM 17-4 precipitation hardened (PH) stainless steel (SS) were fabricated using laser powder bed fusion (L-PBF) technique, while the wrought 17-4 PH …

Design And Implementation Of Portable Power And Desalination Units Powered By Renewable Energy, Mo'ath A. Massad

Mechanical Engineering Theses

Freshwater scarcity is a critical global issue, especially in remote areas or areas impacted by natural disasters. Water desalination is one of the most effective methods to provide fresh water where it is needed. However, large-scale desalination plants cannot provide fresh water in the case of a natural disaster far from the plant's location. To address this, portable desalination units powered by renewable energy sources can be developed to supply potable water and power as a by-product for emergency situations. This work explored the application of different desalination methods, including reverse osmosis (RO) and electrodialysis (ED), in conjunction with renewable …

Warm Unit Stand Assembly And Testing For Proton Improvement Project Ii, Christopher Allen English

Graduate Research Theses & Dissertations

The Proton Improvement Project II (PIP II), situated at Fermilab, signifies a critical advancement in the realm of high-energy physics. PIP II, a linear accelerator renovation endeavor, aspires to double the output of the existing proton beam, reinforcing Fermilab’ s position as a vanguard in this field. The proton beam's creation involves a series of high-frequency cryomodules, necessitating environmental temperature arrays of magnets and vacuum pumps henceforth described as ‘Warm Units.’ The Warm Units include design features of : 1. insertion between the cryomodules, 2. multi-stage adjustments in six degrees of freedom to ensure precise beam alignment; 3. Natural frequency …

Dynamics Of A 3-D Inlet/Isolator Measured With Fast Pressure-Sensitive Paint, Andrew N. Bustard, Mark E. Noftz, Mitsugu Hasegawa, Hirotaka Sakaue, Joseph S. Jewell, Nicholas J. Bisek, Thomas J. Juliano

Publications

Fast pressure-sensitive paint (PSP) was applied to an inlet/isolator designed using the Osculating Internal Waverider Inlet with Parallel Streamlines (OIWPS) method. The dorsal isolator surface pressure was measured using anodized-aluminum PSP through transparent cast acrylic that makes up the ventral portion of the isolator. Temperature-sensitive paint was utilized to correct for the PSP’s temperature sensitivity. The model was tested under Mach 5.7 flow at Re = 8.5 ×106 /m and 10.2 ×106 /m in the AFOSR–Notre Dame Large Mach-6 Quiet Tunnel (ANDLM6QT) under conventional noise conditions. Flow phenomena, such as shocks originating in the inlet and flow separation at the …

Control Of Flow Instabilities With Acoustic Metamaterials, Jensen E. Mctighe

Open Access Master's Theses

Acoustic metamaterials (AMs) have been proposed for uses in flow control, as they offer a passive control method and can be engineered independently, without needing complex fluid structure interactions simulations. For example, AMs embedded into flat plate surfaces have been demonstrated to delay (or speed up) the onset of laminar-to-turbulent boundary layer transition by attenuating (or strengthening) Tollmein-Schlicting waves through numerical simulation. However, as of present, no experimental research has been conducted to study or demonstrate the behaviors of AMs designed to interact with flow structures. An experiment was performed in which an AM was embedded into a flat plate …

Hybrid Triboelectric-Piezoelectric Nanogenerator For Long-Term Load Monitoring In Total Knee Replacements, Mahmood Chahari, Emre Salman, Ryan Willing, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

A self-powered and durable pressure sensor for large-scale pressure detection on the knee implant would be highly advantageous for designing long- lasting and reliable knee implants as well as obtaining information about knee function after the operation. The purpose of this study is to develop a robust energy harvester that can convert wide ranges of pressure to electricity to power a load sensor inside the knee implant. To efficiently convert loads to electricity, we design a cuboid-array-structured tribo-pizoelectric nanogenerator (TPENG) in vertical contact mode inside a knee implant package. The proposed TPENG is fabricated with aluminum and cuboid-patterned silicone rubber …

Towards Self-Powered Load Imbalance Detection For Instrumented Knee Implants Using Quadrant Triboelectric Energy Harvesters, Mahmood Chahari, Hoesin Haghshenas, Emre Salman, Milutin Stanacevic, Ryan Willing, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

In this study, we proposed a triboelectric nanogenerator (TENG) as a pressure sensor to measure the load imbalance on the tibial tray. To detect the load imbalance, we proposed a segmented quadrant design. The TENG pressure sensors with various micro-patterns, including pyramid, cylindrical, and bar patterns, are utilized to measure the axial forces with different sensitivity in different quadrants of the tibial tray. The functionality of the instrumented implant is examined through experimental testing on the package, evaluating its sensing capabilities and power harvesting. The relationship between each quadrant output and the axial force is determined, which enables characterizing the …

Thermomechanical Process Simulation And Quantification Of Nanoscale Precipitation Influencing Ductility And Strength During Alloy Processing, Alyssa Stubbers

Theses and Dissertations--Chemical and Materials Engineering

Experimental process simulation and quantification of microstructure development during processing are challenging due to limitations with machinery temperature capability, inadequate resolution and sampling volume of currently available characterization techniques, and difficulty characterizing material microstructures as close to processing-relevant conditions as possible. This dissertation addresses how process simulation can be performed using Gleeble thermomechanical technologies and how microstructure development during these processing simulations can be quantified both in-situ and ex-situ.

The first portion of this dissertation demonstrates how Gleeble technologies can be applied to simulate complex material processing conditions in order to produce process-property profiles that can be used to inform …

Simultaneous Evaluation Of Tibiofemoral And Patellofemoral Mechanics In Total Knee Arthroplasty: A Combined Experimental And Computational Approach, Yashar A. Behnam, Ahilan Anantha Krishnan, Hayden Wilson, Chadd W. Clary

Center for Orthopaedic Biomechanics: Faculty Scholarship

Contemporary total knee arthroplasty (TKA) has not fully restored natural patellofemoral (P-F) mechanics across the patient population. Previous experimental simulations have been limited in their ability to create dynamic, unconstrained, muscle-driven P-F articulation while simultaneously controlling tibiofemoral (T-F) contact mechanics. The purpose of this study was to develop a novel experimental simulation and validate a corresponding finite element model to evaluate T-F and P-F mechanics. A commercially available wear simulator was retrofitted with custom fixturing to evaluate whole-knee TKA mechanics with varying patella heights during a simulated deep knee bend. A corresponding dynamic finite element model was developed to validate …

Comprehensive Review And Development Of A High-Pressure Hydraulic Impedance Tube For Vibroacoustic Attenuator Characterization, Matthew D. Beals

Dissertations, Master's Theses and Master's Reports

This research establishes a versatile test bench for characterizing hydraulic vibroacoustic attenuators. The primary evaluation metric is the transfer matrix, determined experimentally, with an emphasis on key properties such as transmission loss. To ensure accuracy and broad applicability, the methodology is based on industry-standard techniques for determining the transfer matrix. A comprehensive literature review consolidates existing approaches for hydraulic attenuator characterization. The test bench features a hydraulic impedance tube equipped with eight dynamic pressure transducer (DPT) taps strategically positioned before and after the sample interface. This setup accommodates arbitrary samples terminated with standard hydraulic fittings. Using ASTM E2611, the transfer …

Me-Em Enewsbrief, December 2023, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Insights Into The Heart Microstructure: A Case Study, Sarah Bulger

Honors Undergraduate Theses

This thesis focuses on better understanding the structures of the heart at the micro-scale. Cardiomyocytes and the branching of cardiomyocytes are of specific interest. A literature review was performed to extract key information on cardiomyocyte size, the branching type and frequency of cardiomyocytes, and cardiomyocytes' organization in general. The purpose of conducting the literature review was to find quantifiable data on the micro-structure of the heart. Three studies in particular provided data on the branching of cardiomyocytes. Two of these studies were conducted on rat hearts, while one other study was conducted on human hearts. The methods and terminology between …

Extrusion-Based Additive Manufacturing Of Magnetic Heat Exchange Structures For Caloric Applications, Vaibhav Sharma

Theses and Dissertations

Currently, the commercial building sector accounts for 18% of total U.S. end-use energy consumption, of which almost a third was from on-site combustion of fossil fuels for space and water heating. Magnetic heat pumping (MHP) technology is an energy-efficient, sustainable, environmentally-friendly alternative to conventional vapor-compression cooling technology. Several MHP designs today are predicted to be highly energy efficient, on condition that suitable working materials can be developed. This materials challenge has proven to be daunting due to issues associated with intricate synthesis/post-processing protocols and complications related to shaping the mostly brittle magnetocaloric alloys into thin-walled channeled regenerator structures to facilitate …

Energy Efficient Spintronic Devices For Non-Volatile Memory And Hardware Ai, Walid Al Misba

Theses and Dissertations

Nanomagnetic devices have emerged as a promising alternative to conventional complementary metal-oxide-semiconductor (CMOS) devices due to their low energy dissipation and inherent non-volatility. However, the widespread adoption of these devices requires high-density, high-speed, reliable, scalable, and energy-efficient technologies. This thesis investigates the use of nanomagnetic memory devices as both conventional Boolean memory and multistate memory for hardware AI applications.

Magnetic tunnel junctions (MTJs) are nanomagnetic memory devices that can be switched reliably and energy-efficiently using stress-mediated switching. However, realistic material inhomogeneity and scalability pose challenges for stress-mediated switching of MTJs scaled to lateral dimensions below 50 nm. We demonstrate that …

Fluid Flow And Thermal Performance Investigation Of Twisted Elliptical Tubes For Use In High Prandtl Number Systems, Connor F. Donlan

Theses and Dissertations

The development of clean energy systems is paramount to reducing mankind's climate impact. These clean energy systems include solar, wind, and nuclear power where nuclear power shows a reduced lifetime carbon dioxide footprint per kilowatt hour compared to other sources [102]. Advanced nuclear reactors, fusion energy systems, and concentrated solar power designers are looking at using molten salt heat transfer fluids and improved heat exchanger design to increase power production and efficiency of clean energy systems. The improving heat transfer within the main heat transfer components within advanced nuclear reactors will enable increased efficiencies and power production.

Heat transfer improvements …

Towards The Automation Of Post-Processing Of Additive Manufacturing Using Collaborative Robots, Logan Schorr

Theses and Dissertations

Despite the incredible potential that collaborative robots have, they are underutilized in several industries that could benefit greatly. These specialized fields, such as additive manufacturing, face challenges that can be solved with the use of robotics, including advanced computer vision, end-effector tooling, and process refinement. My research aims to utilize collaborative robots in an effort to solve the above stated problems, for the specific fields of additive manufacturing. Specifically within this field is the automation of post-processing; this is normally completely manual, as the tools for automation are not sufficiently developed to handle the flexibility required for additive manufacturing. This …

Design And Analysis Of Coupler Installation Tooling With Computer Vision For Fermilab’S Single Spoke Resonator 2 Srf Cavity, Caleb T. Denton

Graduate Research Theses & Dissertations

Fermi National Laboratory (Fermilab) and the European Council for Nuclear Research (CERN), forerunners in the exploration of the subatomic world, are both in the process of improving their particle accelerators with the Proton Improvement Plan II at Fermilab and the High-Luminosity Large Hadron Collider Accelerator Upgrade Plan (HL-LHC AUP) at CERN. Both particle accelerators have cavities that serve to either accelerate the particle beam or guide it into an optimal position and have the need for radio frequency (RF) power couplers to generate the field that controls the particle beams. When installing the coupler onto the cavity, a reliable vacuum …

Modeling And Performance Evaluation Of Traditional And Ai-Based Mppt Techniques For Photovoltaic Systems., Md Badruddaza

Graduate Research Theses & Dissertations

The efficiency levels to convert from sunlight to electricity are in the range up to 22% commercially, based on the technology used. Due to comparatively low efficiency of photovoltaic systems, it is imperative to extract maximum power from the PV module array. Thus, in solar PV system, tracking the module’s MPP (maximum power point) is crucial and at the same time challenging as well due to varying climatic conditions. This research focuses on the modeling and performance evaluation of traditional Maximum Power Point Tracking (MPPT) techniques and AI-Based MPPT algorithms in photovoltaic systems. It addresses the issue of dynamic adjustment …

A One-Wheeled Robot For Exploring Rolling Disk Locomotion, David H. J. Schmidt

Graduate Research Theses & Dissertations

The work proposed in this thesis is motivated by observations of one-wheel vehicles called monocycles. Whereas the unicycle has the rider sitting on a seat above the wheel, the monocycle’s rider sits inside a large circular hoop that serves as the wheel. Due to the position of the rider inside the wheel, it lowers the overall center of mass of the vehicle below the center of the wheel. For this reason, the uncontrolled longitudinal (forward/backward, or drive axis) dynamics are stable. For modest speeds above a certain threshold, the lateral (side-to-side, or lean axis) dynamics of the monocycle are also …

Bidirectional In-Situ Analysis And Visualization Of Fluid Structure Interactions With Applications In Blood Flow, Nazariy Tishchenko

Graduate Research Theses & Dissertations

Interactive blood flow simulation has applications in the understanding of complex fluids,training medical professionals, diagnostics, and surgical procedure planning. Bidirectional in situ visualization and analysis are much needed to streamline the analysis of large-scale patient-specific blood flow simulations. The in situ component ensures the live visualization of the simulation results while the simulation is running, and the bidirectional component allows for real-time control and configuration of the simulation parameters (i.e., setting and retrieving the simulation parameters and data based on need). In this project, a highly accurate multiphysics simulation was instrumented to work with an existing bidirectional in situ framework. …

Feasibility Study Of Managing Peak Cooling Loads To Achieve Energy Cost Reduction In A Northern Climate Campus, Mark Rizkalla

Electronic Theses and Dissertations

South Dakota State University Facilities and Services Office is facing the challenge of paying high electricity bills every year, the potential of campus growth will add more burden on the energy needed to cover this demand, especially in summer months when high cooling loads are added to the electrical loads which lead to the peak loads that costs SDSU a large amount of money. The purpose of this research is to study the feasibility of managing the peak loads to reduce energy costs by applying a suitable system that fits SDSU campus nature. The methodology used is studying the capability …

Simulation Of Reacting Supersonic Flow In A Cavity Flameholder, Mohamed Benjelloun Touimi

Electronic Theses and Dissertations

Scramjet engines, or Supersonic Combustion Ramjets, are pivotal for achieving and maintaining hypersonic flight speeds. These engines leverage the high-speed airflow to compress and mix air and fuel for combustion. A significant challenge in Scramjet engine design is ensuring stable and efficient combustion within this high-speed environment. Cavity flameholders are crucial components that stabilize the combustion process by creating a subsonic region where the fuel-air mixture can ignite and sustain combustion. This research simulates this supersonic flow within the combustion chamber to accurately model and analyze the combustion dynamics. Various turbulence models, including RANS, and DES, are evaluated for their …

Computational Characterization Of Extracellular Electro-Osmotic Flow During Tissue Repair, Ashley Jorgensen-Blocker

Electronic Theses and Dissertations

Electrical stimulation (ES) therapy promotes the healing of chronic epidermal wounds and suppresses the degeneration of articular cartilage. Despite the success of ES therapy, the underlying mechanisms by which ES promotes tissue repair are largely unknown, preventing the standardization and optimization of treatments. One proposed mechanism involves electro-osmotic flow (EOF), electrically driven water flow generated within close proximity to the cell surface. EOF induces the transport of macromolecules and removes metabolic wastes and inflammatory molecules from these dense tissues through interstitial flow. This dissertation investigates the application of weak electric fields (EFs) to non-excitable cells and the generation of EOF …

Co-Firing Of Lpg And Diesel Fuels Through An Innovative Double Swirl Burner: Combustion Characteristics And Exhaust Emissions, Eslam O. Mater, Karim M. Soliman, A. Abdulnaim, Ahmed Abdelrazik Emara, Ahmed Salah Elsahy, Hany A. Moneib

Trends in advanced sciences and technology

The current stringent environmental regulations, the depletion of fossil fuels and the emergence of oil biofuels and synthetic gases had motivated combustion scientists to search for alternative technologies that meet efficient burning, flexible use of multiple fuels and conform to a clean environment. In that respect, several developments had emerged including, low swirl combustion for partially premixed mixtures, “Mild” combustion for diffusion flames. The present experimental study introduces a new concept that combines separate admissions of fuel and air with a central recirculation zone following the diffusion combustion mode, partial premixing within a premix chamber resulting in the creation of …

Air Jet Assisted Combustion Of Oil Diffusion Flames: Effects Of Injection Location And Excess Air Factor, Moustafa Ahmed Gamaleldin, Neama Youssef Ramadan, Ahmed Mohamed Abdulnaim, Ahmed Abdelnasser Adam, Ahmed Abdulrazik Emara, Hany Ahmed Moneib

Trends in advanced sciences and technology

This study investigates a novel methodology for a coaxial disc stabilized burner with a central jet oil spray. It introduces multiple air injection jets within the burner gun's exit section, promoting earlier fuel vaporization and rapid fuel-air mixture formation in the premixing zone. This directly contributes to improved overall combustion efficiency and reduced exhaust emissions. The focus lies on identifying the optimal location for the air injection jets (fixed load, constant jet momentum, and angle) within the exiting premixing zone of the burner gun. In-flame measurements are conducted inside a cylindrical combustor at different air injection locations and varying excess …

Dynamic Analysis And Experimental Verification Of Flexible Unbalance Rotor Supported By Two Identical Journal Bearings, Omar Ahmed, Hussein Sayed, T.A. El-Sayed

Trends in advanced sciences and technology

Abstract BACKGROUND: Analyzing the vibrations for rotor-bearing systems is a critical issue in the field of rotor dynamics. It is crucial to identify rotary machine vibrations, behaviors, and stability conditions. The main causes of vibration in rotating machinery are unbalanced masses, misalignment, mechanical looseness, shaft cracks, and other defects. METHODS: This paper investigates the experimental verification of a theoretical model, using a steel shaft with a disc set at the midpoint, supported by two symmetric fluid film bearings. The study examines the effect of unbalance on the dynamic behavior of the rotor and its vibration characteristics. The experimental investigation involved …

On The Use Of The Local Reflection Coefficient To Assess The Diffuse Field Sound Absorption Coefficient Of A Porous Material, Franck Sgard, Noureddine Atalla, Olivier Robin

Études primaires

The diffuse field sound absorption coefficient (SAC) of a sound absorber can be obtained from an average over the incidence angles of the oblique incidence plane wave SAC. The plane wave SAC can be derived from the plane wave complex-valued reflection coefficient defined as the ratio of the reflected sound pressure at a given point on the material surface to the incident sound pressure at the same point. In practice, the material is excited by a monopole, and the reflection coefficient becomes a local quantity which is a function of the source height and the radial distance from the source. …

On The Area-Averaged Effective Sound Absorption Coefficient Of Porous Materials Excited By A Monopole, Franck Sgard, Noureddine Atalla, Olivier Robin, Alain Berry

Études primaires

The area-averaged effective sound absorption coefficient (SAC) of a rigid-backed homogeneous porous material subjected to a monopole excitation is calculated as the absorbed-to-incident sound power ratio. Using Allard's model to describe the sound propagation above the porous material, an analytical model for this power-based SAC is proposed and proves to give a good approximation of the sound absorption performance under monopole excitation of sufficiently large areas of material. The impact of factors on the power-based SAC, such as monopole height, material radial dimension used to calculate the sound powers, and material properties is discussed. The power-based SAC frequency-dependent behavior is …

Measurement Of The Local Static Mechanical Pressure Of Earplugs, Luiz G.C. Melo, Ahmed S. Dalaq, Franck Sgard, Olivier Doutres, Laurianne Legroux, Eric Wagnac

Études primaires

Earplugs are used in various critical industrial sectors, such as construction, aviation, military and defense, transportation, and healthcare. However, they present inherent drawbacks, notably discomfort that can lead to inconsistent and incorrect use, thereby leaving a significant proportion of workers vulnerable to irreversible hearing damage, ranging from tinnitus to deafness. This discomfort is closely linked to a physical parameter known as static mechanical pressure (SMP), representing the pressure exerted by earplugs on the earcanal walls. Determining the SMP is crucial for developing earplugs that prioritize comfort. However, experimental studies in this area are scarce and there is no experimental set-up …

An Impedance Tube Technique For Estimating The Insertion Loss Of Earplugs, K. Carillo, O. Doutres, F. Sgard

Études primaires

This paper proposes a quick and straightforward technique for estimating the insertion loss (IL) of earplugs measured on an acoustical test fixture (ATF) using a commercial impedance tube. In this method, the earplug's acoustic properties (i.e., its transmission loss and the reflection coefficient of its medial surface) are determined from its transfer matrix measured using the three-microphones impedance tube method modified here for the current application. The IL is then estimated using a one-dimensional analytical model of open and occluded earcanals based on the wavefield decomposition theory. The method is evaluated numerically and experimentally from 50 Hz to 6.5 kHz. …