Mechanical Engineering Commons^™

A Personal Tribute To Professor Ashok Midha, Larry L. Howell

Faculty Publications

When I received the news that Professor Ashok Midha had passed away, I was grieved by the unexpected news. But I also felt another emotion: gratitude for having known him. I am grateful for him, for the opportunity I had to learn from him, and for the influence he has had on my life and career. I wanted to honor his memory in some way. This document is in response to that desire.

Some of my thoughts at his passing are summarized in the first chapter and the conclusion. The other writing is taken from a draft of my personal …

Investigation Of Small-Scale Aerospike Nozzles For Cold Thrust Applications, Mohamed Hassan Almansoor

Thesis/ Dissertation Defenses

The aerospike engine appears to be a vision for engineers who are constantly seeking to better rockets in a world where one percent improvement is considered a massive growth. Aerospike nozzles are a very promising option and a near-term alternative of the conventional de Laval nozzles in the world of propulsion systems. Up to date there have been a few aerospikes that have advanced to this point at time. However, none have been used or utilized on a rocket nor any application to date. The aerospike nozzle capabilities are relatively more advanced than the conventional de Laval nozzle due to …

Residential Indoor Air Quality Study – Assessment And Mitigation, Giovanni Cerrato

Mechanical Engineering Theses

An increased awareness in residential indoor air quality (IAQ) has led to an increase in technologies that assist in improving IAQ. Two such technologies include Electro-static (ES) air cleaners and Photocatalytic Oxidizing (PCO) air cleaners. ES air cleaners remove particulate matter from indoor air, but are known to emit ozone, a contaminant, as a by-product. PCO air cleaners abate gaseous pollutants (i.e., Volatile Organic Compounds, VOCs); however, a lack of testing standards creates confusion about their effectiveness in improving IAQ in a real residential home. On the other hand, environmental variables such as temperature and humidity were found to affect …

Inverted Pendulum With Swing-Up And Center-Stabilization System Design, Caleb Osmond

Honors Program: Senior Projects (Public)

The inverted pendulum is a classic problem for testing control techniques. This paper details the implementation of multiple PID control schemes and the overall design of an inverted pendulum capable of swing-up and center stabilization.

Clean Energy & Sustainable Environment By Carbon Dioxide Mitigation Strategies, Md Fahim Shahriar

Mechanical Engineering Theses

Dissolution trapping is one of the most dominant mechanisms for secure storage of CO₂ injected in porous subsurface formations saturated with brine. This study uses a 2D visual Hele-Shaw cell to investigate and visualize the impact of CO₂ injection locations, reservoir dipping angle, permeability heterogeneity, and brine with different initial ionic concentrations on the density-driven convection during CO₂ dissolution (Chapter 2). Also, the role of complex heterogeneity, i.e., irregular permeability distribution in CO₂ dissolution, is investigated using a novel experimental approach to create medium permeability heterogeneity in Hele-Shaw cells (Chapter 3). We observed that the presence …

Mechanical Characterization Of Functionally Graded M300 Maraging Steel Cellular Structures, Bradley Jay Sampson

Theses and Dissertations

Traditional methods for increasing the energy absorption of a structure involve using a stronger material or increasing the volume of the structure, resulting in a higher cost or additional weight. Additive manufacturing (AM) can be used to maximize the energy absorption of materials with the ability to create complex geometries such as cellular structures. Previous work has shown that the energy absorption of additively manufactured parts can be improved through functionally graded cellular structures; however, this strategy has not been applied to ultra-high strength steel materials. This work characterizes the effect of multiple functional-grading strategies (e.g. uniform, rod-graded, size-graded) on …

A Review On Ship Recycling Industry In Bangladesh From Global Perspective, Ahammad Abdullah, Zobair Ibn Awal, M Ziauddin Alamgir, Md. Jobayer Mia, Farihatul Mim, Utpal K. Dhar

Journal of Ocean and Coastal Economics

At present, the global center of the ship breaking and recycling industry is in South Asia, specifically Bangladesh, India, and Pakistan. These three countries account for 70–80 percent of the international recycling market for ocean-going vessels, with China and Turkey covering most of the remaining market. Only about 5 percent of global volume is scrapped outside these five countries. Bangladesh has environmentally beneficial coastal region and affordable labor that make the shipbreaking and recycling business as a potential sector for the country. In addition, ship recycling and its related businesses are helping to solve our nation’s unemployment issues at all …

Cobalt Chromium In Biomedical Applications And The Development Of A Pspp Map, Nouralhouda Jamal

BCoE Publications

During the world wars, Cobalt-Chromium (Co-Cr) alloys gained prominence for their use in aircraft engine components, where they exhibited high temperature strength and durability. They are used in a wide range of industries due to their unique set of qualities, particularly strength, corrosion resistance, and biocompatibility. They have emerged as versatile materials with a broad spectrum of applications, from aerospace and automotive components to biomedical implants.

This paper presents a thorough analysis of its composition, processing techniques, microstructure, mechanical properties, and performance characteristics. The primary goal of this project is to develop a PSPP (Process, structure, properties, and performance) map …

Protecting Zn Anodes By Atomic Layer Deposition Of Zro2 To Extend The Lifetime Of Aqueous Zn-Ion Batteries, Shichen Sun, Yeting Wen, Aiden Billings, Roya Rajabi, Boyu Wang, Kangkang Zhang, Kevin Huang

Faculty Publications

Aqueous rechargeable Zn-ion batteries (ARZIBs) are a newly emerged class of electrochemical cells suited for large-scale stationary energy storage applications due to their unique advantages in safety, cost, and supply chain. To advance ARZIB technology toward commercialization, the corrosion problem of Zn anodes in aqueous electrolytes must be adequately addressed. Here we report our efforts to tackle this issue by using atomic layer deposition (ALD) to coat the Zn anode surface with a protective nanoscale ZrO₂ thin film, collectively denoted as ALD-ZrO₂@Zn in this study. We show the pertinent properties of ALD-ZrO₂@Zn in aqueous Zn-salt …

Comparison Of Methods For Estimating Instantaneous Turn Radius Of Ackermann Steering Vehicles, Kenneth Gennaro Stutts

Doctoral Dissertations and Master's Theses

The instantaneous turn radius of an Ackermann steering vehicle is the distance to a point in space about which the vehicle will travel in an arc during a turn. There are at least six ways to estimate instantaneous turn radius and each method uses different inputs and has distinct advantages and disadvantages. In this thesis, six different methods will be used to estimate the instantaneous turn radius of a vehicle traveling on a closed circuit. This testing will clarify similarities and differences between the methods. This thesis clarifies which method will be the most appropriate for a given set of …

Measuring Gas Discharge In Contact Electrification, Hongcheng Tao, James Gibert

Purdue University Libraries Open Access Publishing Fund

Contact electrification in a gas medium is usually followed by partial surface charge dissipation caused by dielectric breakdown of the gas triggered during separation of the surfaces. It is widely assumed that such discharge obeys the classical Paschen’s law, which describes the general dependence of the breakdown voltage on the product of gas pressure and gap distance. However, quantification of this relationship in contact electrification involving insulators is impeded by challenges in nondestructive in situ measurement of the gap voltage. The present work implements an electrode-free strategy for capturing discrete discharge events by monitoring the gap voltage via Coulomb force, …

Exploring Regular And Turbulent Flow States In Active Nematic Channel Flow Via Exact Coherent Structures And Their Invariant Manifolds, Caleb G. Wagner, Rumayel H. Pallock, Jae Sung Park, Michael M. Norton, Piyush Grover

Department of Mechanical and Materials Engineering: Faculty Publications

This work is a unified study of stable and unstable steady states of 2D active nematic channel flow using the framework of Exact Coherent Structures (ECSs). ECSs are stationary, periodic, quasiperiodic, or traveling wave solutions of the governing equations that, together with their invariant manifolds, organize the dynamics of nonlinear continuum systems. We extend our earlier work on ECSs in the preturbulent regime by performing a comprehensive study of stable and unstable ECSs for a wide range of activity values spanning the preturbulent and turbulent regimes. In the weakly turbulent regime, we compute more than 200 unstable ECSs that coexist …

Effect Of A Geothermal Heat Pump System On Cooling Residential Buildings In A Hot, Dry Climate, Rania Rushdy Moussa, Ayman H. Mahmoud

Architectural Engineering

ABSTRACT In the last century, electricity demand has doubled due to urban expansion, which has contributed to the formation of more urban heat islands (UHI) and the appearance of environmental hazards such as the global climate change phenomenon. Since residential buildings are considered the main electricity consumer sector in Egypt, they consume up to 42% of total energy consumption, which contributes to increasing temperatures and constitutes UHI in cities. In this context, the research aims to examine the effectiveness of using the closed vertical loop geothermal system (GSHPCV) for cooling residential buildings in a hot, dry climate, such as Cairo, …

An Image Processing Technique For Studying The Flame Structure Using Single Shots Of Oh-Plif Diagnostics, Hazem M. Al-Bulqini, El-Shafie B. Zeidan, Farouk M. Okasha, Mohy S. Mansour

Mansoura Engineering Journal

Laser diagnostic techniques have played a crucial role in enhancing our understanding of combustion processes. Among these techniques, Planar Laser-Induced Fluorescence (PLIF) utilizing OH radicals has proven to be a powerful tool for investigating reaction zones, flame curvature, and flame surface density in diverse flame modes including premixed, non-premixed, and partially premixed flames. However, to fully harness the potential of experimental measurements and laser diagnostics in studying combustion processes, a comprehensive grasp of image processing techniques and tools is essential for effectively analyzing captured images and extracting valuable information. In this study, we present a detailed algorithm that facilitates the …

Code To Combustion: Cnc Rotor Replication Using Cam, Luis Luna

Publications and Research

In the current landscape, computer-aided design (CAD) and computer numerical control (CNC) technologies have greatly enhanced manufacturing processes, allowing rapid and high-precision production. This project will focus on recreating a Wankel engine rotor, using SolidWorks for design and Mastercam for Computer-Aided Manufacturing (CAM) simulations. The process begins with SolidWorks, which is used for a template of a high-precision rotor model. Mastercam is then utilized for the CAM programming, allowing for the creation of intricate tool paths and tool usage simulations. This approach is vital for complex objects like the Wankel engine rotor, which demands high precision. The primary objective of …

Experimental And Modelling Of Lightning Damage To Carbon Fibre-Reinforced Composites Under Swept Stroke, Chengzhao Kuang, Kunkun Fu, Juhyeong Lee, Huixin Zhu, Qizhen Shi, Xiaoyu Cui

Mechanical and Aerospace Engineering Faculty Publications

Lightning swept stroke creates multiple lightning attachments along an aircraft in flight. This introduces distinct structural damage compared to that from a single-point lightning current injection test in laboratory. This study presents both experimental and numerical studies on lightning damage in carbon fibre-reinforced polymer (CFRP) composites under swept stroke. Coupled electrical–thermal finite element (FE) models were proposed to predict lightning damage to CFRP composites under single-point current injection and swept stroke, respectively. A lightning swept stroke testing method was proposed by embedding a copper wire inside the composites to simulate multiple lightning attachments on the composites. The FE-predicted damage from …

4d Printing Of Pla And Pla-Based Composites For Load-Bearing Applications, Phaniteja Nagaraju

ETD Archive

This research investigates the deformation recovery of 3D-printed Polylactic Acid (PLA) shape memory polymers (SMPs). The study delves into the influence of Fused Deposition Modelling (FDM) parameters, such as nozzle temperature, layer thickness, and printing speed, on the thermomechanical behavior of PLA SMP honeycomb structures. The research identifies optimal printing conditions using the Taguchi approach and explores the cyclic shape memory recovery behavior of the optimized PLA SMP under compression loads.

Additionally, the research includes a chapter on the extrusion and printing of uniform-diameter polylactic acid carbon fiber (CFR-PLA) composite filaments. The synthesis of CFR-PLA involves planetary ball milling for …

Capabilities Of Sintered Silver As A High Temperature Packaging Material, Bakhtiyar Mohammad Nafis

Graduate Theses and Dissertations

With electrification progressing across many sectors including industry, automotive and aerospace, the power density requirements are changing. The increased power density results in higher and higher ambient temperatures that electronics are exposed to. The response has been to move towards wide bandgap (WBG) semiconductor devices that can withstand much greater temperatures and can operate at much higher voltages than silicon. Additionally, these WBG devices deliver low drain-source on resistance (RDS_on) capabilities, enabling high current power modules that increase power density even further. This also requires the packaging to evolve in order to withstand the new requirements. As a result, researchers …

Development Of A Prototype Satellite-Tracking Telescope For Ground-Based Spectroscopy, Charles Smith

Graduate Theses and Dissertations

Spectroscopy is the practice of determining the chemical composition of a gas through analyzing the light that is filtered by the gas. Spectroscopy is commonly used by astronomers to deduce the atmospheric composition of planets. This process is done by initially measuring the spectrum of light from the star that the planet orbits, and then measuring it again once the planet is in between the observer and the star. The spectrum light that is filtered out is dependent on the chemical composition of the gas, and so this information can be used to determine the chemical composition of the atmosphere …

Silver Sintering Reliability And Its Enhancement For Use In High-Density Power Modules, Alicia Medina Garcia

Graduate Theses and Dissertations

This master's thesis is dedicated to enhancing the reliability of silver sinter die attachments, a pivotal component within the dynamic realm of power electronics. The study is meticulously organized into four distinct chapters, each contributing to a comprehensive understanding of silver sinter die attachment reliability and its implications for contemporary electronic packaging. In Chapter 1, an introduction is provided to the significance of silver sinter die attachment in the context of power electronics, underlining the imperatives associated with miniaturization, weight reduction, and heightened efficiency. The compelling need to investigate die attachment properties, particularly in high-temperature and high-power-density environments, is emphasized. …

Design And Demonstration Of An Inertial-Stabilized Single-Axis Headlamp For Mobile Systems, Thomas Avery Allsup

Mechanical and Aerospace Engineering Dissertations - Archive

The introduction of adaptive headlamps has added left and right movement of the headlamps to enhance the vision of the driver during a turn at night. Adaptive headlamps also allow up and down motion of headlamps in either two discrete positions with low and high beams based on vehicle speed and oncoming traffic lights or using the vehicle suspension measurement to adjust headlamp beam angles in any angle between low and high. Using the vehicle suspension ignores the roadway influence on where the headlamps should be positioned to illuminate the roadway for the driver. This dissertation develops governing equations and …

On The Development Of A Sensing System Methodology To Evaluate The Viscoelastic Properties Of Soft Tissues As A Means Of Disease Prognosis, Shashank S. Kumat

Mechanical and Aerospace Engineering Dissertations - Archive

Identification of tissue viscoelastic properties could provide valuable information for assessing its healthiness or disease state. Current technologies present challenges to access and perform localized tissue assessment in confined spaces in the human body through contact indentation/palpation. As such, there is a need for a diagnostic system capable of measuring tissue relaxation response at the local site by accessing the tissue through a natural orifice. This dissertation presents a strain gauge-based uniaxial micro-force sensor, part of the aforementioned system, capable of measuring tissue response data in confined human space environments. A sensing system design methodology is developed and presented. The …

Optimizing Energy Efficiency And Performance In High-Performance Computing Through Advanced Direct-To-Chip Liquid Cooling And Labview-Based Monitoring And Analysis, Chandraprakash Ashok Hinge

Mechanical and Aerospace Engineering Dissertations - Archive

This research endeavors to significantly enhance energy efficiency and performance in the realm of high-performance computing (HPC). This goal is pursued through a synergistic approach that leverages advanced direct-to-chip liquid cooling systems and integrates LabVIEW for real-time monitoring and analysis within data centers. The primary aims of this study are manifold. First, it seeks to evaluate the effectiveness of different single-phase liquid coolants when employed in direct-to-chip cold plate cooling for HPC systems. Additionally, the research focuses on characterizing row manifolds, crucial elements in the design of efficient data centers. The study also endeavors to devise a strategic control mechanism …

Multiple Dipole Source Position And Orientation Estimation Using Non-Invasive Eeg-Like Signals, Saina Namazifard

Mechanical and Aerospace Engineering Dissertations - Archive

The human brain comprises of neurons that connect with each other via electrical signals. One can record and measure these activities using an electroencephalogram (EEG). An essential use of the EEG is in locating the generating source of these signals, usually approximated by dipoles. This is important because, in some particular circumstances, neurons may not function optimally and could make the equivalent dipole generate abnormal signals. This could be a result of seizures or other brain disorders. In order to isolate such disorders, the challenge is to find a non-invasive way to locate the anomalous source. This research aims to …

Thermo-Mechanical Analysis Of Heterogenous Integrated Packages And Immersion Cooling Of Data Center Servers, Krishna Bhavana Sivaraju

Mechanical and Aerospace Engineering Dissertations - Archive

III-V materials such as Gallium Arsenide (GaAs) and Indium Phosphide (InP) are used as substrates for opto-electronic devices like vertical cavity surface emitting lasers (VCSEL), edge emitting lasers and light emitting diodes. System in Package integration of the III-V materials to silicon requires a reliable bonding technique. Though there are several bonding techniques like direct wafer bonding like hetero-epitaxially grown islands on a silicon wafer bonding enable the bonding, flip-chip bonding is used in this study owing to its superior electrical connectivity, mechanical reliability, heat conduction capability and ease of fabrication due to self-alignment. Finite element models of four different …

An Apparatus To Quantify Lengthwise Flexural Rigidity Profiles Of Endovascular Devices, Charles B. Suskin

McKelvey School of Engineering Graduate Student Theses & Dissertations

Endovascular procedures require access to distal anatomical sites through the vasculature using catheters and guidewires. Quantitative frameworks for device behavior during procedures hold the potential to drive device design through greater understanding of the mechanical behavior of endovascular devices, and offer the potential to personalize care based on a patient's particular vascular anatomy. However, data that would facilitate this technology are lacking, partly due to undisclosed material properties from manufacturers and partly due to the intricate variations along the length of each device due to material changes and the intersections between them. We developed a three-point bend test methodology on …

Enhanced Fabrication Of Microdroplet Generator Nozzle Arrays: Optimizing Koh Etching For Microfluidic Applications, Hongyu Bai

McKelvey School of Engineering Graduate Student Theses & Dissertations

Ultrasonic microdroplet generators are useful devices with broad applications ranging from aerosolized drug delivery to three-dimensional (3D) printing-based additive manufacturing. One such technology comprises a microfabricated array of nozzles with droplet production driven by a piezoelectric transducer. The present study focuses on refining a critical fabrication step, anisotropic wet etching of pyramidal nozzles using a basic potassium hydroxide (KOH) solution. Given the integral role of nozzle geometry in device operation, high-precision techniques including Reactive Ion Etching (RIE), Deep Reactive Ion Etching (DRIE), and KOH wet etching were employed. A tapering geometry is preferred for acoustic wave focusing and efficient droplet …

Model Of Surface Waves On A Viscoelastic Material In A Cylindrical Container With Edge Constraints, Phillip Wilson

All Theses

A theoretical model is developed for the resonant frequencies and mode shapes of pinned edge surface waves on a viscoelastic fluid contained in a finite depth cylindrical container. A boundary integral approach is used to map the governing equations to the domain boundary. The surface waves obey an eigenvalue operator equation that depends on four dimensionless parameters: the cylinder aspect ratio, the Bond number, the Ohnesorge number, and the elastocapillary number. A solution is constructed using a Rayleigh-Ritz variational procedure over a constrained function space, which is able to effectively incorporate the pinned edge boundary condition. Mode shapes are defined …

Thermal Atomization On Superhydrophobic Surfaces Of Varying Temperature Jump Length, Eric D. Lee, Daniel Maynes, Julie Crockett, Brian D. Iverson

Faculty Publications

This paper presents an experimental study of drop impingement and thermal atomization on hydrophobic and superhydrophobic (SH) surfaces. Superhydrophobic surfaces having both microscale and nanoscale geometry are considered. Microscale SH surfaces are coated with a hydrophobic coating and exhibit micropillars and cavities which are classified using the surface solid fraction and center to center pitch. The solid fraction and pitch values explored in this study range from 0.05-1.0 and 8-60 μm respectively. Nanoscale textured surfaces are created by applying a blanket layer of carbon nanotubes. Both types of surfaces are further classified by a temperature jump length (λ …

Cnc Retrofits, Fabian Samano, Murat Askin, Daniel Lonczak, Zane Campise

Mechanical Engineering

The Boxford CNC Lathe is a machine used for educational purposes. The goal of the CNC Retrofits project is to improve the Boxford MT2’s performance and functionality to enable Mr. Lonczak to manufacture customized ballpoint pens. Within this Final Design Review (FDR) document, we present design updates since the CDR and implementation/assembly techniques. This work culminates in a solution to Mr. Lonczak’s needs which is analyzed in three subsystems: main control, spindle position tracking, and user interface. Within this report, we show the results of each subsystem’s verification process. These results prove that the design concept was met by describing …