Mechanical Engineering Commons^™

Stochastic Simulation Of Construction Methods For Multi-Purpose Utility Tunnels, Shayan Jorjam, Mohammed Mawlana, Amin Hammad

College of Architecture and the Built Environment Faculty Papers

The traditional method of installing underground utilities (e.g., water, sewer, gas pipes, electrical cables) by burying them under roads has been used for decades. However, the repeated excavations related to this method cause problems, such as traffic congestion and business disruption, which can significantly increase financial and social costs. Multi-purpose Utility Tunnels (MUTs) are a good alternative for buried utilities. Although the initial cost of MUTs is higher than that of the traditional method, social cost savings make them more feasible, especially in dense urban areas. Different factors, such as the specifications of utilities, the location of the MUTs, and …

Polycyclic Aromatic Hydrocarbons (Pahs) In Wildfire Smoke Accumulate On Indoor Materials And Create Post-Smoke Event Exposure Pathways, Aurélie Laguerre, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Wildfire smoke contains PAHs that, after infiltrating indoors, accumulate on indoor materials through particle deposition and partitioning from air. We report the magnitude and persistence of select surface associated PAHs on three common indoor materials: glass, cotton, and mechanical air filter media. Materials were loaded with PAHs through both spiking with standards and exposure to a wildfire smoke proxy. Loaded materials were aged indoors over ~4 months to determine PAH persistence. For materials spiked with standards, total PAH decay rates were 0.010±0.002, 0.025±0.005, and 0.051±0.009 d -1 , for mechanical air filter media, glass, and cotton, respectively. PAH decay on …

Functionalized Thermoplastic Polyurethane Nanofibers: An Innovative Triboelectric Energy Generator, Julia I. Salas, Diego De Leon, Sk Shamim Hasan Abir, Mohammed Jasim Uddin, Karen Lozano

Mechanical Engineering Faculty Publications

A triboelectric nanogenerator (TENG) is one of the most significantly innovative microdevices for built-in energy harvesting with wearable and portable electronics. In this study, the forcespinning technology was used to synthesize a nanofiber (NF) mat-based TENG. Polyvinylidene fluoride (PVDF) membrane was used as the negative triboelectric electrode/pole, and chemically designed and functionalized thermoplastic polyurethane (TPU) was used as the positive electrode/pole for the TENG. The electronic interference, sensitivity, and gate voltage of the synthesized microdevices were investigated using chemically modified bridging of multi-walled carbon nanotubes (MWCNT) with a TPU polymer repeating unit and bare TPU-based positive electrodes. The chemical functionality …

Modeling Of Asphalt Concrete For Cross-Anisotropic Visco-Elasticity And Heterogeneity, Zafrul Hakim Khan

Civil Engineering ETDs

Asphalt Concrete (AC) is a cross-anisotropic viscoelastic material. This study has developed a methodology to backcalculate the cross-anisotropic properties of the AC layer from the Falling Weight Deflectometer (FWD) sensor and pavement response data from embedded sensors inside a pavement section. This study has also developed a two-way coupled Multiscale Finite Element Model (MsFEM) with Phase Field Fracture (PFF) to study the microstructural heterogeneity and damage of the AC layer based on the actual field loadings. A Finite Difference Time Domain (FDTD) and Machine learning-based backcalculation algorithm were developed to determine the layer thickness and dielectric constant from air-coupled Ground …

Aerodynamic Dimpling For The Nose Cone Of A High-Power Competition Rocket, Graham Geoffrey Monroe

Mechanical Engineering ETDs

This thesis investigates nose cone dimpling for the reduction of the aerodynamic drag of a Level 3 High-Power amateur rocket. Two rocket launches were conducted. The first used a COTS nose cone with a smooth surface. A dimple distribution was created according to dimensions calculated by Sandia National Laboratories’ proprietary Right- Size Dimple Evaluator. A dimpled nose cone, designed with geometry matching the COTS component, was 3D printed. Axial acceleration and barometric pressure data, recorded by an onboard flight computer, were used to calculate and plot the drag coefficient as a function of the Reynolds number for the smooth and …

Main Effects Screening Study Of Fe/Kclo4 Thermal Battery Heat Pellet Resistive Activation, Bryan T. Steiner

Mechanical Engineering ETDs

Thermal battery iron-potassium perchlorate (Fe/KClO₄) heat pellets are often ignited by explosive igniters or heat paper. An alternative direct electrical ignition method via resistive heating is explored, which could improve thermal battery manufacturability and design flexibility. A main effects screening experiment was performed with the goal of confirming prior observed trends under more realistic test conditions and ranking the importance of design factors, to optimize future experiments and develop knowledge of the performance space. Relevant literature is examined to advance a theoretical understanding of resistive activation. Ignition sensitivity (go/no-go and time to ignition) and ignition energy are primary …

Control Of Fully-Actuated Aerial Manipulators And Omni-Directional Multirotors, Riley M. Mccarthy

Mechanical Engineering ETDs

This thesis details the system modeling, design, control, simulation, construction, and
testing of both a fully-actuated and omni-directional multirotor aerial system created
for the primary purpose of performing active tasks with their environment. This work
verifies the capabilities of both systems through empirical testing, and demonstrates
how through the use of new control methods and physical designs multirotors can
expand their purpose from passive inspection based tasks to active contact based
tasks. These systems take advantage of newly implemented control allocation features present in the PX4 flight control software, version 1.14. The use of which makes designing controllers for such …

Design, Fabrication And Characterization Of Zero Power Sensor/Harvester For Smart Grid Applications, Zeynel Guler

Mechanical Engineering ETDs

This study presents a flexible sensor/harvester device to be used in both electromagnetic sensing and energy harvesting applications for smart grids. When a current passes through a wire, the sensor detects the magnetic field created by that current. The sensor magnet interacts with the wire magnetic field resulting in a transfer of energy through the piezoelectric cantilever. Piezoelectric, conductive, magnetic, and magnetostrictive composite thin films were prepared to fabricate this device.

Initially, the magnet of the cantilever was optimized considering its shape, thickness, length, taper angle etc. via both simulations and experiments. Peak to peak voltage versus cantilever position graph …

Screw Dislocations In A Holed Wedge, Gregory T. Whiteside

Mechanical Engineering ETDs

A numerical code has been designed and implemented to find the stress at any material point in a holed-wedge material due to any number of crystal or real screw dislocations in the wedge. The code implements the image dislocation method together with the collocation point method to find stresses at any material point. We demonstrate that the combined analytical-numerical method (analytical with the image dislocations and numerical with the collocation-point method) is valid in that it produces stress fields giving rise to zero traction on free surfaces as well at an arbitrary number of collocation points on void surfaces. Additionally, …

A Preliminary Study On Floating Flexible Otec Cold Water Pipe, Nai Kuang Liang, Hai Kuan Peng

Journal of Marine Science and Technology–Taiwan

Ocean Thermal Energy Conversion (OTEC) requires a large amount of cold seawater. The traditional rigid pipe, semi-rigidly fixed onto the ship bottom is not easy to install and disassemble, so the Floating Flexible Cold Water Pipe (FFCWP) flexibly connected to the ship is proposed. A small FFCWP was designed, fabricated, and successfully installed and recovered in the sea. The flexible pipe adopts commercially available fire ventilation snake pipe. The pipe wall material strength must be improved in the future. Assuming that the drag coefficient Cd value is 1.5, a numerical calculation is employed to simulate the FFCWP attitude from the …

Machine Learning With Multi-Source Data To Predict And Explain Marine Pilot Occupational Accidents, Gokhan Camliyurt, Youngsoo Park, Daewon Kim, Won Sik Kang, Sangwon Park

Journal of Marine Science and Technology–Taiwan

Marine pilot occupational accidents during transfer to/from ships are the primary concern of the International Marine Pilots’ Association (IMPA) and industry professionals. There are multiple transfer methods for marine pilots, with the most common being the pilot boat. To reach the mother ship bridge, the following stages must be safely completed: car transfer, walking on the pier, pier to pilot boat, pilot transfer by boat, cutter to pilot ladder, mother ship freeboard climbing, and ship deck to the bridge. Each stage has its own risk. Previous accident records and expert opinions are commonly used to conduct a risk analysis and …

Evaluation Of Operational Performance Of Wusongkou Cruise Port Through Network Data Envelopment Analysis, Qian-Feng Wang, Guo-Ya Gan, Xin-Liang Ye, Hsuan-Shih Lee

Journal of Marine Science and Technology–Taiwan

As major hubs for cruise berthing and passenger transfers, cruise ports in China were developing rapidly in the years before the COVID-19 pandemic because of an ever-growing regional market. Wusongkou Cruise Port is the most important port for cruise ships in China, and this study evaluated the operational performance of this port during 2011–2020. To this end, two-stage network data envelopment analysis was conducted to evaluate the port’s operation performance; subsequently, the change trajectory of the port’s operational efficiency during 2011–2020 was determined, and the potential reasons for the identified changes are discussed. Finally, suggestions for improving the operational performance …

Air-Jet Bioprinting Of Stem Cell-Encapsulated Alginate Micro-Droplets For Organoid Biomanufacturing, Mirabella B. Stump

Electronic Theses and Dissertations

Biomanufactured 3D-organoids show promise for modeling and treating various conditions, particularly insulin-dependent diabetes mellitus (type-1 diabetes). Pancreatic islet organoids serve as sustainable sources of insulin-producing β-cells, potentially restoring insulin regulation in patients and providing a long-term solution for diabetes. Hydrogel droplet printing is an emerging technique in regenerative medicine due to its advantageous tunability and biocompatibility; however, challenges of consistency, quality control, and scalability persist. To address these issues, we developed a novel air-jetting based droplet bioprinting system for the generation of monodispersed alginate micro-droplets. The objective of this project was to incorporate human induced pluripotent stem cells (hiPSCs) into …

Fabrication And Characterization Of Flexible Microelectrode Arrays On Kapton Polyimide For Implantable Spinal Cord Stimulation Applications, Nabil Jamhour

Theses and Dissertations

Recent advances in spinal cord stimulation (SCS) technology have made a significant impact in the treatment of chronic pain which is a prevalent issue amongst 20% of the population in developed nations. A few medical device manufactures have developed SCS devices that have been studied in clinical environments and reported to be effective and safe for commercial use. However, the current SCS devices available are bulky, rigid, and still present infection, fibrosis, discomfort, pulse delivery challenges and other concerns for patients. In this study, flexible electrodes processed on Kapton® polyimide films by physical vapor and inkjet deposition are fabricated and …

Reconstructing Modis Aerosol Optical Depth And Exploring Dynamic And Influential Factors Of Aod Via Random Forest At The Global Scale, Bin Guo, Zheng Wang, Lin Pei, Xiaowei Zhu, Qiuji Chen, Haojie Wu, Wencai Zhang, Dingming Zhang

Mechanical and Materials Engineering Faculty Publications and Presentations

Aerosols pose a significant impact on the atmospheric environment and public health. Aerosol optical depth (AOD) is one of the essential parameters for quantifying aerosols. Currently, existing AOD products suffer from severe pixel value missing issue due to clouds and other interferences globally, which severely affects the accuracy of fine particulate matter estimation and related epidemics researches. At the global scale, this study first adopted population as one of the influencing factors of AOD, and fully considered the effects of humidity, surface pressure, cloud cover, and evapotranspiration on AOD. Meanwhile, the spatiotemporal resolution of meteorological data was promoted to improve …

Modeling Of Frontal Polymerization Of Carbon Fiber And Dicyclopentadiene Woven Composites With Stochastic Material Uncertainty, Ahmadreza Mohammad Sharifi, Dong-Jun Kwon, S. Z. H. Shah, Juhyeong Lee

Mechanical and Aerospace Engineering Faculty Publications

A novel finite element modeling framework is proposed for simulating dicyclopentadiene (DCPD) frontal polymerization in carbon fiber (CF) woven composites. A mesoscale CF/DCPD representative volume element (RVE) model was developed with two triggering directions, resulting in out-of-plane and in-plane DCPD polymerization. The Arrhenius equation coupled with a modified Prout-Tompkins autocatalytic model was used to evaluate the dynamic DCPD polymerization process. The rate and degree of DCPD cure were calculated by the material property uncertainties of DCPD with and without random void inclusions (3% used as a reference in this work). The DCPD frontal polymerization in CF/DCPD composite was strongly influenced …

Floating Wind Farm Experiments Through Scaling For Wake Characterization, Power Extraction, And Turbine Dynamics, Juliaan Bossuyt, OndˇRej FercˇÁk, Zein Sadek, Charles Meneveau, Dennice Gayme, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

In this study, wind and water tunnel experiments of turbulent wakes in a scaled floating wind farm are performed. Scaling of a floating wind farm with a scaling ratio of 1:400 is made possible by relaxing geometric scaling of the turbine platform system, such that the dynamic response can be correctly matched, and to allow for relaxing Froude scaling such that the Reynolds number can be kept large enough. Four dimensionless parameters, describing the relative importance of wind and wave loads compared to turbine inertia, are used to guide the scaled floater design. Free decay tests of the pitch and …

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, …