Mechanical Engineering Commons^™

Designing A Nano-Drone With Hybrid Structural Energy Storage, Ann Klindworth, Jared Cornett, Kyle Leifheit, Joseph Dejacimo

Williams Honors College, Honors Research Projects

The Advanced Energy and Sensor Lab at the University of Akron has been working to develop a working flow battery that replaces today’s solid batteries. The objective of this senior design project was to replace the conventional lithium-ion battery as the energy storage component in nano-copters with a newly designed hybrid structural battery. In the design, the nano-copter needed to be mechanically supported and store enough energy for flying. In order to accomplish this, the nano-copter weight was reduced so that the flight range could be significantly increased. Therefore, the project was broken into two major parts. The first was …

An Adapted Approach To Process Mapping Across Alloy Systems And Additive Manufacturing Processes, Luke Charles Sheridan

Browse all Theses and Dissertations

The continually growing market for metal components fabricated using additive manufacturing (AM) processes has called for a greater understanding of the effects of process variables on the melt pool geometry and microstructure in manufactured components for various alloy systems. Process Mapping is a general approach that traces the influence of process parameters to thermal behavior and feature development during AM processing. Previous work has focused mainly on Ti-6Al-4V (Ti64), but this work uses novel mathematical derivations and adapted process mapping methodologies to construct new geometric, thermal, and microstructural process maps for Ti64 and two nickel superalloy material systems. This work …

Torque Accuracy Improvement Via Explicit Torque Feedback Control For Internal Combustion Spark Ignition Engines, Anwar Alkeilani

Wayne State University Dissertations

At the present time, both control and estimation accuracies of engine torque are causes for under-achieving optimal drivability and performance in today’s production vehicles. The major focus in this area has been to enhance torque estimation and control accuracies using existing open-loop torque control and estimation structures. Such an approach does not guarantee optimum torque tracking accuracy and optimum estimation accuracy due to air flow and efficiencies estimations errors. Furthermore, current approach overlooks the fast torque path tracking which does not have any related feedback. Recently, explicit torque feedback control has been proposed in the literature using either estimated or …

Electrocatalysis In Li-S Batteries, Hesham I. Al Salem

Wayne State University Dissertations

Stabilizing polysulfide-shuttle process while ensuring high sulfur loading holds the key to realize high theoretical energy density (2500 Wh/kg) of lithium-sulfur (Li-S) batteries. Though several carbon based porous materials have been used as host structures for sulfur and its intermediate polysulfides, the week adsorption of polysulfides on carbon surface and its poor reaction kinetics limits them from practical application. Here, we preset a novel ‘electcatalysis’ approach to stabilize polysulfide shuttle process and also enhance its red-ox kinetics. As a proof of concept, we have studied in-detail using conventional electrocatalyst i.e Pt/graphene composite, further the same extended to cost-effective electrocatalysts such …

Combustion, Ionization And Sporadic Pre-Ignition In A Turbocharged Gasoline Direct Injection Engine., Shenouda Mekhael

Wayne State University Dissertations

This research is focused on the use of ionization of combustion products in hydrocarbons-air flames to gain a better understanding of the combustion process in turbocharged gasoline direct injection engines. A GM 2.0 L Ecotec GDI-T engine is used in this investigation. The ion current is measured simultaneously by two in-cylinder combustion sensors: the spark plug and the fuel injector. The characteristics of the ion current signals produced by the two sensors are analyzed and correlated with the characteristics of the rate of heat release computed from the cylinder gas pressure. Since this is the first time for the fuel …

Static And Dynamic Behavior Of Carbon Fiber Reinforced Aluminum (Carall) Laminates, Gurpinder Singh Dhaliwal

Wayne State University Dissertations

STATIC AND DYNAMIC BEHAVIOUR OF CARBON FIBER REINFORCED ALUMINUM (CARALL) LAMINATES

by

GURPINDER SINGH DHALIWAL

Advisor: Dr. Golam Newaz

Major: Mechanical Engineering

Degree: Doctor of Philosophy

The main aim of this research work was to investigate the static and dynamic properties of carbon fiber reinforced aluminum laminates cured without using any external adhesive and acid treatment of aluminum layers. A comprehensive study was undertaken to study the effect of adding epoxy resin rich polyester synthetic surface veil cloth layers on the failure modes and flexural and tensile response of these fiber metal laminates (FMLs). The main purpose of adding veil …

A Multi-Scale Approach To Study Solid Oxide Fuel Cells: From Mechanical Properties And Crystal Structure Of The Cell's Materials To The Development Of An Interactive And Interconnected Educational Tool, Amjad Aman

Electronic Theses and Dissertations

Solid Oxide Fuel Cells are energy conversion devices that convert chemical energy of a fuel directly into electrical energy. They are known for being fuel-flexible, have minimal harmful emissions, ideal for combined heat and power applications, highly energy-efficient when combined with gas or steam turbines. The current challenges facing the widespread adoption these fuel cells include cost reduction, long-term testing of fully integrated systems, improving the fuel cell stack and system performance, and studies related to reliability, robustness and durability. The goal of this dissertation is to further the understanding of the mechanical properties and crystal structure of materials used …

In Situ Microscopy Of The Self-Assembly Of Branched Nanocrystals In Solution, Eli Sutter, Peter Sutter, Alexei V. Tkachenko, Roman Krahne, Joost De Graaf, Milena Arciniegas, Liberato Manna

Department of Mechanical and Materials Engineering: Faculty Publications

Solution-phase self-assembly of nanocrystals into mesoscale structures is a promising strategy for constructing functional materials from nanoscale components. Liquid environments are key to self-assembly since they allow suspended nanocrystals to diffuse and interact freely, but they also complicate experiments. Real-time observations with single-particle resolution could have transformative impact on our understanding of nanocrystal self-assembly. Here we use real-time in situ imaging by liquid-cell electron microscopy to elucidate the nucleation and growth mechanism and properties of linear chains of octapod-shaped nanocrystals in their native solution environment. Statistical mechanics modelling based on these observations and using the measured chain-length distribution clarifies the …

Influence Of Shear Stress Magnitude And Direction On Atherosclerotic Plaque Composition, Ryan M. Pedrigi, Vikram V. Mehta, Sandra M. Bovens, Zahra Mohri, Christian Bo Poulsen, Willy Gsell, Jordi L. Tremoleda, Leila Towhidi, Ranil De Silva, Enrico Petretto, Rob Krams

Department of Mechanical and Materials Engineering: Faculty Publications

The precise flow characteristics that promote different atherosclerotic plaque types remain unclear. We previously developed a blood flow-modifying cuff for ApoE^−/− mice that induces the development of advanced plaques with vulnerable and stable features upstream and downstream of the cuff, respectively. Herein, we sought to test the hypothesis that changes in flow magnitude promote formation of the upstream (vulnerable) plaque, whereas altered flow direction is important for development of the downstream (stable) plaque. We instrumented ApoE^−/− mice (n=7) with a cuff around the left carotid artery and imaged them with micro-CT (39.6 μm resolution) eight to nine weeks …

Rotary Vegetation System: Can It Speed Up The Absorption Of Indoor Air Pollutants?, Yusuke Nakamura

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Corrosion Protection Systems In Offshore Structures, Hristo Ivanov

Williams Honors College, Honors Research Projects

Corrosion plays a pivotal role in the engineering world. Engineers of all disciplines must consider the dangers that this phenomenon can incur. Interestingly, corrosion mitigation is not a topic that is addressed in most academic curricula. The goal of this paper is to give engineering students a brief introduction into corrosion and some of the prevention techniques commonly used today.

The design of a corrosion protection system for offshore structures is discussed in order to illustrate how these techniques can be utilized even in the most extreme environments. First, the driving force behind corrosion is examined, introducing the basic mechanics …

Optimal Configuration And Tuning Of Wave Energy Converter Arrays, Emma Edwards

Link Foundation Ocean Engineering and Instrumentation Fellowship Reports

Power from ocean waves is becoming an increasingly attractive option as a source of renewable energy. Ocean waves are more reliable and predictable than sun and wind, and have a higher energy density [1]. There are locations where solar and wind energy would not be viable, due to the large amount of space they take up, either on land (solar) or above ground (wind). In addition, wave energy devices are less of a visual deterrent than wind turbines, and wave energy is particularly attractive for areas with a lot of coast line. Wave energy is still in its infancy, though, …

A Shipboard Instrument For Underway Estimates Of Marine N2 Fixation, Weiyi Tang

Link Foundation Ocean Engineering and Instrumentation Fellowship Reports

Marine N2 fixation converts nitrogen gas into ammonia and accounts for the largest external nitrogen input to the oceans1. Since large portions of the global oceans are nitrogen deficient, marine N2 fixation can relieve the nitrogen limitation, thereby increasing the growth of phytoplankton and stimulating biological uptake of atmospheric carbon dioxide2,3,4. However, the magnitude and distribution of marine N2 fixation are poorly constrained5. In addition, the environmental controls on marine N2 fixation remain elusive6. This situation is in part attributable to the limited number of observations and poor coverage of marine N2 fixation measurements. Current observations rely on discrete sampling …

Aerodynamic And Modal Analyses Of Small Scale Horizontal Axis Wind Turbine With Various Numbers Of Blade Design, Emile Maroha

College of Graduate Studies: Theses & Dissertations

With the global energy demand rising to unprecedented numbers, the need for alternative energy sources is ever prevalent. Wind energy is the most alternative renewable sources today due to its year-round availability and pollution-free nature. Horizontal Axis Wind Turbines (HAWT) are the most popular because of their higher efficiency. The aerodynamic characteristics and vibration of small scale HAWT with various numbers of blade design have been investigated in this numerical study in order to improve its performance. SolidWorks was used for designing CAD models, and ANSYS software was used to study the dynamic flow around the turbine as well as …

Low-Velocity Impact To High-Temperature Low-Sag Overhead Conductors, Daniel Halka Waters

Electronic Theses and Dissertations

High-Temperature Low-Sag (HTLS) conductors, such as Aluminum Conductor Composite Core (ACCC), improve infrastructure to support the delivery of power to meet the nation's increasing demand for electricity. Their response to low-velocity impacts during transportation, installation or in service, however, has not been addressed in the past. Therefore, this study investigates both experimentally and numerically mechanical effects associated with transverse low-velocity impacts on energy dissipation by the conductors subjected to either free or constrained end conditions and large axial tensile loads. Impact experiments were conducted using a newly designed and manufactured testing apparatus. The experimental work was strongly supported by non-linear …

Inlet Distortion Effects On The Unsteady Aerodynamics Of A Transonic Fan Stage, Daniel Oliver Reilly

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A computational study was conducted to understand the influence of aircraft inlet distortion flow on the unsteady aerodynamic loading of a gas turbine fan stage. A single stage, transonic fan design with no inlet guide vanes was modeled with a commercial, computational fluid dynamics solver, STAR-CCM+, using the harmonic balance technique. The baseline inlet boundary condition applied to the model is consistent with that of a homeomorphic variant of the M2129 S-duct, and exhibited stagnation pressure distortion and a swirl pattern. The baseline inlet flow was decomposed and parameterized into a set of inlet boundary conditions which were individually applied …

The Effect Of Laser Power And Scan Speed On Melt Pool Characteristics Of Pure Titanium And Ti-6al-4v Alloy For Selective Laser Melting, Chandrakanth Kusuma

Browse all Theses and Dissertations

Selective Laser Melting (SLM) is an additive manufacturing (AM) technique that creates complex parts by selectively melting metal powder layer-by-layer. In SLM, the process parameters decide the quality of the fabricated component. In this study, single beads of commercially pure titanium (CP-Ti) and Ti-6Al-4V alloy are melted on a substrate of the same material as powder using an in-house built SLM machine. Multiple combinations of laser power and scan speed are used for single bead fabrication while the laser beam diameter and powder layer thickness are kept constant. This experimental study investigates the influence of laser power, scan speed and …

Cfd Prediction And Simulation Of A Pumpjet Propulsor, Lin Lu, Guang Pan, Prasanta K. Sahoo

Ocean Engineering and Marine Sciences Faculty Publications

In this study an attempt has been made to study the hydrodynamic performance of pumpjet propulsor. Numerical investigation based on the Reynolds Averaged NaviereStokes (RANS) computational fluid dynamics (CFD) method has been carried out. The structured grid and SST keu turbulence model have been applied. The numerical simulations of open water performance of marine propeller E779A are carried out with different advance ratios to verify the numerical simulation method. Results show that the thrust and the torque are in good agreements with experimental data. The grid independent inspection is applied to verify accuracy of numerical simulation grid. The numerical predictions …

Anisotropic Electrical Response Of Carbon Fiber Reinforced Composite Materials, Mohammad Faisal Haider

Theses and Dissertations

Composites materials are often subjected to multi-physical conditions in different applications where, in addition to mechanical loads, they also need to sustain other types of loads such as electrical currents. The multi-physical behavior of composites needs to be understood and analyzed to facilitate new multi-functional material design. An essential first step towards this goal is to understand how multi-physics properties depend on local details (e.g. micro-structure). Composite materials have heterogeneous electrical properties (carbon/epoxy) at the local level that can be different at the global level. To conduct the multi-physics study, the electrical signal is employed to the composite sample for …

Deformation Of Multifunctional Materials At Various Time And Length Scales: A Dic-Based Study, Behrad Koohbor

Theses and Dissertations

The focus in the present work is to explore and characterize the underlying deformation and failure mechanisms in multifunctional materials including woven composites and polymeric foams, using full-field measurements. Attention has been especially drawn towards the challenges associated with characterizing these materials at extreme length and time scales, and investigating the advantages of full-field measurements to resolve the existing limitations. Accordingly, the current limitations in the study of dynamic deformation response of low-impedance materials are identified. An approach based on the general stress equilibrium is presented and successfully implemented to include the concurrent effects of inertia and material compressibility into …

The Effects Of Micro-Dimple Texture On The Friction And Thermal Behavior Of A Point Contact, Utsav Kamleshbhai Parmar

Browse all Theses and Dissertations

This study investigates the effects of the micro-dimple texture on the friction and surface temperature performances of a ball-on-disk contact, operating under the speed and load ranges that cover typical gearing applications. Circular shaped micro-dimple arrays with different dimple center distances and dimple depths are implemented on the ball surface to quantify the impacts of these two parameters on the friction coefficient and the maximum ball surface temperature. In addition, the contacts of three surface texture combinations, namely micro-dimpled and polished ball surface versus polished disk surface, polished ball surface versus polished disk surface and ground ball surface versus ground …

Elucidating The Role Of Microstructure, Texture, And Microtexture On The Dwell Fatigue Response Of Ti-6al-4v, Alec Mitchell Blankenship

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Ambient temperature dwell sensitivity is known to be deleterious to the fatigue response of near-alpha titanium alloys. Dwell fatigue refers to the presence of a sustained hold at peak stress as opposed to the continuous variation of normal cyclic fatigue loading. This reduction in failure life-times from dwell loading is attributed to early crack nucleation and faster crack propagation. The degradation is the result of plastic anisotropy on the microstructural scale along with tendency of titanium alloys to creep at low temperatures at stresses well below the 0.2% offset yield strength. Despite being the most widely used titanium alloy, Ti-6Al-4V …

On The Experimental Evaluation Of Loss Production And Reduction In A Highly Loaded Low Pressure Turbine Cascade, Philip Steven Bear

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Improvements in turbine design methods have resulted in the development of blade profiles with both high lift and good Reynolds lapse characteristics. An increase in aerodynamic loading of blades in the low pressure turbine section of aircraft gas turbine engines has the potential to reduce engine weight or increase power extraction. Increased blade loading means larger pressure gradients and increased secondary losses near the endwall. Prior work has emphasized the importance of reducing these losses if highly loaded blades are to be utilized. The present study analyzes the secondary flow field of the front-loaded low-pressure turbine blade designated L2F with …

Biomimetic Substrate Control Of Cellular Mechanotransduction, Mohammad Nahid Andalib, Yuris A. Dzenis, Henry J. Donahue, Jung Yul Lim

Department of Mechanical and Materials Engineering: Faculty Publications

Extracellular mechanophysical signals from both static substrate cue and dynamic mechanical loading have strong potential to regulate cell functions. Most of the studies have adopted either static or dynamic cue and shown that each cue can regulate cell adhesion, spreading, migration, proliferation, lineage commitment, and differentiation. However, there is limited information on the integrative control of cell functions by the static and dynamic mechanophysical signals. For example, a majority of dynamic loading studies have tested mechanical stimulation of cells utilizing cultures on flat surfaces without any surface modification. While these approaches have provided significant information on cell mechanotransduction, obtained outcomes …

Characterizing The Boundary Lateral To The Shear Direction Of Deformation Twins In Magnesium, Y. Liu, N. Li, S. Shao, M. Gong, J Wang, R.J. Mccabe, Y. Jiang, C.N. Tome

Department of Mechanical and Materials Engineering: Faculty Publications

The three-dimensional nature of twins, especially the atomic structures and motion mechanisms of the boundary lateral to the shear direction of the twin, has never been characterized at the atomic level, because such boundary is, in principle, crystallographically unobservable.We thus refer to it here as the dark side of the twin. Here, using high-resolution transmission electron microscopy and atomistic simulations, we characterize the dark side of {1012} deformation twins in magnesium. It is found that the dark side is serrated and comprised of {1012} coherent twin boundaries and semi-coherent twist prismatic–prismatic {2110} boundaries that control twin growth. The conclusions of …

Stress-Dependent Ultrasonic Scattering In Polycrystalline Materials, Christopher M. Kube, Christopher A Turner

Department of Mechanical and Materials Engineering: Faculty Publications

Stress-dependent elastic moduli of polycrystalline materials are used in a statistically based model for the scattering of ultrasonic waves from randomly oriented grains that are members of a stressed polycrystal. The stress is assumed to be homogeneous and can be either residual or generated from external loads. The stress-dependent elastic properties are incorporated into the definition of the differential scattering cross-section, which defines how strongly an incident wave is scattered into various directions. Nine stress-dependent differential scattering cross-sections or scattering coefficients are defined to include all possibilities of incident and scattered waves, which can be either longitudinal or (two) transverse …

Graphene Platform For Neural Regenerative Medicine, Tasneem Bouzid, Alexander Sinitskii, Jung Yul Lim

Department of Mechanical and Materials Engineering: Faculty Publications

Graphene is a material composed of a single layer of carbon atoms arranged in a two-dimensional honeycomb lattice. The unique electrical, optical, thermal, and mechanical properties of graphene are extensively exploited for various applications in electronics, energy, and sensors. Studies also proposed the potential of graphene for biomedical applications. The intrinsic characteristics of graphene and its availability for chemical and physical modifications make graphene a promising vehicle for various biomedical applications including drug delivery, bioimaging, disease diagnostics, etc. The chemical structure of graphene and, in turn, its functionality, can be altered by attaching functional groups, which not only modify the …

Mode-Converted Ultrasonic Scattering In Polycrystals With Elongated Grains, Andrea P. Arguelles, Christopher M. Kube, Ping Hu, Joseph A. Turner

Department of Mechanical and Materials Engineering: Faculty Publications

Elastic wave scattering is used to study polycrystalline media for a wide range of applications. Received signals, which include scattering from the randomly oriented grains comprising the polycrystal, contain information from which useful microstructural parameters may often be inferred. Recently, a mode-converted diffuse ultrasonic scattering model was developed for evaluating the scattered response of a transverse wave from an incident longitudinal wave in a polycrystalline medium containing equiaxed single-phase grains with cubic elastic symmetry. In this article, that theoretical mode-converted scattering model is modified to account for grain elongation within the sample. The model shows the dependence on scattering angle …

Enhancing Stability And Efficiency Of Perovskite Solar Cells With Crosslinkable Silane-Functionalized And Doped Fullerene, Yang Bai, Qingfeng Dong, Yuchuan Shao, Yehao Deng, Qi Wang, Liang Shen, Dong Wang, Wei Wei, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

The instability of hybrid perovskite materials due to water and moisture arises as one major challenge to be addressed before any practical application of the demonstrated high efficiency perovskite solar cells. Here we report a facile strategy that can simultaneously enhance the stability and efficiency of p–i–n planar heterojunction-structure perovskite devices. Crosslinkable silane molecules with hydrophobic functional groups are bonded onto fullerene to make the fullerene layer highly water-resistant. Methylammonium iodide is introduced in the fullerene layer for n-doping via anion-induced electron transfer, resulting in dramatically increased conductivity over 100-fold. With crosslinkable silane-functionalized and doped fullerene electron transport layer, the …

Stabilized Wide Bandgap MapbbrXI3– X Perovskite By Enhanced Grain Size And Improved Crystallinity, Miao Hu, Cheng Bi, Yongbo Yuan, Yang Bai, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

Methylammonium lead trihalide perovskite (MAPbX₃, where MA is methylammonium, and X is a halide)-based solar cells have been intensively investigated recently, with the demonstrated certified solar power conversion efficiency (PCE) exceeding 20%. To further boost the PCE to beyond the Schockley–Queisser limit, tandem structured solar cells have been investigated based on integrating MAPbX₃ and low bandgap solar cells. However, the efficiency of the two-terminal integrated perovskite-silicon tandem cells is still low. The best reported efficiency of 13.7% for this type of tandem cells is far smaller than the individual cells yet, partially due to the limited performance …