Index Catalog // ScholarsArchive@OSU

Generalized Preconditioning to Accelerate Simulations with Large Multiphase Chemical Kinetics Models

Creator:: Walker, Anthony S.
Abstract:: Combustion emissions produced from burning real transportation fuels have many environmental impacts. However, detailed chemistry across multiple phases, time scales, and thermodynamic conditions make predicting combustion emissions challenging. Detailed modeling of the gas phase alone is prohibitively expensive, due to the large size and stiffness of the kinetic models. The...
Resource Type:: Dissertation

Numerical Modeling of Powder Metallurgy Hot Isostatic Pressing

Creator:: Sobhani, Samaneh
Abstract:: Powder Metallurgy Hot Isostatic Pressing (PM-HIP) is a widely recognized powder metallurgy manufacturing process to produce near-net-shape and net-shape components. During general PM-HIP processes the metal powders are filled within a capsule (die), heated and loaded with high pressure simultaneously, and solidified to form the final product. Due to the...
Resource Type:: Dissertation

Multi-modal sensing data fusion for machining and additive manufacturing

Creator:: Fu, Xianzhe
Abstract:: With the increased demand for high-quality products, reliable and robust process monitoring has become a key capability for modern manufacturing systems. Through sensors installed in the machinery, the real-time information was measured to assess the state of the processes. The measured data can be used to infer the mechanical, material,...
Resource Type:: Dissertation

High Temperature Electrical Properties of Ceria-Based Ceramics for Use as Electrodes in Magnetohydrodynamic Power Generators

Creator:: Bowen, Michael S.
Abstract:: Determining the electrical properties of ceria-based materials is important for their use as electrodes in hot-wall magnetohydrodynamic (MHD) power generators with wall temperatures greater than 1500 ̊C. The electrical conductivity of a material can be used in models for predicting the performance of generator designs. More specifically, the temperature dependent...
Resource Type:: Dissertation

Development and validation of acoustic measurement techniques for void fraction in concentric annular geometries

Creator:: Tost, Brian C.
Abstract:: This work investigates the acoustic velocity of gas-liquid mixtures in vertical, co-current flow in a concentric annulus. Acoustic velocity shows promise as a detection parameter for the presence and amount of gas in a liquid flow because of its high sensitivity to gas void fraction in a gas-liquid mixture. However,...
Resource Type:: Dissertation

Optical sensing and metrology for on-machine surface inspection in manufacturing processes

Creator:: Lee, Eddie T.
Abstract:: Optical sensing technologies are pivotal in the manufacturing process, specifically in defect detection, tool condition estimation, and monitoring. The research aims to enhance the accuracy, efficiency, and reliability of manufacturing metrology by employing optical sensing technologies, such as laser profilometers and image processing techniques. The dissertation proposes intelligent and flexible...
Resource Type:: Dissertation

Experimental Study of the Impact of Physical and Chemical Properties on Smoldering Combustion in Natural Fuels

Creator:: Smucker, Benjamin
Abstract:: Smoldering combustion in wildland fires is difficult to extinguish, can transition to flaming combustion, and produces a significant amount of pollutants. It is necessary to understand parameters controlling smoldering in order to help predict the smoldering behavior and potentially mitigate these hazards. The wide variety of natural fuels that occur...
Resource Type:: Dissertation

The Effect of Isothermal Aging on the Development of Long-Range Order in Ni-based Alloys

Creator:: Aerne, Nicholas S. J.
Abstract:: Nickel (Ni)-based alloys with a high chromium (Cr) content are frequently employed in applications where elevated temperatures and/or corrosive environments are present due to their excellent corrosion resistance and mechanical properties. However, a gap exists around the formation, and kinetics of long-range order (LRO) Ni2Cr phase in both model binary...
Resource Type:: Dissertation

Process Physics, Strategies and Economics in Metal Additive Manufacturing and Digital Microstructural Control for Energy and Chemical Process Components

Creator:: Manoharan, Sriram
Abstract:: Advances in plant construction within the energy and chemical process industries require inexpensive process intensification (PI) technology as a means to reduce plant size for enabling modular construction. One form of PI is microchannel process technology where arrays of microchannels, having hydraulic diameters on the order of 0.1 to 1...
Resource Type:: Dissertation

Computational Modeling of Smoldering Combustion in Wildland Fuels

Creator:: Jayasuriya, Waduge Jayani A.
Abstract:: Smoldering combustion in wildland fires is a critical phenomenon that needs in-depth study because it can initiate with weaker ignition sources, can persist for long periods, is difficult to suppress, and can transit to flaming combustion. Cellulose, hemicellulose, and lignin are the major organic constituents within biomass, in varying proportions...
Resource Type:: Dissertation

Tracking of Melt Pool Motion Using Numerical Analysis of Laser Powder Bed Fusion

Creator:: Cox, Bryce
Abstract:: Laser Powder Bed Fusion (LPBF) is a process commonly used to create additively manufactured metal parts. The flexibility and complexity allowed by the LPBF process provides opportunity for significant advancement in multiple industries as parts can be customized in shape and function for specific needs. These benefits can be compounded...
Resource Type:: Dissertation

Ignition of Fuel Beds by Firebrands

Creator:: Bean, Derek R.
Abstract:: The severity of wildfires around the globe is increasing. At the same time, urban development is expanding outward into areas where severe fires occur. There is an increased risk of home loss to fires in areas where severe fires and urban expansion meet. Ignition of homes or nearby fuel is...
Resource Type:: Dissertation

Modeling Methods for Hydraulic Fracturing Wastewater Treatment Applications

Creator:: O'Hern, Hannah
Abstract:: Modeling of hydraulic fracturing wastewater treatment systems must be very accurate so it can be used for real-time modeling and control of the process. The treatment of hydraulic fracturing wastewater is complex because of the variability of the composition of hydraulic fracturing wastewater. In this work, literature review of hydraulic...
Resource Type:: Dissertation

Empirical Characterization and Data-Driven Optimization of Water-Energy Systems

Creator:: Elhashimi, Mohammed A.
Abstract:: The accelerated development in water-energy systems calls for advanced modeling and optimization tools to improve technologies’ performance. Water desalination is a manifestation of water-energy system that is challenged by different operational constraints. The scarcity and uneven distribution of freshwater around the world makes water desalination an indispensable process to address...
Resource Type:: Dissertation

Thermal Actuation and Atomization for Desalination Systems

Creator:: Sharma, Deepak
Abstract:: Desalination stands for removing salt from saline water, and produce freshwater. Desalination technologies have been envisioned as a potential solution for freshwater production from oceans as an immense source of water acquiring 97% earth’s water, and 75% of earth’s surface. However, one third of world’s population face water scarcity every...
Resource Type:: Dissertation

Study of Energy Harvesting Performance of Oscillating Airfoils using a Discrete Vortex Model

Creator:: Kamrani Fard, Kiana
Abstract:: The energy harvesting performance of oscillating airfoils is studied using a discrete vortex model (DVM) with a leading-edge separation criterion. The airfoil undergoes a combined sinusoidal heaving and pitching motion at reduced frequencies of k = 0.06 − 0.16, with heaving amplitude of h0 = 0.5c, and pitching amplitude of...
Resource Type:: Dissertation

An Information Modeling Framework for Support of Sustainable Manufacturing System Design Decision Making

Creator:: Shankar Raman, Arvind
Abstract:: Manufacturing technology has continuously evolved and advanced over the past century; this has led to an increase in the production of consumer and industrial goods driven by simultaneous growth in population and wealth. Despite the resulting economic and labor growth, environmental impacts of manufacturing have increased dramatically due to the...
Resource Type:: Dissertation

Optical sensing for nondestructive structural evaluation and additive manufacturing process monitoring

Creator:: Hu, Xiaochen
Abstract:: Sensing is a significant engineering science which quantify parameters from the physical world and discover the physics running behind the measurement process. Optical sensing makes use of electromagnetic waves from infrared to ultraviolet on the light spectrum as a medium to measure variables, such as position, temperature and strain. Image...
Resource Type:: Dissertation

Identifying the Effects of Combustion Products, Turbulent Fluctuations, and Delivered Energy on Ignition Characteristics of Forced Ignition of Jet-A/air Mixtures

Creator:: Teope, Kaz I.
Abstract:: The operation of gas turbine engines depends on the reliable ignition of fuel/air mixtures. Gas turbine engines are commonly used as commercial and military aviation power plants. However, consistent ignition within gas turbine engines is still a problem, especially for more challenging operating conditions such as emergency operations. This work...
Resource Type:: Dissertation

A Framework to Evaluate the Risk of Human- and Component-related Vulnerability Interactions

Creator:: Irshad, Lukman
Abstract:: Most accidents and malfunctions in complex engineered systems are attributed to human error. However, a closer inspection would reveal that such mishaps often emerge as a result of poor design and human- and component-related vulnerabilities acting together. To fully understand and mitigate potential risks, the effects of such interactions between...
Resource Type:: Dissertation

Pre-Prototyping Framework: An Early Design Prototyping Methodology for Human-Centered Products and Workplaces

Creator:: Ahmed, Salman
Abstract:: Prototyping is a crucial step in product design and development, but it is also known as the highest sunk cost. The top 20 Research and Development (R&D) department spends 142 billion dollars, yet 40 to 46 percent of this money goes into developing products that cannot even make to the...
Resource Type:: Dissertation

Data-Driven Environmentally Sustainable Product Design: A Shift Toward Increased use of Sustainable Design Activities in the Early Design Phase

Creator:: Ferrero, Vincenzo J.
Abstract:: Modern product design drives the boundaries of innovation by encompassing complex Design-for-X objectives, and the inclusion of multidimensional stakeholders. This growing complexity in product design has left design teams unequipped, as classical design theory is bounded by designer experience, expertise, and cognition. One novel approach to tackling product complexity is...
Resource Type:: Dissertation

Accelerating Power-to-Gas Energy Storage Through PEM Electrolyzer Development and Technoeconomic Forecasting

Creator:: Taie, Zachary
Abstract:: There is strong interest in the energy community to develop technologies that can diffuse low-cost, renewably generated electricity into difficult and slow to decarbonize sectors. One of the emerging areas of interest is renewable natural gas (RNG). RNG has low or no associated net greenhouse gas emissions and can be...
Resource Type:: Dissertation

A Computational Framework for Resilience-Informed Design

Creator:: Hulse, Daniel E.
Abstract:: It is desirable for complex engineered systems to perform missions efficiently and economically, even when these missions' complex, variable, long-term operational profiles make it likely for hazards to arise. It is thus important to design these systems to be resilient so that they will actively prevent and recover from hazards...
Resource Type:: Dissertation

Hybrid Statistical and Engineering Optimization Architectures in Early Multidisciplinary Designs of Resilience and Expensive Black-box Complex Systems

Creator:: Biswas, Arpan
Abstract:: Practical engineering design problems are generally multi-disciplinary with limited budget and high risk in terms of life loss, economic resources, etc. In the early phase of such problems, selection of true efficient designs is desired while minimizing overall design cost by avoiding expensive search processes. However, the task is difficult...
Resource Type:: Dissertation

The Structural Characteristics of Robustness in Large-Scale Complex Engineered Systems

Creator:: Walsh, Hannah S.
Abstract:: Modern engineered systems are increasingly integrated into society, decentralized, and interconnected. However, scale and complexity create unique challenges in system design, such as emergent behavior and unintended consequences. This work investigates the structural characteristics of robustness in complex engineered systems by identifying patterns of under-recognized vulnerabilities at various levels of...
Resource Type:: Dissertation

Achieving Transparency in Human-Collective Systems

Creator:: Roundtree, Karina A.
Abstract:: Collective robotic systems are biologically-inspired and exhibit behaviors found in spatial swarms (e.g., fish), colonies (e.g., ants), or a combination of both (e.g., bees). Collective robotic system popularity continues to increase due to their apparent global intelligence and emergent behaviors. Many applications can benefit from the incorporation of collectives, including...
Resource Type:: Dissertation

Investigation of In-tube Non-equilibrium Condensation of Low Global Warming Potential Refrigerants

Creator:: Jacob, Tabeel A.
Abstract:: This work investigates the in-tube condensation of low global warming potential (GWP) zeotropic refrigerant mixtures R448A, R450A, R452A, R454B and R454C. These refrigerants have been proposed for a wide range of commercial heating, ventilation, air-conditioning applications, but their heat and momentum transport phenomenon were not well understood. Thus, in this...
Resource Type:: Dissertation

Geometry of Locomotion

Creator:: Ramasamy, Suresh
Abstract:: Many animals and robots move through the world by coupling cyclical changes in shape called gaits to an interaction with the environment. Because mobility is an important aspect of such robots, a key metric when evaluating design and performance of mobile robots is the efficiency of their optimal gaits. The...
Resource Type:: Dissertation

Turbulent Heat Transfer of Supercritical Carbon Dioxide in the Proximity of the Pseudo-Critical Point with Non-Uniform Heat Flux Boundary Conditions

Creator:: Jajja, Saad A.
Abstract:: Seven decades of supercritical heat transfer research have not seen an attempt to characterize turbulent thermal transport in internal flows subject to asymmetric heating. Existing heat transfer models therefore do not account for phenomena that dictates thermal transport, in the proximity of the pseudo-critical point, for non-uniform heating. Additionally, past...
Resource Type:: Dissertation

Development of a Boiling Surface Effectiveness Parameter by Modeling and Quantifying the Net Coolant Flow Rate

Creator:: Harrison, Matt
Abstract:: Boiling dynamics and related heat transfer mechanisms have been widely studied for several decades. During that time, incredible progress has been made on quantifying bubble departure phenomena including growth rate, departure frequency, associated natural and forced convection, and radiation additions to the overall heat transfer rate. With this, the thermal...
Resource Type:: Dissertation

Structure and Actuation of Cephalopod-Inspired Soft Robots

Creator:: Olson, Gina M.
Abstract:: Cephalopod-inspired soft robot arms have been studied as a new type of manipulator. These arms have been proposed for reach and grab tasks, underwater locomotion via swimming and walking, and robotic surgery. However, the capabilities of existing soft arms are limited to simple motions and light loads. Arm design has...
Resource Type:: Dissertation

Analysis of the Effects of Combustion Products on Forced Ignition and Turbulent Flame Propagation

Creator:: Bonebrake, Jonathan M.
Abstract:: Practical combustion devices frequently rely upon forced ignition of turbulent fuel/oxidizer mixtures that also contain the product species of combustion. Examples of this include engines that use exhaust gas recirculation (EGR), inter-turbine burners in aircraft engines, and other systems the utilize staged combustion. In this work, the effects of major...
Resource Type:: Dissertation

On the Euler-Lagrange Modeling of Particle-laden Turbulent Flows

Creator:: Pakseresht, Pedram
Abstract:: Particle-laden turbulent flows, wherein a large number of small size particles are dispersed in a fluid, are widely encountered in environmental and industrial applications. Understanding their underlying physics, making predictions without performing expensive experiments, and ultimately optimizing the systems carrying such flows, require accurate and robust modelling tools. The Euler-Lagrange...
Resource Type:: Dissertation

Vortical Structures in Transition to Turbulence through Randomly Packed Porous Media: Scale, Energy, and Mixing Characteristics

Creator:: Mohammadi Ziazi, Reza
Abstract:: Vortical structures are the driving mechanism of transition to turbulence in porous media requiring adequately resolved observations along with analysis of the scale and energy of ﬂow within the pores. Of speciﬁc interest is to understand the vortex dynamics, energy, and turbulent mixing and transport properties in the scale of...
Resource Type:: Dissertation

Assessing Mass Diffusion Modeling in Premixed Flames

Creator:: Fillo, Aaron J.
Abstract:: Implementing multicomponent diffusion in numerical combustion studies is computationally expensive due to the challenges involved in computing diffusion coefficients. As a result, mixture-averaged diffusion treatments or simpler methods are used to avoid these costs. However, the accuracy and appropriateness of the mixture-averaged diffusion model has not been verified for three-dimensional...
Resource Type:: Dissertation

Risk- and Reliability-Based Design Optimization in Offshore Renewable Energy Systems

Creator:: Clark, Caitlyn E.
Abstract:: Offshore wind and wave energy have the potential to be significant sources of future global electricity production, reduce carbon emissions, decrease dependence on energy importation, and stimulate economic growth in coastal and remote areas. Fixed-foundation and floating offshore wind and wave energy technologies are at different stages of development, but...
Resource Type:: Dissertation

Orb Web Vibrations: Modeling, Localization, and Measurement

Creator:: Otto, Andrew W.
Abstract:: The orb web is a multipurpose structure---serving as a home for its inhabitant spider, as a prey capture device, and as a physical extension of the spider’s sensing abilities. Biologists are particularly interested in the spider’s ability to locate prey trapped in its web by sensing the vibrations induced from...
Resource Type:: Dissertation

Topological Design Considering Uncertainty and Hyperelasticity

Creator:: Pham, Trung
Abstract:: Topology optimization (TO) is a mathematical method to find the optimal size, shape and connectivity of a domain under specified conditions, and has had many applications in engineering design. However, challenges remain in realizing TO as an effective design tool for many design situations. Uncertainty is ubiquitous in nature and...
Resource Type:: Dissertation

Usage of Digital Image Correlation in Single and Multiple Stereo Systems for Strain and Shape Measurement

Creator:: McKinley, Timothy A.
Abstract:: This dissertation details the application of digital image correlation (DIC) in novel methods for mechanical testing and shape characterization. The first usage manifested in the development of a novel composite test specimen that provided the ability to characterize the matrix compression energy release rate at initiation and subsequent crack propagation....
Resource Type:: Dissertation

Experimental Investigations of the Unsteady Aerodynamics of Oscillating Airfoils Operating in the Energy Harvesting Regime

Creator:: Siala, Firas F.
Abstract:: The rising global trend to reduce dependence on fossil fuels has provided significant motivation toward the development of alternative energy conversion methods and new technologies to improve their efficiency. Recently, oscillating energy harvesters have shown promise as highly efficient and scalable turbines, which can be implemented in areas where traditional...
Resource Type:: Dissertation

Smooth Trajectory Generation for Machine Tools and Industrial Robots

Creator:: Tajima, Shingo
Abstract:: This thesis presents accurate and time-optimal smooth reference trajectory generation techniques for manufacturing equipment such as high-speed machine tools (MT) and industrial robots (IR). Typical machining tool-paths for MTs and IRs are defined as a series of discrete linear moves. Although Point-to-Point (P2P) feed motion can be generated by interpolating...
Resource Type:: Dissertation

The Function-Human Error Design Method (FHEDM)

Creator:: Soria Zurita, Nicolás F.
Abstract:: This research presents a methodology to identify and analyze human-system interactions, and their potential failure modes using a functional decomposition approach during the early system design stage. The fundamental research contribution of this work is the development of a framework to identify associations between physical user-product interactions, generic human errors...
Resource Type:: Dissertation

Design for Clean Technology Adoption: Application of Discrete Choice Analysis and the Theory of Planned Behavior for Development Engineering

Creator:: Pakravan, Mohammad H.
Abstract:: Clean technologies can address multiple challenges associated with climate change, environmental protection, and human health. However, the impact desired by introduction of such technologies is achievable only if new options effectively replace inefficient, conventional practices. This ‘design for adoption’ requires understanding of user motivations, associated beliefs, context of use, and...
Resource Type:: Dissertation

Geometric Motion Planning for Inertial Systems

Creator:: Faraji, Hossein
Abstract:: In order to enable better visualization and understanding of the effect of the robot's geometry and inertia on the robot's trajectories, this dissertation proposes to use geometric mechanics to bridge the gap between the physical motion of a robot and its mathematical structure. The main focus of this research is...
Resource Type:: Dissertation

Incremental Forming of Polymers at Room Temperature

Creator:: Davar Panah, Mohammad Ali
Abstract:: Single Point Incremental Forming (SPIF) is a forming process in which a fully clamped sheet is formed by a hemispherical ended tool that moves along a predefined 3D toolpath. The sheet is formed in a series of local deformations to reach its desired shape. Double Sided Incremental Forming (DSIF) includes...
Resource Type:: Dissertation

Numerical Investigation of Unsteady Inertial and Turbulent Flows Through Porous Media: Pore-scale DNS, Flow Analyses and Upscaling

Creator:: He, Xiaoliang
Abstract:: Porous media are the materials containing void space or pores, where fluids and gases can pass through. Unsteady flows in porous media are encountered in many engineering applications and natural problems, such as CO₂ sequestration, high temperature nuclear reactor cooling, high efficiency combustion, chemical reactors, noise reduction on airplane trailing...
Resource Type:: Dissertation

Automated decomposition of complex parts for manufacturing with advanced joining processes

Creator:: Massoni, Brandon R.
Abstract:: Recent advancements in joining operations and additive manufacturing now allow complex metal parts to be built up from raw materials, as opposed to being machined down from solid blocks. This not only opens up the design space, but also allows for much more efficient manufacturing. By decomposing a complex part...
Resource Type:: Dissertation

Mechanical Behavior of Elastomer Polymer under Shear and Compression: Experimental Investigation Using Digital Image Correlation

Creator:: Raheem, Hassan M.
Abstract:: Due to their viscoelastic properties, polymers and hydrogels are widely used in many applications. In this study, the viscoelastic properties of elastomer polymers were investigated for a series of hydrogel, hydrogel composites and silicon materials. A primary application for hydrogels and hydrogel composites is as a replacement for the degenerated...
Resource Type:: Dissertation

Gathering information rich customer needs for inclusive product design

Creator:: Armstrong, Jessica
Abstract:: This work explores a framework for the gathering and analysis of information rich customer needs, with the goal of informing inclusive product design practice. The goal is to be able to provide information and experience to designers so that they can better understand the needs of exceptional users and include...
Resource Type:: Dissertation

Bio-Inspired Design of Vehicles that Operate in Complex Environments

Creator:: Jackson, Danielle M.
Abstract:: This dissertation focuses on defining underlying mechanisms to enable the bio-inspired design of aerodynamic and/or hydrodynamic vehicles that operate within complex environments. This dissertation introduces four overarching research gaps found in current bio-inspired design research and four corresponding approach questions that guide the framework of the presented research. This research...
Resource Type:: Dissertation

Autonomous Decision Making Facing Uncertainty, Risk, and Complexity

Creator:: Short, Ada-Rhodes
Abstract:: The creation of autonomous decision makers to handle potentially hazardous or logistically complicated tasks is desirable for the purpose of reducing human labor and exposure to risk, and for increasing the general performance of autonomous systems in a wide variety of environments. However, traditional autonomous decision makers perform poorly when...
Resource Type:: Dissertation

Rational Fuel Design for Low Temperature Internal Combustion Engines

Creator:: Daly, Shane R.
Abstract:: This work introduces a new methodology to design transportation fuels offering improved efficiency and reduced emissions, aimed to complement both traditional and emerging engine technologies. Many of these emerging technologies are centered around exploiting low temperature combustion (LTC) strategies that offer improved efficiency and reduced emissions. However, a standardized fuel...
Resource Type:: Dissertation

In-Situ Stereo Vision Metrology for Metal Powder Bed Fusion Additive Manufacturing

Creator:: Mosher, Daniel P.
Abstract:: Powder Bed Fusion (PBF) techniques are additive manufacturing (AM) technologies with paradigm-shifting potential for the production industry. However, before they can become viable production solutions for quality critical industries, issues with process consistency and repeatability need to be addressed. There is a need for in-situ sensing systems that characterize process...
Resource Type:: Dissertation

Non-Myopic Distributed Coordination and Planning for Robotic Teams

Creator:: Smith, Andrew
Abstract:: As robotic systems become increasingly prevalent in our lives (e.g., by harvesting food, assisting with disaster response and defense, and transporting persons and our goods around the world) there is a growing need to ensure that they can cooperate to achieve their intended goals. Robotic cooperation in the real-world is...
Resource Type:: Dissertation

Wave Energy Converter Array Optimization : Algorithm Development and Investigation of Layout Design Influences

Creator:: Sharp, Christopher J.
Abstract:: Realizing the vast amount of energy available in ocean waves, an industry has emerged that is progressing towards the deployment of grid–connected wave energy converters. Likely to be deployed in arrays, a challenge to the wave energy industry is maximizing the energy production of such arrays. We have been developing...
Resource Type:: Dissertation

Resilient Design for Complex Engineered Systems in the Early Design Phase

Creator:: Keshavarzi, Elham
Abstract:: There are many uncertainties that complex engineered systems will face throughout their lifecycles due to changes in internal and external conditions. It is desirable for complex engineered systems to be resilient against various uncertainties. The ability to overcome such uncertainties should be embedded into the system from the beginning. However,...
Resource Type:: Dissertation

Applying Multi-Objective Evaluation to Automated Assembly Planning in Early CAD Design Stage

Creator:: Huang, Weifeng
Abstract:: Successfully predicting an accurate estimated cost is important in the assembly planning process. When designing an assembly plan, an accurate estimation ensures that the proposed plan can be achieved within the predetermined budget. However, achieving an accurate prediction is a challenge since it requires professional judgment, which is dependent upon...
Resource Type:: Dissertation

An experimental investigation of radiative and total heat transfer around a horizontal tube immersed in a high temperature gas-solid fluidized bed

Creator:: Alavizadeh, Seyed Nasser
Abstract:: This study is primarily concerned with the measurement of the local radiative component of total heat transfer around a horizontal tube immersed in a large particle fluidized bed at elevated temperatures.Total heat transfer was also measured in order to assess the relative radiation contribution.The radiation measurement probe employs a silicon...
Resource Type:: Dissertation

Adaptive Multiagent Traffic Management for Autonomous Robotic Systems

Creator:: Rebhuhn, Carrie
Abstract:: There is growing commercial interest in the use of unmanned aerial vehicles (UAVs) in urban environments, specifically for package delivery applications. However, the size, complexity and sheer numbers of expected UAVs makes conventional air traffic management that relies on human air traffic controllers infeasible. To enable UAVs to safely and...
Resource Type:: Dissertation

Further Development of MPM and its Applications in Modeling Wood-Adhesive Bonds

Creator:: Hammerquist, Chad C.
Abstract:: This work is a culmination of a series of published works related to the use of the Material Point Method (MPM) in modeling wood adhesive bonds. The use of wood as construction material has the potential to play a small role in the solution to the current CO2 and climate...
Resource Type:: Dissertation

Effect of hydrous ethanol on crankcase oil dilution

Creator:: Khalifa, Gamaleldin A.
Abstract:: Adequate lubrication is of the utmost importance in internal combustion engines. Low temperature operation with low-proof alcohol may create some operational problems if alcohol and or water accumulates in the crankcase oil. Condensates of unburned alcohol and water may be blown into the crankcase oil with blow by gases. The...
Resource Type:: Dissertation

Computational Design for Metal Organic Responsive Frameworks (MORFs)

Creator:: Manion, Charles A.
Abstract:: Metal organic Frameworks (MOFs) that experience stimuli induced structural transformation could enable a whole new class of materials with remarkable properties. Photoactuating moieties in the structure could effect changes in the pore space or macroscale shape change enabling light driven gas separation and actuators. Here, we present a novel approach...
Resource Type:: Dissertation

Knowing your customers : ontological gathering and analysis techniques

Creator:: Nix, Anthony A.
Abstract:: This research presents a methodology to analyze customer needs and direct the gathering of customer needs that both span the need space and are independent. An ontological categorization, the fundamental research contribution of this work, is created to support both aims of the overall methodology. Providing designers with a customer...
Resource Type:: Dissertation

Automated Assembly Planning : From CAD Model to Virtual Assembly Process

Creator:: Rafibakhsh, Nima
Abstract:: Assembly planning is a crucial task for every manufacturing product. In general, assembly operations consume more than 30% of the total manufacturing time and cost. Therefore, any effort in optimizing assembly will have a significant impact on the economic success of manufacturing. Finding an optimal assembly plan by hand is...
Resource Type:: Dissertation

From Functional Modeling to Optimization : Risk and Safety in the Design Process for Large-Scale Systems

Creator:: McIntire, Matthew G.
Abstract:: In order to more effectively design large, complex systems, risk must be accounted for throughout the design process. A systematic way to account for risk is by using system model simulation. During the conceptual design phase, functional models can be drawn to help the engineer design their system's functional architecture....
Resource Type:: Dissertation

Crack Penetration and Deflection Behavior at Interfaces

Creator:: Alam, Mahabub
Abstract:: This study computationally and experimentally examines the mechanisms of crack penetration, deflection and the transition between penetration and deflection. The finite element analysis based computational modeling work used strength-and-energy based cohesive-zone approach to study the effect of dimensionless parameters (e.g., interfacial incident angle, fracture-length scale, and normalized toughness) on penetration/deflection...
Resource Type:: Dissertation

DNS study of Particle-bed-Turbulence Interactions in Oscillatory Flows

Creator:: Ghodke, Chaitanya Deepak
Abstract:: Turbulent flows over rough surfaces are encountered in many engineering and geophysical applications. Flows of this nature, due to their increasing technological interests, have been a subject of rigorous investigation in recent years. Of the particular interest to the oceanographic community is the study of turbulent oscillatory flow over rough...
Resource Type:: Dissertation

Characterizing Linkages Between the Climate, Cryosphere, and Impacts on Run-of-River Hydropower in Data-Sparse Mountain Environments

Creator:: Mosier, Thomas M.
Abstract:: In many regions of the world, a significant portion of the surface water originates in mountain headwaters where the timing and magnitude of streamflow is largely dictated by the seasonal storage of precipitation as snowpack and long-term storage as glaciers. Accumulation, persistence, and melt of snow and ice are functions...
Resource Type:: Dissertation

Understanding Designer Mental Models to Support Computer Directed Analogical Design

Creator:: Arlitt, Ryan M.
Abstract:: Analysis of alternative concepts has a significant impact on design project outcomes, and yet many design teams fail to consider a significantly broad range of conceptual solutions. Within the realm of conceptual design exists a technique called design by analogy (DBA) -- the practice of reapplying old solutions to new...
Resource Type:: Dissertation

Predicting Aerodynamic Loads on Highly Flexible Membrane Wings

Creator:: Carpenter, Trenton James
Abstract:: Through passive adaptation to incidental flow, flexible aerodynamic surfaces exploit effects of increased lift, delayed stall and disturbance rejection. Wings of birds, bats, and insects exhibit these passive effects, and at the same time through the use of structural state feedback sensed from the loads on the wing, active control...
Resource Type:: Dissertation

Single Phase and Flow Boiling Heat Transfer and Flow Characterization in Microscale Pin Fin Heat Sinks

Creator:: Rasouli, Erfan
Abstract:: The ever increasing requirements for heat dissipation in various thermal management applications such as computer chip cooling and high power electronics have necessitated the need for novel thermal management techniques. Thermal management using heat sinks with microscale features is amongst the prominent techniques developed over the past two decades. In...
Resource Type:: Dissertation

Multi-Objective Optimization in Multiagent Systems

Creator:: Yliniemi, Logan Michael
Abstract:: Cooperative multiagent systems are used as solution concepts in many application domains including air traffic control, satellite communications, and extra planetary exploration. As systems become more distributed and complex, we observe three phenomena. First, these systems cannot be accurately modeled, rendering traditional model based control methods inadequate. Second, system parameters...
Resource Type:: Dissertation

Vertical Axis Pendulum Wave Energy Converters : Investigating Control Strategies and the Deployment of a Scaled Generic Prototype

Creator:: Boren, Blake C.
Abstract:: Vertical Axis Pendulum Wave Energy Converters (VAPWECs) are thought to be both effective and robust at converting ocean wave energy into usable electricity. Seeking to build upon and investigate such potential, this work examines the merits of actively controlling a generic VAPWEC's pendulum for the purpose of increasing the converter's...
Resource Type:: Dissertation

From running birds to walking robots : optimization as a unifying framework for dynamic bipedal locomotion

Creator:: Hubicki, Christian M.
Abstract:: Bipedal locomotion is a complex phenomenon to understand and control, making it difficult for legged robots to achieve the speed, agility, efficiency, and robustness of their animal counterparts. This thesis argues for the use of numerical optimization to investigate and implement bipedal control as it applies to biology, dynamical models,...
Resource Type:: Dissertation

Dynamics and control for spring-mass legged robots

Creator:: Vejdani Noghreiyan, Hamid Reza
Abstract:: The objective of this study is to propose control strategies for legged robots to walk and run naturally like humans and animals. To achieve this goal, we use the spring-mass model for the legged robots to be able to create the same dynamics in the leg as humans and animals....
Resource Type:: Dissertation

The effects of ocean variability and breaking waves on wave energy converter reliability and survivability

Creator:: Brown, Adam
Abstract:: The reliability and survivability of a wave energy converter (WEC) is highly dependent on the variability and non-linearity of the ocean itself. Ocean variability occurs on many time scales. Climate variability occurs decade-to-decade, and year-to-year in the number and intensity of winter storms. Seasonal variation of wave height and period...
Resource Type:: Dissertation

The weldability of ductile iron

Creator:: Rice, William Harold, 1911-
Resource Type:: Dissertation

Tentative equilibrium diagram for the nickel-rich end of the nickel-zirconium system

Creator:: Armstrong, Asa William
Resource Type:: Dissertation

A framework for assessing and improving the resilience of complex engineered systems during the early design process

Creator:: Mehrpouyan, Hoda
Abstract:: As modern systems continue to increase in size and complexity, they pose significant safety and risk management challenges. System engineers and much of the government research efforts are focused on understanding the attributes and characteristics that emerge from the interactions of components and subsystems. As a result, the objective of...
Resource Type:: Dissertation

Design of robust infrastructure systems incorporating user behavior

Creator:: Piacenza, Joseph R., III
Abstract:: Infrastructure systems are a critical component supporting today's modern society. From power grids to traffic networks, we rely on these systems to perform as intended, despite the various sources of uncertainty present in their operation. Designing for system robustness can help mitigate the impact of failures caused by unexpected events....
Resource Type:: Dissertation

Design of a single lamina for a microchannel dialyzer with a focus on bubble removal

Creator:: Mohammadi, Mahshid
Abstract:: A microchannel-based hemodialyzer offers a novel approach to hemodialysis practice and holds many promises for improving dialysis treatment efficiency and quality of life for kidney patients. The hollow fiber hemodialyzer, a conventional dialysis device, has certain limitations including non-uniformity of the dialysate flow path which necessitates the use of a...
Resource Type:: Dissertation

Influence of environmental factors on human mental and motor performance in console operations

Creator:: Riggs, James Lear
Resource Type:: Dissertation

Purification of zirconium by solid state electrolysis and zone refining

Creator:: Claudson, Thomas Tucker
Resource Type:: Dissertation

Stagnation point heat transfer in a relaxing gas

Creator:: Wilson, Robert E.
Abstract:: Stagnation point heat transfer in a gas undergoing relaxation of its internal energy is examined by solution of the equations of motion using the two temperature approach of Wang Chang and Uhlenbeck. The results are presented in parametric form and show that relaxation effects produce an adiabatic wall temperature above...
Resource Type:: Dissertation

Multiagent learning for locomotion and coordination in tensegrity robotics

Creator:: Iscen, Atil
Abstract:: Tensegrity structures are composed of pure compressional elements that are connected via a network of pure tensional elements. The concept of tensegrity promises numerous advantages to the field of robotics. Tensegrity robots are, however, notoriously difficult to control due to their oscillatory nature and nonlinear interaction between the components. Multiagent...
Resource Type:: Dissertation

Normal modes in nonlinear nonsymmetrical systems with two degrees of freedom, and applications to air springs

Creator:: Moustafa, Mahmoud Abd-Elfattah
Abstract:: The study of nonlinear vibrations of systems having two degrees of freedom has met considerable attention during the past few years. Nonlinear symmetrical systems have received most of it. Normal mode motion of a system is defined as a periodic motion such that the masses of the system assume repeated...
Resource Type:: Dissertation

Theoretical and implementation improvements for difference evaluation functions

Creator:: Colby, Mitchell Kataichi
Abstract:: Multiagent learning with cooperative coevolutionary algorithms is a critical area of research, and is relevant to many real-world applications including air traffic control, distributed sensor network control, and game-theoretic applications such as border patrol. A key difficulty in multiagent learning is the credit assignment problem, where the impact of each...
Resource Type:: Dissertation

Effects of selected minor alloying additions on the structure deformation characteristics of beryllium

Creator:: Dooley, George Joseph, III
Abstract:: Solid solution alloying was employed in an attempt to produce some relatively ductile form of beryllium. If the c/a ratio could be significantly altered, it was felt new or different slip systems could be activated. The following elements were selected on the basis of atomic size, melting point, crystal structure...
Resource Type:: Dissertation

Correlations between crystal orientation, deformation texture, and indentation anisotropy in tungsten and molybdenum single crystals

Creator:: Sandwith, Colin John
Resource Type:: Dissertation

An explicit finite-difference solution for natural convection in air in rectangular enclosures

Creator:: Pagnani, Bruno Richard
Resource Type:: Dissertation

A model of ciliary streaming in the respiratory system

Creator:: Chambers, Alan B.
Abstract:: The respiratory tract is lined with a mucous blanket which is motivated by a ciliated epithelium. This blanket includes a lower serous layer of fluid through which the cilia beat and an upper viscid layer into which particulates from the inhaled air are deposited. The movement of the mucous blanket...
Resource Type:: Dissertation

The phase diagram of zirconium and chromium with special reference to the transformation in the intermetalic compound ZrCr₂

Creator:: Shen, Yuan-shou
Abstract:: The zirconium-chromium phase diagram was investigated in the region between 40% and 85% chromium. The ZrCr₂ intermetallic compound which has been the source of some controversy was especially considered. It was found that ZrCr₂ transforms from the low temperature C-15 (MgCu₂, FCC) structure to the high temperature C-14 (MgZn₂, HCP)...
Resource Type:: Dissertation

An experimental investigation of combustion products through a flat, laminar, pre-mixed hydrocarbon-air flame

Creator:: Brenchley, David Lee
Abstract:: Flat, laminar, premixed hydrocarbon-air flames were stabilized on a porous-plate burner. In addition to temperature profiles, concentration profiles were measured for methane, ethane, ethylene, propane, acetylene, propylene, carbon monoxide, carbon dioxide and oxides of nitrogen. Dead space thickness, luminous flame zone thickness and hydrocarbon disappearance point responses were also monitored....
Resource Type:: Dissertation

A numerical solution for heat transfer to non-Newtonian fluids with temperature-dependent viscosity for arbitrary conditions of heat flux and surface temperature

Creator:: Cochrane, G. F. (Glenn Frank)
Resource Type:: Dissertation

An experimental investigation of transition pool boiling

Creator:: Aoki, Tadao
Abstract:: The heat-transfer phenomena studied in this work were associated with pool boiling from a flat horizontal surface facing upward with the bulk liquid at its saturation temperature. The analysis of boiling sound and the investigation of the transition boiling mechanism constituted the essence of the present study. The distinctively large...
Resource Type:: Dissertation

Initial performance of rigid, porous sheets of sintered-polyethylene powder for filtering airborne sander dust

Creator:: Anderson, Charles Michael
Resource Type:: Dissertation

Analysis of heat pump and steam bleed-off systems linked with thermal-electric power plants to supply low-grade heating and cooling

Creator:: Ileri, Arif
Abstract:: This thesis analyzes two systems that can meet low-grade heating and/or cooling demands by operating in conjunction with thermal-electric power plants. At the application site, one of the systems, HPS, has water-to-air heat pumps that are connected to the supply and return lines of a plant-to-user loop. During heating, the...
Resource Type:: Dissertation

An investigation of the effects of radial acceleration on a fluidized bed used for filtration of air-borne particulate of submicron size

Creator:: Junge, David C.
Resource Type:: Dissertation

Airborne sampling of particles emitted to the atmosphere from Kraft paper mill processes and their characterization by electron microscopy

Creator:: Augustine, Frank Edward
Abstract:: A high volume sampling system, employing Nuclepore filters and designed for sampling particulate in the plumes from industrial sources using a light aircraft, is described. The effluent of kraft paper mills was sampled using this system and then analyzed by electron microscopy. Size distributions of particles were obtained at several...
Resource Type:: Dissertation

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