Mechanical Engineering Commons^™

Thermoelectric Material Property Measurement For Flexible Films, Courtney Hollar

Boise State University Theses and Dissertations

The market for wearable electronics and implantable medical devices continues to grow. Within the next several years, the wearable electronic and implantable medical devices market will reach $31.2 billion and $73.9 billion, respectively. Currently, the most commonly used power source is the rigid lithium ion battery. In order to further optimize the devices, flexible autonomous power sources, such as thermoelectric generators, can replace traditional battery systems.

Flexible thermoelectric films were created using a wet deposition approach and synthesized into ink suitable for either spin coating or screen printing. This study focuses on Seebeck coefficient, electrical conductivity, and thermal conductivity measurements. …

Enhanced Thermal Conductance Of Polymer Composites Through Embedding Aligned Carbon Nanofibers, David S. Wood, Dale K. Hensley, Nicholas A. Roberts

Mechanical and Aerospace Engineering Faculty Publications

The focus of this work is to find a more efficient method of enhancing the thermal conduc-tance of polymer thin films. This work compares polymer thin films embedded with randomly oriented carbon nanotubes to those with vertically aligned carbon nanofibers. Thin films embedded with carbon nanofibers demonstrated a similar thermal conductance between 40–60 µm and a higher thermal con-ductance between 25–40 µm than films embedded with carbon nanotubes with similar volume fractions even though carbon nanotubes have a higher thermal conductivity than carbon nanofibers.

Nanomaterials For Solar Distillation Technology, Jack Warren Stoddard Cheney

UNLV Theses, Dissertations, Professional Papers, and Capstones

Water is the most important resource for mankind. Yet, 97% of the earth’s surface water is seawater in the oceans and only 3% is fresh water in ground water. Therefore, different kinds of water desalination and treatment technologies have been developed, and water distillation is a basic process of evaporating water in order to leave behind impurities such as minerals, pollutants, and other contaminants. Although distillation is known as an effective water treatment process that removes many kinds of bacteria and inorganic chemicals and heavy metals, a large amount of conventional energy and non-renewable resources are consumed for this process. …

The Validation And Verification Of Les Modeling Using Kiva, David Fyda

UNLV Theses, Dissertations, Professional Papers, and Capstones

In recent years, the use of large-eddy simulation (LES) has grown into new research methods. LES is preferred when compared to Reynold’s Averaged Navier Stokes (RANS), which separates velocity components into steady and fluctuating components. While RANS is relatively easy to implement, it does not fully resolve the range of turbulence eddies and has limitations that make it inaccurate in many practical circumstances. Direct numerical simulation, DNS, fully resolves all turbulent eddies to the smallest grid scale, but requires an extremely fine grid. This makes it computationally impractical to use as the computational power required to solve even the simplest …

Visualization Of Dropwise Condensation On Vertical Plate And Horizontal Tube Geometry, Blake Naccarato

UNLV Theses, Dissertations, Professional Papers, and Capstones

A droplet detection method has been developed to measure the distribution of droplet sizes on a flat plate under dropwise condensation. Dropwise condensation heat transfer may be modeled by combining an expression for the single droplet heat transfer rate with the droplet size distribution. The ability to measure this distribution is integral to the validation of such models. An example study is undertaken in which heat flux is obtained for a given surface treatment by implementing such a model and measuring the droplet size distribution. These results are compared with the heat flux measured by internal coolant temperature monitoring for …

Comparing Efficacy Of Different Dynamic Models For Control Of Underdamped, Antagonistic, Pneumatically Actuated Soft Robots, Morgan Thomas Gillespie

Theses and Dissertations

Research in soft robot hardware has led to the development of platforms that allow for safer performance when working in uncertain or dynamic environments. The potential of these platforms is limited by the lack of proper dynamic models to describe or controllers to operate them. A common difficulty associated with these soft robots is a representation for torque, the common electromechanical relation seen in motors does not apply. In this thesis, several different torque models are presented and used to construct linear state-space models. The control limitations on soft robots are induced by natural compliance inherent to the hardware. This …

Design, Testing And Evaluation Of Robotic Mechanisms And Systems For Environmental Monitoring And Interaction, James K. Higgins

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Unmanned Aerial Vehicles (UAVs) have significantly lowered the cost of remote aerial data collection. The next generation of UAVs, however, will transform the way that scientists and practitioners interact with the environment. In this thesis, we address the challenges of flying low over water to collect water samples and temperature data. We also develop a system that allows UAVs to ignite prescribed fires. Specifically, this thesis contributes a new peristaltic pump designed for use on a UAV for collecting water samples from up to 3m depth and capable of pumping over 6m above the water. Next, temperature sensors and their …

Position And Stiffness Control Of Inflatable Robotic Links Using Rotary Pneumatic Actuation, Charles Mansel Best

Theses and Dissertations

Inflatable robots with pneumatic actuation are naturally lightweight and compliant. Both of these characteristics make a robot of this type better suited for human environments where unintentional impacts will occur. The dynamics of an inflatable robot are complex and dynamic models that explicitly allow variable stiffness control have not been well developed. In this thesis, a dynamic model was developed for an antagonistic, pneumatically actuated joint with inflatable links.The antagonistic nature of the joint allows for the control of two states, primarily joint position and stiffness. First a model was developed to describe the position states. The model was used …

Robust Bi-Directional Continuous Electrowetting Based On Metal-Semiconductor (M-S) Diodes, Qi Ni, Daniel E. Capecci, Millicent Schlafly, Nathan B. Crane

Faculty Publications

We demonstrate bi-directional continuous electrowetting by embedding metal-semiconductor diodes in the electrowetting substrate. Unlike conventional electrowetting on dielectric (EWOD), bi-directional continuous electrowetting uses a single electrode pair to actuate a droplet through long distances. As long as the voltage potential is maintained between two end electrodes, the droplet moves toward the electrode with the higher potential. However, previously reported material systems had limited success in repeated actuation. In this work, diodes based on Schottky barriers were fabricated by forming metal-semiconductor junctions between titanium and high resistivity n-type silicon. The performance enhancements were evaluated using current-voltage measurements of interface pairs. When …

Florida Rural Small Business Energy Assistance Collaborative Cumulative Report Ending July 31, 2016, Florida Solar Energy Center, Janet Mcilvaine

FSEC Energy Research Center®

The U.S. Department of Agriculture's (USDA) Rural Development initiative reaches out to communities across America with many programs (http://www.rd.usda.gov/programs-services/all-programs). USDA's Rural Energy for America Program (REAP) offers grants and loan guarantees for energy efficiency improvements and renewable energy systems to agriculture operations and qualifying rural small businesses. USDA has awarded the University of Central Florida a grant to provide a limited number of subsidized Energy Audits to eligible businesses in Florida in support of USDA Rural Development (USDA-RD) Grant and Loan programs for rural small businesses. The ultimate goal of the energy audits is to increase participation in …

Cost Effectiveness Of Energy Efficiency And On-Site Photovoltaic Power For 2015 Iecc Energy Rating Index (Eri) Compliance (Draft), Florida Solar Energy Center, Philip W. Fairey

FSEC Energy Research Center®

EnergyGauge® USA v.5.1 is used to simulate the energy use of one-story, three-bedroom, 2000 ft² , single-family, frame homes in sixteen representative U.S. climates comprising all eight IECC climate zones. The energy use of the Section R406.2 minimum efficiency home (the Baseline Home) is compared against the energy use of homes complying with the prescriptive requirements of Section R402 of the 2015 IECC and against homes complying with the Section R406 Energy Rating Index (ERI) Compliance Alternative. The improvement cost and energy savings of the improved homes relative to the Baseline Home are then used to determine the cost …

Generalizations On Active-Passive Dynamic Consensus Filters, J. Daniel Peterson, Tansel Yucelen, Eduardo Pasiliao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Active-passive dynamic consensus filters consist of agents subject to local observations of a process of interest (active agents) and agents without any observations (passive agents). In this paper, we introduce a new class of active-passive dynamic consensus filters using results from graph theory and systems science. Specifically, the proposed filters only require agents to exchange their current state information with neighbors in a simple and isotropic manner to reduce the overall information exchange cost of the network. In addition, we allow the roles of active and passive agents to be time-varying for making these filters suitable for a wide range …

Multiplex Information Networks For Spatially Evolving Multiagent Formations, Dung Tran, Tansel Yucelen, Eduardo Pasiliao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, we show how information exchange rules represented by a network having multiple layers (multiplex information networks) can be designed for enabling spatially evolving multiagent formations. Specifically, we consider the formation tracking problem and introduce a novel distributed control architecture. The proposed approach allows capable agents to spatially alter density and orientation of the resulting formation while tracking a dynamic, non-stationary target without requiring global information exchange ability. A numerical example is provided to illustrate the efficacy of the proposed distributed control architecture.

Adaptive Control Architectures For Mitigating Sensor Attacks In Cyber-Physical Systems, Tansel Yucelen, Wassim M. Haddad, Eric M. Feron

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The accuracy of sensor measurements is critical to the design of high-performance control systems since sensor uncertainties can significantly deteriorate achievable closed-loop dynamical system performance. Sensor uncertainty can arise due to low sensor quality, sensor failure, or detrimental environmental conditions. For example, relatively cheap sensor suites are used for low-cost, small-scale unmanned vehicle applications that can result in inaccurate sensor measurements. Alternatively, sensor measurements can also be corrupted by malicious attacks if dynamical systems are controlled through large-scale, multilayered communication networks as is the case in cyber-physical systems. This paper presents several adaptive control architectures for stabilization of linear dynamical …

Mitigating The Effects Of Sensor Uncertainties In Networked Multiagent Systems, Ehsan Arabi, Tansel Yucelen, Wassim M. Haddad

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Networked multiagent systems consist of interacting agents that locally exchange information, energy, or matter. Since they do not in general have a centralized entity to monitor the activity of each agent, resilient distributed control system design for networked multiagent systems is essential in providing high system performance, reliability, and operation in the presence of system uncertainties. An important class of such system uncertainties that can significantly deteriorate the achievable closed-loop system performance is sensor uncertainties, which can arise due to low sensor quality, sensor failure, sensor bias, or detrimental environmental conditions. This paper presents a novel distributed adaptive control architecture …

A New Model Reference Control Architecture: Stability, Performance, And Robustness, Gerardo De La Torre, Tansel Yucelen, Eric N. Johnson

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, we develop a new model reference control architecture to effectively suppress system uncertainties and achieve a guaranteed transient and steady-state system performance. Unlike traditional robust control frameworks, only a parameterization of the system uncertainty given by unknown weights with known conservative bounds is needed to stabilize uncertain dynamical systems with predictable system performance. In addition, the proposed architecture's performance is not dependent on the level of conservatism of the bounds of system uncertainty. Following the same train of thought as adaptive controllers that modify a given reference system to improve system performance, the proposed method is inspired …

Guided Wave Based Crack Detection In The Rivet Hole Using Global Analytical With Local Fem Approach, Bhuiyan Yeasin Md, Yanfeng Shen, Victor Giurgiutiu

Faculty Publications

In this article, ultrasonic guided wave propagation and interaction with the rivet hole cracks has been formulated using closed-form analytical solution while the local damage interaction, scattering, and mode conversion have been obtained from finite element analysis. The rivet hole cracks (damage) in the plate structure gives rise to the non-axisymmetric scattering of Lamb wave, as well as shear horizontal (SH) wave, although the incident Lamb wave source (primary source) is axisymmetric. The damage in the plate acts as a non-axisymmetric secondary source of Lamb wave and SH wave. The scattering of Lamb and SH waves are captured using wave …

Enthalpy-Based System-Model For Pumped Two-Phase Cooling Systems, Leitao Chen, Fanghao Yang, Pritish R. Parida, Mark Schultz, Timothy Chainer

Publications

The development of embedded chip cooling for 2D and 3D integrated circuits using pumped dielectric refrigerant has gained recent attention due to the ability to manage high heat densities and compatibility with electronics. Recent studies have focused on in-situ thermal and hydrodynamic phenomena (e.g. boiling and bubble dynamics) of two-phase flow boiling at micro-scales. In this paper we focus on the two-phase cooling system design including the cooling capability, size and coefficient of performance (COP). In implementing a two-phase cooling, a system-level computational model for two-phase cooling systems becomes necessary. Therefore, a computationally manageable and accurate one dimensional (1D) system …

Effects Of Emf Emissions From Undersea Electric Cables On Coral Reef Fishes, Robert F. Jermain

HCNSO Student Theses and Dissertations

The objective of this project was to determine if the electromagnetic field (EMF) emissions from undersea power cables impacted the local and transient marine life, with an emphasis on reef fishes. The work was done at South Florida Ocean Measurement Facility of Naval Surface Warfare Center, Carderock Division, Broward County, Florida. This facility functions as the hub for a range of active undersea detection and data transmission cables. It has multiple active submarine power cables that extend several miles offshore and which can deliver power and enable data transmission to and from a range of acoustic and EMF sensors. The …

Thermal Modeling And Nanoindentation Of Shape Memory Alloy Thin Films, Mehmet Mete Ozturk

Theses and Dissertations

Metal alloys which go through a hysteric transformation due to external stimuli such as thermal and/or mechanical fields are called shape memory alloys (SMA). Thin films of SMAs have many remarkable features and have been used in the fabrication of microactuators. One potential application is a SMA thin film based information storage device. In all these applications, the existence of the strong thermomechanical coupling inherent in the phase transformation is seen. Due to coupling, knowledge of not only the mechanical field but also the thermal field is essential. The objective of this work is to study the thermal behavior of …

Insights Into Twinning In Mg Az31: A Combined Ebsd And Machine Learning Study, David T. Fullwood, Andrew Orme, Isaac Chelladurai, Travis Michael Rampton, Ali Khosravani, Michael Miles, Raj K. Mishra

Faculty Publications

To explore the driving forces behind deformation twinning in Mg AZ31, a machine learning framework is utilized to mine data obtained from electron backscatter diffraction (EBSD) scans in order to extract correlations in physical characteristics that cause twinning. The results are intended to inform physics-based models of twin nucleation and growth. A decision tree learning environment is selected to capture the relationships between microstructure and twin formation; this type of model effectively highlights the more influential characteristics of the local microstructure. Trees are assembled to analyze both twin nucleation in a given grain, and twin propagation across grain boundaries. Each …

So, You Want An X-Y Table?, Michael J. Bennett

UConn Library Presentations

Presentation on the University of Connecticut Libraries' automated X-Y table for digital capture of oversized archival maps, plans, art, illustrations, etc. Custom table designed by Michael Ulsaker (Ulsaker Studio, Glastonbury, CT), and Michael J. Bennett (University of Connecticut Library Digital Production Studio). System integration and assembly by Michael Ulsaker. Automation engineering by WEI Inc., Old Saybrook, CT using Yamaha Robotics and Allen Bradley PLC.

Roots Air Management System With Integrated Expander, Dale Stretch, Brad Wright, Matt Fortini, Neal Fink, Bassem Ramadan, William Eybergen

Mechanical Engineering Presentations And Conference Materials

PEM fuel cells remain an emerging technology in the vehicle market with several cost and reliability challenges that must be overcome in order to increase market penetration and acceptance. The DOE has identified the lack of a cost effective, reliable, and efficient air supply system that meets the operational requirements of a pressurized PEM 80kW fuel cell as one of the major technological barriers that must be overcome. This project leveraged Roots positive displacement development advancements and demonstrated an efficient and low cost fuel cell air management system. Eaton built upon its P-Series Roots positive displacement design and shifted the …

Wake Character In The Wind Turbine Array: (Dis-)Organization, Spatial And Dynamic Evolution And Low-Dimensional Modeling, Nicholas Michael Hamilton

Dissertations and Theses

To maximize the effectiveness of the rapidly increasing capacity of installed wind energy resources, new models must be developed that are capable of more nuanced control of each wind turbine so that each device is more responsive to inflow events. Models used to plan wind turbine arrays and control behavior of devices within the farm currently make questionable estimates of the incoming atmospheric flow and update turbine configurations infrequently. As a result, wind turbines often operate at diminished capacities, especially in arrays where wind turbine wakes interact and inflow conditions are far from ideal. New turbine control and wake prediction …

Modeling Atypical Building Use With Commercially Available Building Simulation Software, Sarah E. Schanck

Theses and Dissertations

National Guard armories are audited to provide recommendations for future energy reduction measures. The annual energy consumption of a New Jersey National Guard Armories cannot be modeled directly with commercially available building simulation software, due to discrepancies between the modeling capabilities of the software and the reality of the armory. A building simulation software, eQUEST, was chosen for use in this project. Discrepancies between eQUEST inputs and reality were identified and correction factors developed to minimize the effect of each discrepancy on predicted energy consumption, with the end goal of accuracy between predicted and actual energy consumption. In addition, an …

Improving Automated Global Detection Of Volcanic So2 Plumes Using The Ozone Monitoring Instrument (Omi), Verity Flower, Thomas Oommen, Simon Carn

Michigan Tech Publications, Part 1

Volcanic eruptions pose an ever-present threat to human populations around the globe, but many active volcanoes remain poorly monitored. In regions where ground-based monitoring is present the effects of volcanic eruptions can be moderated through observational alerts to both local populations and service providers such as air traffic control. However, in regions where volcano monitoring is limited satellite-based remote sensing provides a global data source that can be utilized to provide near real time identification of volcanic activity. This paper details the development of an automated volcanic plume detection method utilizing daily, global observations of sulphur dioxide (SO2) by the …

Design For Manufacturability: Off-Road Toyota Bumper, Drew Donlon

Industrial and Manufacturing Engineering

The purpose of this project is to design a new off-road bumper that is improved from the stock form of a 1996-2002 Toyota 4Runner and a 1996-2004 Toyota Tacoma. The current state of the component is too weak to endure to off-road endeavors, and a kit bumper market is virtually untapped for these vehicles. The objectives of this project were met by redesigning the stock front bumper, conducting a finite element analysis on the model to test for strength, prototyping the bumper with CNC cut cardboard, and conducting a full cost analysis including the costs for waterjet and laser cutting …

Go With The Flow –Thermoelectric Energy, Shawn Bell

Middle School Lesson Plans

In this unit, students will learn how thermal energy be transferred and transformed. They will carry out investigations to gather evidence to support an explanation about direct conversion of heat into electrical energy. They will develop a model that shows the components of the system and changes in the system being investigated, and they will use evidence from the investigation to construct an explanation for how the energy flows.

Analytical Modeling Of A Novel Microdisk Resonator For Liquid-Phase Sensing: An All-Shear Interaction Device (Asid), Mohamad Sadegh Sotoudegan

Dissertations (1934 -)

Extensive research on micro/nanomechanical resonators has been performed recently due to their potential to serve as ultra-sensitive devices in chemical/biosensing. These applications often necessitate liquid-phase sensing, introducing significant fluid-induced inertia and energy dissipation that reduces the resonator’s performance. To minimize the detrimental fluid effects on such devices, a novel microdisk resonator supported by two tangentially-oriented, axially-driven “legs” is investigated analytically and effects of the system parameters on the resonator/sensor performance are explored. Since the device surface vibrates primarily parallel to the fluid-structure interface, it is referred to here as an “all-shear interaction device,” or ASID. Analytical modeling of the ASID …

Investigation Of Small-Scale Thermal Recovery And Storage Systems, Suvhashis Thapa

Doctoral Dissertations

An approach to recover and store waste heat is presented in this dissertation. The waste heat is the energy that is rejected to the environment without being put to practical use and it is a result of both equipment inefficiency and thermodynamic limitation on the equipment and the process. In a typical Otto cycle, for instance, out of the total energy consumed by the system, only one-third of the energy is converted into useful work and the rest is discharged in the environment as waste heat [1]. For a spark ignition, a 1.4 liters internal combustion engine with the thermal …