Mechanical Engineering Commons^™

Data Consistency And Conflict Avoidance In A Multi-User Cax Environment, Robert Aaron Moncur

Theses and Dissertations

This research presents a new method to preserve data consistency in a multi-user CAx environment. The new method includes three types of constraints which work by constraining and controlling both features and users across an entire multi-user CAx platform. The first type of constraint includes locking or reserving features to enable only one user at a time to edit a given feature. The second type of constraint, collaborative feature constraints, allows flexible constraining of each individual feature in a model, and the data that defines it. The third type of constraint, collaborative user constraints, allows the constraining of user permissions …

High-Throughput Rear-Surface Drilling Of Microchannels In Glass Based On Electron Dynamics Control Using Femtosecond Pulse Trains, Lan Jiang, Pengjun Liu, Xueliang Yan, Ni Leng, Chuancai Xu, Hai Xiao, Yongfeng Lu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This study proposes a rear-surface ablation enhancement approach to fabricate high-aspect-ratio microchannels by temporally shaping femtosecond laser pulse trains. in the case study of K9 glass, enhancements of up to a 56 times higher material removal rate and a three times greater maximum drilling depth are obtained by the proposed method, as compared with conventional femtosecond laser drilling at the same processing parameters. the improvements are due to the changes of photon-electron interactions by shaping femtosecond pulse train, which can effectively adjust the photon absorption and localized transient material properties by changing electron dynamics such as free electron densities. © …

Performance Comparisons Of Personal And Professional-Grade 3d Printers, Alfonso Fernandez, Ryan Wicker, Francisco R. Medina, David Espalin

COURI Symposium Abstracts, Summer 2012

The recent emergence of personal 3D printers (i.e., systems that cost $5,000 or less) has engaged a new class of users including hobbyists, tinkerers, entrepreneurs, and do-it-yourselfers. Over 20,000 personal 3D printers were sold in 2011, and thus there is a need for users to understand the cost and performance of personal 3D printers as compared to low-cost professional-grade machines (i.e., systems that cost between $5,000 and $20,000). The cost, process time, material usage, and dimensional accuracy was assessed for select personal 3D printers and low-cost professional-grade systems. The study showed that the laminated object manufacturing (LOM) printer generated 80% …

A Comparative Study Of Strength And Stiffness Of Thin-Walled Specimens Fabricated By Fdm And 3d Printing Technologies, Miranda Rodrigo

Theses and Dissertations

Rapid Prototyped part failure constitutes a major issue for both RP providers and customers. When parts fail the reputation of the vendor is heavily deteriorated, customer dissatisfaction increase and replacement of the broken parts is often necessary to avoid the loss of future business. Product design teams often run into situations where Rapid Prototyped parts are not able to withstand shipping and handling and delivered broken or while demonstrating and examining the parts. When done in the face of customers this builds a perception of poor quality and lack of aptitude on the design group as well as the RP …

Sic-Cnt Multifunctional Nanocomposites For High Temperature Structural, Thermoelectric And Sensing Applications, Salvador Sandoval, Luz I. Bugarin, Luz I, Arifur Chowdhury, Luisa A. Cabrera, Mujibur R. Khan

COURI Symposium Abstracts, Summer 2012

The purpose of this project is to study the thermal-electrical and mechanical properties of the Nanojunctions between Single-Wall Carbon Nanotubes (SWCNT) and Silicon Carbide (SiC). The mixture was done by spreading the nanoparticles in a solution of ethanol and SiC, then sintered to a solid sample of 10 mm x 10 mm x 35 mm, which was attached with Alumel (Ni-Al) wire using silver epoxy to form a circuit for recording during fracture testing. The carbon nanotubes used were approximately 60% semiconducting and 40% metallic. The themal-electrical effect changed when SWCNTs (at 2, and 5 wt%) were infused into SiC. …

Nanowire-Graphene Hybrids For Li-Ion Insertion, Philip A. Morton, Mohammad Arif I. Shuvo, Yirong Lin

COURI Symposium Abstracts, Summer 2012

Lithium ion batteries are one of the most popular energy storage devices due to its high energy density. However, their performance is hindered by the limited surface area of the anode. This research focuses on the use of graphene nanowire hybrids and their performance as anode material. These hybrid structures have a greater surface area then graphite, the most common anode material. Greater surface area will enhance lithium ion insertion, and thus improve battery performance. The graphene oxide (GO) will be synthesized using the Hummer’s plus method. The GO will be sonicated and reduced in an argon furnace to form …

Research And Development Of An Extremely Affordable Prosthetic Knee, Victor H. Duenas, Noe Vargas-Hernandez

COURI Symposium Abstracts, Summer 2012

The objective of this research and development work is to apply the design process in a prosthetic knee mechanism. The importance of human knee is founded in the provided mobility, body positioning and support of the body weight. But for amputees, limitations for everyday tasks imply a real challenge. The project scope a cycle involving the social need, the development and the supply of the solution layout. The motivation is to improve life quality through voluntary and independent human movement by providing a low cost knee design.

The design process requires the conceptual, embodiment, detail and evaluation phases to complete …

Research And Development Of An Expert System In Idea Generation Methods To Aid In The Engineering Design Process, Rodrigo Enriquez, Noe Vargas-Hernandez

COURI Symposium Abstracts, Summer 2012

The objective of this research is to develop an Expert System (i.e. software) to aid designers in selecting appropriate idea generation methods for their specific design situation. This expert system would help designers generate creative ideas more frequently, and hence better designs and better products for society. The first step is to understand the creative design process in detail; this involves the engineering design process, cognitive processes, and other related elements. This understanding is represented initially as a conceptual model. Following an Artificial Intelligence (AI) approach, this model is then developed into a Logical model that defines entities, attributes, and …

Order-Disorder Transition Of Aragonite Nanoparticles In Nacre, Zaiwang Huang, Xiaodong Li

Faculty Publications

Understanding nacre’s bottom-up biomineralization mechanism, particularly, how individual aragonite platelets are formed, has long remained elusive due to its crystallographic peculiarity and structural complexity. Here we report that crystallographic order-disorder transition can be triggered within individual aragonite platelets in pristine nacre by means of heat treatment and/or inelastic deformation, offering a unique opportunity to discriminate mysterious aragonite nanoparticles in transmission electron microscopy. Our findings unambiguously uncover why aragonite nanoparticles in pristine nacre have long been inaccessible under TEM observation, which is attributed to the monocrystal-polycrystal duality of the aragonite platelet. The underlying physical mechanism for why an individual aragonite platelet …

Toward A Gpu-Accelerated Immersed Boundary Method For Wind Forecasting Over Complex Terrain, Rey Deleon, Kyle Felzien, Inanc Senocak

Mechanical and Biomedical Engineering Faculty Publications and Presentations

A short-term wind power forecasting capability can be a valuable tool in the renewable energy industry to address load-balancing issues that arise from intermittent wind fields. Although numerical weather prediction models have been used to forecast winds, their applicability to micro-scale atmospheric boundary layer flows and ability to predict wind speeds at turbine hub height with a desired accuracy is not clear. To address this issue, we develop a multi-GPU parallel flow solver to forecast winds over complex terrain at the micro-scale, where computational domain size can range from meters to several kilometers. In the solver, we adopt the immersed …

Analytical Thermal Model Of Friction Stir Welding With Spatially Distributed Heat Source, Gordon Scott Reese

Theses and Dissertations

Friction stir welding (FSW) has been studied extensively for the past two decades. Thermal modeling has been of particular interest, as the quality of the weld is dependent upon the temperature history of the work piece during the process. Since direct temperature measurements of the welded zone are not possible, an analytical model was developed to predict the temperature in this area. This model requires parameters that cannot be easily experimentally determined, so a best fit for these parameters was acquired via regression analysis by comparing the model to experimental data acquired outside of the weld zone. The model was …

Measurement And Analysis Of Gas Composition In A Staged And Unstaged Oxy-Fired Pulverized Coal Reactor With Warm Flue Gas Recycle, Skyler Charles Chamberlain

Theses and Dissertations

Nearly half of the electrical power produced in the United States is generated with coal. Coal power is inexpensive and reliable, but coal combustion releases harmful pollutants including NOx and SOx into the atmosphere if not controlled. CO2, a greenhouse gas, is also released during coal combustion and may contribute to global warming. A promising technology enabling carbon capture is oxy-coal combustion. During oxy-combustion, coal is burned in an atmosphere of O2 and recycled flue gas to eliminate nitrogen which makes up the majority of air-combustion flue gas. Oxy-combustion flue gas is mainly composed of CO2 and H2O. H2O can …

Modeling Of Complex Pentahedron Solar Still Covers To Optimize Distillate, Jeremy D. Lefevre

Theses and Dissertations

This work shows the results of modeling and optimizing pentahedron-shaped covers for application on a passive solar still. While modeling under the assumption of clear weather in Provo, Utah, United States of America, it was found that two main geometries resulted: A single slope still with fully vertical back and sidewalls and a south face tilted at 37.1°, absorbing a total of 8.98 megajoules of direct solar radiation. A half-pyramid shaped cover with vertical backwall, sidewalls tilted in at 60.6°, and a south face tilted in at 41.5°, absorbing 9.34 megajoules of direct solar radiation.With improved covers, solar radiation absorbed …

Three Dimensional Characterization Of Vocal Fold Fluid Structure Interactions, Joseph R. Nielson

Theses and Dissertations

Voice quality is strongly linked to quality of life; those who suffer from voice disorders are adversely affected in their social, family, and professional relationships. An effort has been made to more fully understand the physics behind how the voice is created, specifically the fluid structure interactions that occur during vocal fold vibration. Many techniques have been developed and implemented to study both the motion of the vocal folds and the airflow that creates the motion. Until recently these techniques have sought to understand a highly three-dimensional phenomenon with 1D or 2D perspectives.This research focuses on the development and implementation …

Investigation Of Internal Wave Spectra Due To Observed Interactions, Benjamin Lee Hillyard

Theses and Dissertations

Observational data are analyzed and decomposed to reveal internal ocean waves and their interactions with one another. Particularly, the interaction of small-scale internal waves with a large inertia wave packet is examined. Using the governing internal wave equations, an analysis is made of the energy propagation of a small scale internal wave with a large-scale inertia wave. With that, an assessment is made of the frequency of occurrence of various encounter types. Next, the possibility of energy transfer during an interaction is explored. The relative energy of the small wave before interacting with the large-scale inertia wave is calculated and …

Investigation Of A Planetary Differential For Use As A Continuously Variable Transmission, Austin B. Randall

Theses and Dissertations

With gas prices on the rise, the demand for high-mileage and low pollution vehicles has taken on an unprecedented role in our society. The production and implementation of electric and hybrid-electric vehicles has recently been a large focus of all major automobile manufacturers. Although these new vehicles have begun to solve much of the expensive fuel consumption and air pollution problems that our economy faces, the initial cost of these vehicles has proven to still be too expensive to capture a significant portion of the market. The further advancement of this technology must not only continue to focus on better …

Metodología Para La Aplicación De Un Plan De Mantenimiento Centrado En La Confiabilidad Con Criterios De Administración De Energía En Equipos De Aire Acondicionado Tipo Compacto, A. Zambrano, J. Zambrano, Nelson Fumo

Mechanical Engineering Faculty Publications and Presentations

A través del tiempo han evolucionado filosofías con procedimientos muy diferentes con intereses que pueden llegar a ser comunes en cuanto a su objetivo terminal, es así como se presenta la administración de energía y el mantenimiento centrado en la confiabilidad. Estas teorías buscan en común el adecuado funcionamiento de los sistemas, lograr un uso sostenible con el ambiente a través de un estudio detallado de la causas y efectos de los problemas y averías presentadas. La propuesta presentada constituye un punto intermedio entre ambas filosofías donde se indica la afectación que puede presentar el mal funcionamiento de un equipo …

Merrill-Cazier Library Gas Exhibition, Betty Rozum, Andrew Wesolek, Pamela N. Martin

Education and Outreach

This exhibition, presented in the Merrill-Cazier Library, captured the history and accomplishments of the GAS program. Click the download button to see a PowerPoint presentation featuring images and text from the exhibition.

Model Of A Mechanical Clock Escapement, John Wagner, David Moline, Eugene Vold

Publications

The mechanical tower clock originated in Europe during the 14th century to sound hourly bells and later display hands on a dial. An important innovation was the escapement mechanism, which converts stored energy into oscillatory motion for fixed time intervals through the pendulum swing. Previous work has modeled the escapement mechanism in terms of inelastic and elastic collisions. We derive and experimentally verify a theoretical model in terms of impulsive differential equations for the Graham escapement mechanism in a Seth Thomas tower clock. The model offers insight into the clock’s mechanical behavior and the functionality of the deadbeat escapement mechanism.

Side-By-Side Testing Of Water Heating Systems: Results From The 2010-2011 Evaluation, Florida Solar Energy Center, Carlos Colon

FSEC Energy Research Center®

REVISED MARCH 2013 The Building America (BAPIRC) team at FSEC has released a report containing results from a second testing rotation (Phase II) on seven hot water systems evaluated side-by side. Results show the seasonal performance variation and compares solar systems against electric resistance and the Heat Pump Water Heater (HPWH). Standard and tankless natural gas were also evaluated, where the latter demonstrated a 24% natural gas reduction. The lowest averaged electric power consumptions were demonstrated by the HPWH (2.75 kWh/day) and the PV-pumped solar water heater (3.03 kWh/day). Other testing performed on the HPWH under conditioned and restricted air …