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Finite Element Analysis Of Cracks In Aging Aircraft Structures With Bonded Composite-Patch Repairs, Linxia Gu, Ananth Ram Mahanth Kasavajhala, Shijia Zhao 2010 University of Nebraska-Lincoln

Finite Element Analysis Of Cracks In Aging Aircraft Structures With Bonded Composite-Patch Repairs, Linxia Gu, Ananth Ram Mahanth Kasavajhala, Shijia Zhao

Mechanical & Materials Engineering Faculty Publications

Bonded composite-patch repair has been used to transfer load from cracked structures to the reinforcement such that subsequent crack propagation is reduced. In this study,the mechanical behavior of a single edge v-notch A17075-T6 plate repaired with 1-ply and 4-ply composite patches was investigated through the finite element method. Contour integral method was used to define and evaluate the stress intensity factors at the crack tip. The effect of the adhesive epoxy film, patch material, thickness and ply orientations on the evolution of the stress intensity factor (SIF) of the repaired structure was examined. The results indicated that the SIF ...


Energy Harvesting From Body Motion Using Rotational Micro-Generation, Edwar. Romero-Ramirez 2010 Michigan Technological University

Energy Harvesting From Body Motion Using Rotational Micro-Generation, Edwar. Romero-Ramirez

Dissertations, Master's Theses and Master's Reports - Open

Autonomous system applications are typically limited by the power supply operational lifetime when battery replacement is difficult or costly. A trade-off between battery size and battery life is usually calculated to determine the device capability and lifespan. As a result, energy harvesting research has gained importance as society searches for alternative energy sources for power generation. For instance, energy harvesting has been a proven alternative for powering solar-based calculators and self-winding wristwatches. Thus, the use of energy harvesting technology can make it possible to assist or replace batteries for portable, wearable, or surgically-implantable autonomous systems. Applications such as cardiac pacemakers ...


A Comparison Of Hemodynamic Performance In Mehcanical And Biological Heart Valve Prostheses, Philip Mathew 2010 University of Tennessee at Chattanooga

A Comparison Of Hemodynamic Performance In Mehcanical And Biological Heart Valve Prostheses, Philip Mathew

Masters Theses and Doctoral Dissertations

Heart valve prostheses are used to replace heart valves in patients afflicted with valvular heart disease. The malfunctioning heart valve adversely affects the fluid mechanical performance. While the choice of mechanical VS biological valve prostheses is dependent on the patient, the biological valves should have improved hemodynamic performance compared to the mechanical valves. This work focused on CFD analysis of the Starr-Edwards caged ball valve and a biological valve and serves to validate the improved hemodynamics of the latter valve in comparison to the former. Commercial CFD software (CFD-GEOM, CFD-ACE, CFD-VIEW) are used for the analys is. The main results ...


Design And Fabrication Of Micronozzles For Drug Delivery Applications, Yuxuan Zhou 2010 Louisiana State University and Agricultural and Mechanical College

Design And Fabrication Of Micronozzles For Drug Delivery Applications, Yuxuan Zhou

LSU Master's Theses

Inhaled drug is an important drug delivery route. It is widely used in medications for respiratory disorders. However, it has some significant limitations, for examples, concentration of drug, output, and particles size, are not accurately controlled in most of the available drug delivery systems today. Various new devices and technologies continue to be developed and introduced. Vibrating orifice is one of them. The critical issue of vibrating orifice technology is the fabrication of micro-nozzles. Traditional technique to fabricate these nozzles is to use dry etching method, which tends to be expensive and inconvenient for mass production. Other two optional fabrication ...


Numerical Modeling Of The Shock Tube Flow Fields Before Andduring Ignition Delay Time Experiments At Practical Conditions, mouna lamnaouer 2010 University of Central Florida

Numerical Modeling Of The Shock Tube Flow Fields Before Andduring Ignition Delay Time Experiments At Practical Conditions, Mouna Lamnaouer

Electronic Theses and Dissertations

An axi-symmetric shock-tube model has been developed to simulate the shock-wave propagation and reflection in both non-reactive and reactive flows. Simulations were performed for the full shock-tube geometry of the high-pressure shock tube facility at Texas A&M University. Computations were carried out in the CFD solver FLUENT based on the finite volume approach and the AUSM+ flux differencing scheme. Adaptive mesh refinement (AMR) algorithm was applied to the time-dependent flow fields to accurately capture and resolve the shock and contact discontinuities as well as the very fine scales associated with the viscous and reactive effects. A conjugate heat transfer ...


Nrel: A Year In Clean Energy Innovations: A Review Of Nrel's Feature Stories, National Renewable Energy Laboratory 2010 University of Nevada, Las Vegas

Nrel: A Year In Clean Energy Innovations: A Review Of Nrel's Feature Stories, National Renewable Energy Laboratory

Publications (E)

The National Renewable Energy Laboratory (NREL) is the nation’s primary laboratory for renewable energy and energy efficiency research and development.

NREL’s mission and strategy are focused on advancing the U.S. Department of Energy’s and our nation’s energy goals. The laboratory’s scientists and researchers support critical market objectives to accelerate research from scientific innovations to market-viable alternative energy solutions. At the core of this strategic direction are NREL’s research and technology development competencies. These areas span from understanding renewable resources for energy, to the conversion of these resources to renewable electricity and fuels, and ...


Analysis Of Energyplus For Use In Residential Building Energy Optimization, Justin Sidney Spencer 2010 University of Colorado at Boulder

Analysis Of Energyplus For Use In Residential Building Energy Optimization, Justin Sidney Spencer

Civil Engineering Graduate Theses & Dissertations

This work explored the utility of EnergyPlus as a simulation engine for doing residential building energy optimization, with the objective of finding the modeling areas that require further development in EnergyPlus for residential optimization applications. This work was conducted primarily during 2006-2007, with publication occurring later in 2010. The assessments and recommendations apply to the simulation tool versions available in 2007.

During this work, an EnergyPlus v2.0 (2007) input file generator was developed for use in BEopt 0.8.0.4 (2007). BEopt 0.8.0.4 is a residential Building Energy optimization program developed at the National Renewable ...


Evaluation Of The Performance Of Gas Tankless Water Heaters, Peter William Grant 2010 University of Colorado at Boulder

Evaluation Of The Performance Of Gas Tankless Water Heaters, Peter William Grant

Civil Engineering Graduate Theses & Dissertations

Tankless water heaters (TWHs) are generally thought of as an efficient method of producing hot water, and receive incentives in various federal, state, and utility programs. However, it has up to now been impossible to know the actual efficiency for any specific draw pattern. In addition, TWHs have been used in conjunction with solar systems, and it is uncertain what the impact of pre-heated water will be on THW operation. To address these questions experiments have been performed to fully understand and characterize behavior of TWHs, and a new TRNSYS component has been developed embodying that understanding. The model is ...


An Investigation Of Design Parameters That Affect Commercial High-Rise Office Building Energy Consumption And Demand, Margarete Rois Langner 2010 University of Colorado at Boulder

An Investigation Of Design Parameters That Affect Commercial High-Rise Office Building Energy Consumption And Demand, Margarete Rois Langner

Civil Engineering Graduate Theses & Dissertations

There are many factors that drive energy consumption and demand in high-rise commercial office buildings. Understanding the effects of individual building parameters and two-factor interactions can be very useful for directing building audits, developing energy simulation models, and for building science research in general. In an effort to expedite building audit processes and energy model development, the work presented in this thesis offers strategies and best practices for efficiently conducting audits and developing building energy models. In conjunction, a fractional factorial analysis (FFA) was conducted to evaluate a large number of building parameters in an effort to quantify their effect ...


Computational Models Of Thermal Cycling In Chemical Systems, Carl Barratt, Dante Lepore, Matthew Cherubini, Pauline Schwartz 2010 University of New Haven

Computational Models Of Thermal Cycling In Chemical Systems, Carl Barratt, Dante Lepore, Matthew Cherubini, Pauline Schwartz

Mechanical and Industrial Engineering Faculty Publications

Computational models of chemical systems provide clues to counterintuitive interactions and insights for new applications. We have been investigating models of chemical reaction systems under forced, thermal cycling conditions and have found that some hypothetical processes generate higher yields under thermal cycling than under single, fixed temperature conditions. A simple kinetic model of an actual process, the two-temperature polymerase chain reaction that replicates DNA, is used to simulate the important features of a chemical system operating under thermal cycling. This model provides insights into the design of other chemical systems that may have important applications in chemistry, biochemistry and chemical ...


Process Design For Aeration Of Facial Prosthetic, Nathaniel J. Urciuoli 2010 California Polytechnic State University - San Luis Obispo

Process Design For Aeration Of Facial Prosthetic, Nathaniel J. Urciuoli

Industrial and Manufacturing Engineering

Facial prosthetics are becoming a necessary step for the recovery of injured veterans and civilians who have suffered severe facial burning. Current users of such prosthetics are not able to wear the prosthetic for an extended period of time due to uncomfortable conditions created by the silicone material. A solution for this problem was to develop a process for creating small holes similar to skin pores that will both ventilate and aid in the evaporation of accumulated sweat under the prosthetic.

The main steps of this process were to create a flexible fixture capable of supporting and securing the prosthetic ...


Design And Manufacture Of Tennis Ball Retriever, Philip Hurst 2010 California Polytechnic State University - San Luis Obispo

Design And Manufacture Of Tennis Ball Retriever, Philip Hurst

Industrial and Manufacturing Engineering

No abstract provided.


Design Of A Low Cost Powered R/C Combat Airplane And Manufacturing Plan, Jonathan N. Bailey 2010 California Polytechnic State University - San Luis Obispo

Design Of A Low Cost Powered R/C Combat Airplane And Manufacturing Plan, Jonathan N. Bailey

Industrial and Manufacturing Engineering

The goals of this project are to design a low cost powered remote control combat airplane capable of outdoor flight, named the Aero EX and to develop a manufacturing plan to produce each unit at a selling price of $200, while operating at a 25 vehicle batch rate inside a 1,000 square foot facility. These goals are achieved using: Aerospace fundamentals to design the vehicle, Design for Manufacturability to optimize the design for minimal use of labor, Design for Assembly to give consumers the ability to build the vehicle without fixtures, Pull production to eliminate scheduling and match customer ...


Gravitational Effects On Thin-Wire Subcooled Nucleate Boiling Dynamics, Justin Koeln, Andrew Fassmann, Troy Munro, Rob Barnett 2010 Utah State University

Gravitational Effects On Thin-Wire Subcooled Nucleate Boiling Dynamics, Justin Koeln, Andrew Fassmann, Troy Munro, Rob Barnett

Presentations

No abstract provided.


Engineering Sport Safety: A Study Of Equestrian Cross Country Eventing, Katherine M. Kahmann 2010 University of Kentucky

Engineering Sport Safety: A Study Of Equestrian Cross Country Eventing, Katherine M. Kahmann

University of Kentucky Master's Theses

The sport of equestrian cross country eventing has seen many serious and even fatal injuries due to rotational horse falls in recent years. The sport originally consisted of horse and rider teams jumping stationary, wood fences. However, in a move towards increasing safety for horses and riders, frangible and deformable safety devices have been emerging in the field. This thesis provides an overview of safety designs that are currently available and those that are on the horizon. Also, a path-finder method of evaluating and developing safety fence designs was outlined and applied to two distinct designs, a hinged gate and ...


Uv-Lithographic Patterning Of Micro-Features On A Conical Mold Insert, Justin P. Huber 2010 University of Kentucky

Uv-Lithographic Patterning Of Micro-Features On A Conical Mold Insert, Justin P. Huber

University of Kentucky Master's Theses

In past studies, several techniques have been employed to create microscopic features on relatively simple surfaces. Of these, lithography-based techniques have proven effective at manufacturing large fields of deterministic microasperities and microcavities on planar and cylindrical substrates. The present study focuses on adapting UV-lithography to a more complex substrate. Machined from stainless steel, a conical mold insert introduces an interesting geometry designed for the injection molding of radial lip seal elastomer. The distinct shape of this mold insert poises unique challenges to a conventional lithography procedure. Spray application is investigated as a feasible means to deposit layers of photoresist on ...


Characterization Of Defects In Metal Sheets Via Infrared Thermography, Marc Anthony Harik 2010 University of Kentucky

Characterization Of Defects In Metal Sheets Via Infrared Thermography, Marc Anthony Harik

University of Kentucky Master's Theses

Defects in Aluminum, Stainless steel and galvanized steel sheets are studied in reflection mode infrared thermography. The effect of material properties, surface finish, heating intensity, heater emission spectra, pixel size and defect size are studied. Contrast is governed by heat quality, emissivity and defect geometry—which follows a logarithmic trend. The diameter detected via infrared thermography is found to be at least 30% larger than the measured diameter and sub-pixel defects can be detected. The use of gradient and Laplacian of temperature is introduced as a means of increasing defect contrast and mitigating heater variation.


An Mpi-Cuda Implementation For Massively Parallel Incompressible Flow Computations On Multi-Gpu Clusters, Dana A. Jacobsen, Julien C. Thibault, Inanc Senocak 2010 Boise State University

An Mpi-Cuda Implementation For Massively Parallel Incompressible Flow Computations On Multi-Gpu Clusters, Dana A. Jacobsen, Julien C. Thibault, Inanc Senocak

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Modern graphics processing units (GPUs) with many-core architectures have emerged as general-purpose parallel computing platforms that can accelerate simulation science applications tremendously. While multi-GPU workstations with several TeraFLOPS of peak computing power are available to accelerate computational problems, larger problems require even more resources. Conventional clusters of central processing units (CPU) are now being augmented with multiple GPUs in each compute-node to tackle large problems. The heterogeneous architecture of a multi-GPU cluster with a deep memory hierarchy creates unique challenges in developing scalable and efficient simulation codes. In this study, we pursue mixed MPI-CUDA implementations and investigate three strategies to ...


Effect Of Electrical Double Layer On Electric Conductivity And Pressure Drop In A Pressure-Driven Microchannel Flow, Heng Ban, Bochuan Lin, Zhourui Song 2010 Utah State University - Faculty Advisor

Effect Of Electrical Double Layer On Electric Conductivity And Pressure Drop In A Pressure-Driven Microchannel Flow, Heng Ban, Bochuan Lin, Zhourui Song

Mechanical and Aerospace Engineering Faculty Publications

The effect of an electrical double layer (EDL) on microchannel flow has been studied widely, and a constant bulk electric conductivity is often used in calculations of flow rate or pressure drop. In our experimental study of pressure-driven micropipette flows, the pipette diameter is on the same order of magnitude as the Debye length. The overlapping EDL resulted in a much higher electric conductivity, lower streaming potential, and lower electroviscous effect. To elucidate the effect of overlapping EDL, this paper developed a simple model for water flow without salts or dissolved gases (such as CO2) inside a two-dimensional microchannel ...


Accelerated Lattice Boltzmann Method For Colloidal Suspensions Rheology And Interface Morphology, Hassan Farhat 2010 Wayne State University

Accelerated Lattice Boltzmann Method For Colloidal Suspensions Rheology And Interface Morphology, Hassan Farhat

Wayne State University Dissertations

ABSTRACT

ACCELERATED LATTICE BOLTZMANN MODEL FOR COLLOIDAL SUSPENSIONS RHEOLOGY AND INTERFACE MORPHOLOGY

by

HASSAN FARHAT

July 2010

Advisor: Dr. Singh Trilochan

Co-Advisor: Dr. Joon Sang Lee

Major: Mechanical Engineering

Degree: Doctor of Philosophy

Colloids are ubiquitous in the food, medical, cosmetic, polymer, water purification and pharmaceutical industries. Colloids thermal, mechanical and storage properties are highly dependent on their interface morphology and their rheological behavior.

Numerical methods provide a cheap and reliable virtual laboratory for the study of colloids. However efficiency is a major concern to address when using numerical methods for practical applications.

This work introduces the main building-blocks for ...


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