Digital Commons Network^™

Numerical Modeling Of Infrared Thermography Techniques Via Ansys, Hayder Abdulnabi Thajeel

Masters Theses

"Several inspection techniques have been developed over years. Recently, infrared thermography (IRT) technology has become a widely accepted as a nondestructive inspection (NDI) technique for different fields and various applications as well. Infrared thermography stands as one of the most an attractive and a successful NDI technique that has ability to detect the object's surface/subsurface defects remotely based on observing and measuring the surface's emitted infrared heat radiation by using an infrared camera. The finite element modeling FEM ANSYS was successfully used for the modelling of several IRT techniques; such as Pulsed Thermography (PT) and Lock-in Thermography (LT) that can …

Buckling, Postbuckling And Imperfection Sensitivity Analysis Of Different Type Of Cylindrical Shells By Hui's Postbuckling Method, Hailan Xu

University of New Orleans Theses and Dissertations

Hui and Chen (1986) were the first to show that the well-known Koiter’s General Theory of Elastic Stability of 1945 can be significantly improved by evaluating the postbuckling b coefficient at the actual applied load, rather than at the classical buckling load. Such improvement method was demonstrated to be (1) very simple to apply with no tedious algebra, (2) significant reduction in imperfection sensitivity and (3) although it is still asymptotically valid, there exists a significant extension of the range of validity involving larger imperfection amplitudes. Strictly speaking, Koiter’s theory of 1945 is valid only for vanishingly small imperfection amplitudes. …

Experimental Investigation Of Mist Film Cooling And Feasibility Study Of Mist Transport In Gas Turbines, Reda M. Ragab

University of New Orleans Theses and Dissertations

In the modern advanced gas turbines, the turbine inlet temperature may exceed 1500°C as a requirement to increase power output and thermal efficiency. Therefore, it is imperative that the blades and vanes are cooled so they can withstand these extreme temperatures. Film cooling is a cooling technique widely used in high-performance gas turbines. However, the film cooling effectiveness has almost reached plateau, resulting in a bottleneck for continuous improvement of gas turbines' efficiency.

In this study, an innovative cooling scheme, mist film cooling is investigated through experiments. A small amount of tiny water droplets with an average diameter about 10-15 …

A Wedge Impact Theory Used To Predict Bow Slamming Forces, Ashok Benjamin Basil Attumaly

University of New Orleans Theses and Dissertations

The pressures and impact forces acting on a hull while experiencing bow wave slamming is analyzed using Vorus' Impact Theory. The theory extends the hydrodynamic analysis of planing hulls from simple wedges to irregular shapes using a Boundary Element Method. A Fortran-based code developed by the Author is used to analyze hullforms. Linear strip theory is used to extend the analysis over a three dimensional hull. Post-processing of output data gives hull pressure distributions at different time steps and is visually presentable.

Impact pressure, Impact force, Planing, Wave slamming, Bow impact, Vorus' theory, Boundary Element Method, Linear strip theory

Rocket Motor Diagnostics Using Tunable Diode Laser Spectroscopy For Chemically Non-Reacting Air/Water Vapor Mixture In Internal Flow, Wesley Carleton

University of New Orleans Theses and Dissertations

This research is for the implementation of non-intrusive measurement techniques in the study of high temperature pipe flow. A low pressure, laboratory scale hybrid rocket motor simulator was built to achieve high temperatures with various gases. A quartz test section was designed, built, and implemented into the existing test setup to accommodate the laser beam of the existing Tunable Diode Laser Absorption Spectrometer (TDLAS) system which was designed to observe water vapor. A super-heated water vapor injector was designed to obtain the desired water vapor concentrations. Flow characteristics were simultaneously recorded using the existing TDLAS system and the DAQ system …

A Numerical Study Of High Temperature And High Velocity Gaseous Hydrogen Flow In A Cooling Channel Of A Ntr Core, Sajan B. Singh

University of New Orleans Theses and Dissertations

Two mathematical models (a one and a three-dimensional) were adopted to study, numerically, the thermal hydrodynamic behavior of flow inside a single cooling channel of a Nuclear Thermal Rocket (NTR) engine. The first model assumes the flow in the cooling channel to be one-dimensional, unsteady, compressible, turbulent, and subsonic. The working fluid (GH₂) is assumed to be compressible. The governing equations of the 1-D model are discretized using a second order accurate finite difference scheme. Also, a commercial CFD code is used to study the same problem. Numerical experiments, using both codes, simulated the flow and heat transfer …

A Study On The Integration Of A Novel Absorption Chiller Into A Microscale Combined Cooling, Heating, And Power (Micro-Cchp) System, Scott J. Richard

University of New Orleans Theses and Dissertations

This study explores the application of micro-CCHP systems that utilize a 30 kW gas microturbine and an absorption chiller. Engineering Equation Solver (EES) is used to model a novel single-effect and double-effect water-lithium bromide absorption chiller that integrates the heat recovery unit and cooling tower of a conventional CCHP system into the chiller’s design, reducing the cost and footprint of the system. The results of the EES model are used to perform heat and material balances for the micro-CCHP systems employing the novel integrated chillers, and energy budgets for these systems are developed. While the thermal performance of existing CCHP …

Fundamental Experimental Studies In Scaling, Blast Mitigation And Material Processing, Xing Zhao

Theses and Dissertations

In this work, two separate research efforts are discussed. They include experimental studies in (1) Scaling and Blast Mitigation and (2) Scaling in Friction Stir Extrusion. In both studies, the primary experimental measurement method is three-dimensional digital image correlation (3D-DIC), a non-contacting full-field measurement method that is applicable for both high-rate loading and quasi-static loading conditions.

Scaling and Blast Mitigation Studies:

A series of properly scaled structures was subjected to buried blast loading conditions via detonation of a small explosive buried in saturated sand. Using high speed stereo-vision systems to record the deformations of selected regions on the upper surface …

An Experimental Analysis Of The Weighted Sum Of Spatial Gradients Minimization Quantity In Active Structural Acoustic Control Of Vibrating Plates, Daniel R. Hendricks

Theses and Dissertations

Active Structural Acoustic Control (ASAC) is a subcategory of the more widely known field of Active Noise control (ANC). ASAC is different from traditional ANC methods because it seeks to attenuate noise by altering the noise producing structure instead of altering the acoustic waves traveling through the air. The greatest challenge currently facing ASAC researchers is that a suitable parameter has not yet been discovered which can be easily implemented as the minimization quantity in the control algorithms. Many parameters have been tried but none effectively attenuate the sound radiation in a way that can be easily implemented. A new …

Effect Of Full-Annular Pressure Pulses On Axial Turbine Performance, Mark H. Fernelius

Theses and Dissertations

Pulse detonation engines show potential to increase the efficiency of conventional gas turbine engines if used in place of the steady combustor. However, since the interaction of pressure pulses with the turbine is not yet well understood, a rig was built to compare steady flow with pulsing flow. Compressed air is used in place of combustion gases and pressure pulses are created by rotating a ball valve with a motor. This work accomplishes two main objectives that are different from previous research in this area. First, steady flow through an axial turbine is compared with full annular pulsed flow closely …

Methods For Fabricating Printed Electronics With High Conductivity And High Resolution, Tengyuan Zhang

Electronic Thesis and Dissertation Repository

Flexible and printable electronics are attractive techniques which are believed to be widespread and occupy huge market. However, low conductivity, nozzle clog because of the accumulation of nano-particles and relative high cost (expensive silver/copper nanoparticle inks) limit its appeal. In this thesis, two new effective and convenient methods of fabricating copper patterns with high conductivity and strong adhesion on flexible photopaper and polymer substrates (PET) are demonstrated, solving all those problems. Functional photopaper and PET substrate was prepared with inkjet printing of a palladium salt solution and hyperthermal hydrogen induced cross-linking (HHIC) polyelectrolytes onto its surface respectively, followed by electroless …

Active Structural Acoustic Control Of Clamped And Ribbed Plates, William Richard Johnson

Theses and Dissertations

A control metric, the weighted sum of spatial gradients (WSSG), has been developed for use in active structural acoustic control (ASAC). Previous development of WSSG [1] showed that it was an effective control metric on simply supported plates, while being simpler to measure than other control metrics, such as volume velocity. The purpose of the current work is to demonstrate that the previous research can be generalized to plates with a wider variety of boundary conditions and on less ideal plates. Two classes of plates have been considered: clamped flat plates, and ribbed plates. On clamped flat plates an analytical …

Computational And Experimental Study Of Degeneration, Damage And Failure In Biological Soft Tissues, Gregory Allen Von Forell

Theses and Dissertations

The purpose of this work was to analyze the biomechanics of degeneration, damage, and failure in biological soft tissues both experimentally and computationally to provide insight into tendon or ligament tearing, tendo-achilles lengthening and lumbar spine dysfunction. For soft tissue tearing, experimental studies for calculating fracture toughness were performed and determined that tendons and ligaments are able to completely resist tear propagation. For tendo-achilles lengthening, a damage model was developed to mimic the behavior of the lengthening that occurs as a result of the percutaneous triple hemisection technique. The model provided insight for predicting the amount of lengthening that occurs …

Development And Validation Of An Absorption Sensor For Time-Resolved Measurements Of Co And Co2, Kyle Thurmond

HIM 1990-2015

A sensor was developed for simultaneous measurements of carbon monoxide and carbon dioxide fluctuations in internal combustion engine exhaust gases. This sensor utilizes low-cost and compact LEDs that emit in the 3-5[micro]m wavelength range which are more appropriate for practical applications than the more traditionally used lasers. An affordable, fast response sensor that can measure these gases has broad application that can lead to more efficient, fuel flexible engines and regulations of harmful emissions. LEDs have a more spectrally broad and diverging emission than lasers which presented many design challenges. The optical design software ZEMAX was utilized to overcome these …

Fracture Toughness Of A Hyperelastic Material During Surgical Cutting, Kevin Smith

HIM 1990-2015

Despite being one of the most important organs of vertebrates, the material properties of skin are also one of the most poorly understood. In the field of designing medical devices and surgical tools there are significant advantages to having a model that describes the interaction of forces between a blade tip and skin during surgical cutting. In general, skin can best be described as a composite layer consisting of a viscoelastic dermis with interwoven collagen and elastin fibers beneath a superficial epidermis. The purpose of this research is to study the fracture toughness of porcine skin during practical cutting applications, …

Characterization Of Polyetherimide Under Static, Dynamic, And Multiple Impact Conditions, Bryan Zuanetti

HIM 1990-2015

The application of polymers in robust engineering designs is on the rise due to their excellent mechanical properties such as high fracture toughness, specific strength, durability, as well as, thermal and chemical resistances. Implementation of some advanced polymeric solids is limited due to the lack of available mechanical properties. In order for these materials to endure strenuous engineering designs it is vital to investigate their response in multiple loading rates and conditions. In this thesis, the mechanical response of polyethermide (PEI) is characterized under quasi-static, high strain rate, and multiple impact conditions. Standard tension, torsion, and compression experiments are performed …

Equipment Maintenance And Replacement Decision Making Processes, Michael W. Gage

Industrial and Manufacturing Engineering

This project contains recommendations for the decision making processes for support and production equipment maintenance and replacement for a large defense contractor. Recent literature has been reviewed to provide perspective on current trends in the field. A complete evaluation of their current processes and systems is included with recommendations on areas for improvement. A decision support system is also proposed to supplement their existing decision making.

S1nn Gmbh & Co. Kg (Automobile Connectivity Module 1.1), Tyler Alexander Ball

Industrial and Manufacturing Engineering

The results of this report show how when diagnostics were run on the Connectivity Module 1.1, the problems discovered such as potential short-circuiting, 90-degree copper tracing angles, and components overheating/tombstoning were addressed. By using the method of “DMAIC,” which stands for Design, Measure, Analyze, Implement, Control, successful corrections were made. In the first design of the Printed Circuit Board (PCB), 1454 critical issues were found. With the newly designed PCB’s modifications being implemented, only 12 critical issues remained, which were later addressed and corrected. The results from this report are a functional Automobile Connectivity Module 1.1.

Project Management Of High School Shadow And Building An Engineer Day, Andrea M. Carroll

Industrial and Manufacturing Engineering

Building an Engineer Day and High School Shadow are semi-annual outreach events hosted by Cal Poly’s Society of Women Engineers section during fall and spring quarters. The events focus on encouraging women and minorities to take an interest in engineering. These events are the two largest outreach events hosted by The Society of Women Engineers and need to run smoothly in order to provide student attendees with a meaningful experience.

Building an Engineer Day and High School Shadow are currently un-organized and un-planned, which leads to problems with officer retention, increase in expediting process and a low attendance rate at …

Fixture For Carbon Fiber Spar Of Human Powered Helicopter, David John Ikeda, Luis Gonzalez

Industrial and Manufacturing Engineering

The following report describes our contribution to Cal Poly Human Powered Helicopter for the 2012 competition for the Sikorsky Prize offered by the American Helicopter Society. In order to win this prize the team needs to build and fly a human powered helicopter for more than 60 seconds reaching and altitude of 3 meters while staying in a 10 meter square box. Our team was created to support the integration of Carbon Fiber parts, specifically the carbon fiber spars with rotor and landing gears. Precise cutting and accurate drilling was needed and our team was tasked with creating a fixture …

Gait And Locomotion Analysis For Tribological Applications, Md Hayder Ali

Theses and Dissertations

No abstract provided.

Wind Turbine Controls For Farm And Offshore Operation, Zhongzhou Yang

Theses and Dissertations

Development of advanced control techniques is a critical measure for reducing the cost of energy for wind power generation, in terms of both enhancing energy capture and reducing fatigue load. There are two remarkable trends for wind energy. First, more and more large wind farms are developed in order to reduce the unit-power cost in installation, operation, maintenance and transmission. Second, offshore wind energy has received significant attention when the scarcity of land resource has appeared to be a major bottleneck for next level of wind penetration, especially for Europe and Asia. This dissertation study investigates on several wind turbine …

Finite Element Analysis Of Contribution Of Adhesion And Hysteresis To Shoe-Floor Friction, Seyed Reza Mirhassani Moghaddam

Theses and Dissertations

Slips and falls are one of the leading causes of occupational accidents. Understanding the important factors that affect shoe-floor friction is vital for identifying unsafe surfaces and designing better footwear and flooring. While the shoe-floor coefficient of friction is known to be dependent on several factors including shoe and floor roughness, shoe speed, shoe material, and normal load, the mechanisms that cause these effects are not very well understood. The objective of this thesis is to develop a finite element model that simulates the microscopic asperity interaction between shoe and floor surfaces and apply it to quantify the effect of …

Crack Growth Behavior Under Creep-Fatigue Conditions Using Compact And Double Edge Notch Tension-Compression Specimens, Santosh B. Narasimha Chary

Graduate Theses and Dissertations

The American Society for Testing and Materials (ASTM) has recently developed a new standard for creep-fatigue crack growth testing, E 2760-10, that supports testing compact specimens, C(T), under load controlled conditions. C(T) specimens are commonly used for fatigue and creep-fatigue crack growth testing under constant-load-amplitude conditions. The use of these specimens is limited to positive load ratios. They are also limited in the amount of crack growth data that can be developed at high stress intensity values due to accumulation of plastic and/or creep strains leading to ratcheting in the specimen. Testing under displacement control can potentially address these shortcomings …

Trampoline And Bungee Fatigue-Test Machine, Andy Brock, Christopher D'Elia, Ryan Murphy

Mechanical Engineering

JumpSport, a Saratoga based recreational and fitness trampoline company, sponsored this senior project team towards the development of a fatigue-testing machine. The goal of this project was to iterate the previous machine JumpSport used for bungee cord, spring, and trampoline fatigue testing. Since minimal study had been conducted on these specific bungee cords, the fixture was designed to confirm the theoretical correlations for rubber and perform the final tests according to a strict protocol. Operating with a specific test protocol in mind will allow the data from multiple tests to be combined and analyzed statistically. With a design concept in …

In-Bottle Wine Aerator, Kevin Kesler, Patrick Lowry, Paul Woolworth

Mechanical Engineering

The proposal for Capitol Cultivators discusses and evaluates the development of an in-bottle wine aerator. It defines the problem and need for an aerator located inside the wine bottle. Additionally, it outlines requirements essential for an effective design and describes the engineering process that will be followed.

Development Of A Hybrid Vehicle Powertrain Test Laboratory, Bennet Samuel Soundarraj

Doctoral Dissertations and Master's Theses

During the last two years, Embry-Riddle Aeronautical University has installed and tested a fully functional eddy-current chassis dynamometer testing facility on campus. An automotive test facility requires a systems engineering approach to install, calibrate and commission a chassis dynamometer. This thesis shows that, the dynamometer test facility was successfully installed, commissioned and documented to safely support the power train development and testing. We can currently test the EcoCAR vehicle and a number of other front-wheel-drive vehicles at our university campus using the eddy current chassis dynamometer.

Characterization Techniques And Electrolyte Separator Performance Investigation For All Vanadium Redox Flow Battery, Zhijiang Tang

Doctoral Dissertations

The all-vanadium redox flow battery (VRFB) is an excellent prospect for large scale energy storage in an electricity grid level application. High battery performance has lately been achieved by using a novel cell configuration with advanced materials. However, more work is still required to better understand the reaction kinetics and transport behaviors in the battery to guide battery system optimization and new battery material development. The first part of my work is the characterization of the battery systems with flow-through or flow-by cell configurations. The configuration difference between two cell structures exhibit significantly different polarization behavior. The battery output can …

Understanding The Role Of Requirements In Engineering Design By Novices, Shraddha Joshi

All Dissertations

Requirements play a critical role in the design process. The broader impact of this research is to develop a systematic understanding of the current use of requirements with an ultimate goal to develop guidelines and recommendations for more effective use of requirements throughout the design process. Thus, this research begins to answer the question about what is the role of requirements in design process and, specifically, its role in idea generation? The answer to this question is explored in three phases. The first phase is to understand how requirements are currently taught to students. To that end, two surveys were …

Analytical Solutions For A Large-Scale Long-Lived Rotating Layer Of Fluid Heated Underneath, Pouya Jalilian

Masters Theses

In this work, the system of equations for a large- scale long lived rotating layer of fluid with the deformable upper free surface and non-deformable lower free surface heated underneath has been reviewed and derived. The quasi-geostrophic approximation, the beta effect and the method of multi-scale expansions have been employed to and as a result, an equation governing the evolution of large-scale perturbations, has been derived. The effect of each term present in the upper surface deformation equation has been analyzed and the analytical solutions have been obtained by virtue of employing auxiliary Riccati equation method. The soliton solutions obtained …