Mechanical Engineering Commons^™

A Mathematical Evaluation Of Hemodynamic Parameters After Carotid Eversion And Conventional Patch Angioplasty, Alexey Kamenskiy, Iraklis I. Pipinos, Yuris A. Dzenis, Prateek K. Gupta, Syed A. Jaffar Kazmi, Jason N. Mactaggart

Department of Mechanical and Materials Engineering: Faculty Publications

Carotid endarterectomy has a long history in stroke prevention, yet controversy remains concerning optimal techniques. Two methods frequently used are endarterectomy with patch angioplasty (CEAP) and eversion endarterectomy (CEE). The objective of this study was to compare hemodynamics-related stress and strain distributions between arteries repaired using CEAP and CEE. Mathematical models were based on in vivo three-dimensional arterial geometry, pulsatile velocity profiles, and intraluminal pressure inputs obtained from 16 patients with carotid artery disease. These data were combined with experimentally derived nonlinear, anisotropic carotid artery mechanical properties to create fluid-structure interaction models of CEAP and CEE. These models were then …

Effects Of Mode Coupling On The Admittance Of An At-Cut Quartz Thickness-Shear Resonator, Huijing He, Jiashi Yang, Wei-Ping Zhang, Ji Wang

Department of Mechanical and Materials Engineering: Faculty Publications

We study the effects of couplings to flexure and face-shear modes on the admittance of an AT-cut quartz plate thickness-shear mode resonator. Mindlin’s two-dimensional equations for piezoelectric plates are employed. Electrically forced vibration solutions are obtained for three cases: pure thickness-shear mode alone; two coupled modes of thickness shear and flexure; and three coupled modes of thickness shear, flexure, and face shear. Admittance is calculated and its dependence on the driving frequency and the length/thickness ratio of the resonator is examined. Results show that near the thickness-shear resonance, admittance assumes maxima, and that for certain values of the length/thickness ratio, …

A Comparative Study Of Three Different Chemical Vapor Deposition Techniques Of Carbon Nanotube Growth On Diamond Films, Betty T. Quinton, Paul N. Barnes, Chakrapani V. Varanasi, Bang-Hung Tsao, Kevin J. Yost, Sharmila M. Mukhopadhyay

Mechanical and Materials Engineering Faculty Publications

This paper compares between the methods of growing carbon nanotubes (CNTs) on diamond substrates and evaluates the quality of the CNTs and the interfacial strength. One potential application for these materials is a heat sink/spreader for high-power electronic devices. The CNTs and diamond substrates have a significantly higher specific thermal conductivity than traditional heat sink/spreader materials making them good replacement candidates. Only limited research has been performed on these CNT/diamond structures and their suitability of different growth methods. This study investigates three potential chemical vapor deposition (CVD) techniques for growing CNTs on diamond: thermal CVD (T-CVD), microwave plasma-enhanced CVD (MPE-CVD), …

Nanomaterials Synthesis, Applications, And Toxicity 2012, Mallikarjuna Nadagouda, Dionysios Demetriou Dionysiou, Darren A. Lytle, Thomas F. Speth, Sharmila M. Mukhopadhyay

Mechanical and Materials Engineering Faculty Publications

Nanotechnology presents new opportunities to create better materials and products. Nanomaterials find wide applications in catalysis, energy production, medicine, environmental remediation, automotive industry, and other sectors of our society. Nanomaterial-containing products are already available globally and include automotive parts, defense application, drug delivery devices, coatings, computers, clothing, cosmetics, sports equipment, and medical devices. This special issue includes emerging advances in the field, with a special emphasis given to nanomaterial synthesis and applications.

Agent Based, Distributed Control Strategies And Optimization Of Plug-In Electric Vehicles On Smart/Microgrid Architectures, Kyle Bordeau

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

This thesis will present strategies for the use of plug-in electric vehicles on smart and microgrids. MATLAB is used as the design tool for all models and simulations.

First, a scenario will be explored using the dispatchable loads of electric vehicles to stabilize a microgrid with a high penetration of renewable power generation. Grid components for a microgrid with 50% photovoltaic solar production will be sized through an optimization routine to maintain storage system, load, and vehicle states over a 24-hour period. The findings of this portion are that the dispatchable loads can be used to guard against unpredictable losses …

Driver Safety In Far-Side And Far-Oblique Crashes: A Study Of Patrol Vehicles In The United States Of America, Martin Sepoori

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

The dissertation titled "Driver Safety in Far-side and Far-oblique Crashes" presents a novel approach to assessing vehicle cockpit safety by integrating Human Factors and Applied Mechanics. The methodology of this approach is aimed at improving safety in compact mobile workspaces such as patrol vehicle cockpits.

A statistical analysis performed using Michigan state's traffic crash data to assess various contributing factors that affect the risk of severe driver injuries showed that the risk was greater for unrestrained drivers (OR=3.38, p<0.0001) and for incidents involving front and far-side crashes without seatbelts (OR=8.0 and 23.0 respectively, p<0.005). Statistics also showed that near-side and far-side crashes pose similar threat to driver injury severity. A Human Factor survey was conducted to assess various Human-Machine/Human-Computer Interaction aspects in patrol vehicle cockpits. Results showed that tasks requiring manual operation, especially the usage of laptop, would require more attention and potentially cause more distraction. A vehicle survey conducted to evaluate ergonomics-related issues revealed that some of the equipment was in airbag deployment zones. In addition, experiments were conducted to assess the effects on driver distraction caused by changing the position of in-car accessories. A driving simulator study was conducted to mimic HMI/HCI in a patrol vehicle cockpit (20 subjects, average driving experience = 5.35 years, s.d. = 1.8). It was found that the mounting locations of manual tasks did not result in a significant change in response times. Visual displays resulted in response times less than 1.5sec. It can also be concluded that the manual task was equally distracting regardless of mounting positions (average response time was 15 secs). Average speeds and lane deviations did not show any significant results.

Data from 13 full-scale sled tests conducted to simulate far-side impacts at 70 PDOF and 40 PDOF was used to analyze …

Nebraska Summary: S922 Massey Ferguson 7615, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: 913 Challenger Mt525d, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Test 2062: Challenger Mt765d, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Effect Of Aviation Fuel Type And Fuel Injection Conditions On The Spray Characteristics Of Pressure Swirl And Hybrid Air Blast Fuel Injectors, Rick Thomas Feddema

Open Access Theses

Feddema, Rick T. M.S.M.E., Purdue University, December 2013. Effect of Aviation Fuel Type and Fuel Injection Conditions on the Spray Characteristics of Pressure Swirl and Hybrid Air Blast Fuel Injectors. Major Professor: Dr. Paul E. Sojka, School of Mechanical Engineering

Spray performance of pressure swirl and hybrid air blast fuel injectors are central to combustion stability, combustor heat management, and pollutant formation in aviation gas turbine engines. Next generation aviation gas turbine engines will optimize spray atomization characteristics of the fuel injector in order to achieve engine efficiency and emissions requirements.

Fuel injector spray atomization performance is affected by the …

Effects Of Strain Energy Release Rate On Delamination In Temperature Environment, Venkata Naga Ravitej Sankarabatla

Mechanical and Aerospace Engineering Theses - Archive

Delamination is the weakest and major failure mode in laminated composites. Extensive efforts on initiation and growth of delamination under mechanical load have been investigated. A little emphasis was made earlier to account for the delamination in laminates under temperature loading. Strain energy release rate, a fracture mechanics parameter has been widely accepted to use for study the characteristics of delamination growth. In order to conduct a quick assessment of delamination growth, a closed form expression is developed to quantify the strain energy release rate of the laminate subjected to temperature environment. A finite element model is also developed to …

Investigation Of Side Wall Effects On An Inward Scramjet Inlet At Mach Number 8.6, Tiago Cavalcanti Rolim

Mechanical and Aerospace Engineering Dissertations - Archive

Experimental and computational studies were conducted to evaluate the performance of a scramjet inlet as the side cowl length is changed. A slender inward turning inlet with a total length of 304.8 mm, a span of 50.8 mm with a top and a bottom compression ramp each at 11.54 deg and a compression ratio of 4.79 was used. The side cowl lengths were of 0, 50.8 and 76.2 mm. The UTA Hypersonic Shock Tunnel facility was used in the reflected mode to test the inlet model. The model was instrumented with nine piezoelectric pressure transducers, for static and total pressure …

Development Of Artificial Neural Network Based Black Box Model Of A Data Center As A Temperature Predicting Tool As A Function Of Server Location, Dissipating Server Heat And Crac Fan Speed, Chinmay N. Date

Mechanical and Aerospace Engineering Theses - Archive

Modern data centers consume an astonishing 1.3\% power all around the world. As the number of data centers continue to grow, there is an increasing need and demand to develop new ways to reduce the power footprint. Several approaches are being made to achieve this. One of such several approaches is to develop control systems that would keep the data centers running energy efficiently. Various control theories have been developed throughout the world to achieve the optimal energy efficient state. However, during the synthesis of such control schemes, the CFD simulations take up excessive time for plotting the thermal map …

Development Of Multi-Element Active Aerodynamics For The Formula Sae Car, James Patrick Merkel

Mechanical and Aerospace Engineering Theses - Archive

This thesis focuses on the design, development, and implementation of an active aerodynamics system on 2013 Formula SAE car. The aerodynamics package itself consists of five element front and rear wings as well as an under body diffuser. Five element wings produce significant amounts of drag which is a compromise between the cornering ability of the car and the acceleration capability on straights. The active aerodynamics system allows for the wing angle of attack to dynamically change their configuration on track based on sensory data to optimize the wings for any given scenario. The wings are studied using computational fluid …

The Samara Spacecraft: Design And Development Of A Self-Stabilizing, Auto-Rotating, Distributed Sensing System, Amit Desai Lalloobhai

Mechanical and Aerospace Engineering Theses - Archive

The scope of this research is the design and development of a self-stabilizing re-entry vehicle that closely resembles naturally occurring seeds in nature. It was hypothesized that a femto-satellite with a shape of a samara could self stabilize and passively generate lift, as well as transmit a signal during its descent through the atmosphere. The research included a conceptual design phase and a preliminary design phase that entailed analytic simulations, and an experimental demonstration. The goal was to investigate the feasibility of developing the above-mentioned femto-vehicle that could increase the range capability of its descent to maximize data capture.

Development And Operation Of An Integrated Sampling Probe And Gas Analyzer For Turbulent Mixing Studies In Complex Supersonic Flows, John D. Wiswall

Mechanical and Aerospace Engineering Theses - Archive

For many aerospace applications, mixing enhancement between co-flowing streams has been identified as a critical and enabling technology. Due to short fuel residence times in scramjet combustors, combustion is limited by the molecular mixing of hydrogen (fuel) and air. Determining the mixedness of fuel and air in these complex supersonic flowfields is critical to the advancement of novel injection schemes currently being developed at UTA in collaboration with NASA Langley and intended to be used on a future two-stage to orbit (~Mach 16) hypersonic air-breathing vehicle for space access.Expanding on previous work, an instrument has been designed, fabricated, and tested …

Numerical Study Of Incompressible Fluid Flow In A Vertically Dropping Pool With And Without End Sill, Vimal Ramanuj

Mechanical and Aerospace Engineering Theses - Archive

The study involves numerical analysis of flow field for three different flow regimes taking place in a vertically dropping pool. In general, a vertically dropping flow generates a skimming flow regime with one recirculation zone along with a developing shear layer. The presence of an obstacle (end sill) results in the formation of another recirculation zone downstream of the impinging jet. Based on the nature of these zones, the flow is categorized as napped, periodically oscillatory and skimming. The type of flow regime depends on the flow parameters like velocity and depth of flow which are controlled by Froude number. …

3-D Fracture Study Of The Beol Cu/Low-K Stack To Assess And Mitigate The Cpi Risk During The Reflow Process, Zaeem Baig

Mechanical and Aerospace Engineering Theses - Archive

As scaling of components continues, using SiO2 as a dielectric in the Back-End-Of-Line (BEoL) is no longer a viable option and can be replaced with low-k and ultralow-k (ULK) dielectric materials for advanced integrated circuits (IC) packaging solutions. The low-k materials improve performance by reducing parasitic capacitance and crosstalk between adjacent metal lines. However, low-k dielectrics have lower modulus, lower fracture toughness, higher coefficient of thermal expansion (CTE), and poor adhesion as compared to SiO2. Thus, low-k dielectric integration in the contemporary IC packages poses a significant reliability challenge. Delamination along the metal-dielectric interfaces and crack propagation in the dielectric …

A Novel Approach For Two-Dimensional Inclusion/Hole Problems Using The Airy Stress Function Method, Manikandan Madhavan

Mechanical and Aerospace Engineering Theses - Archive

This thesis demonstrates the application of the Airy stress function in solving plane elasticity problems. An Airy stress function is determined for two-dimensional infinite plates containing a circular inclusion embedded with a circular hole subjected to tensile loading and the traction and displacement functions for various boundary conditions satisfy the equilibrium and continuity conditions. Mathematica was useful for solving the complex expressions and to calculate the elastic fields for a variety of elastic problems in this study.

Modeling The Dynamic Behavior Of Estrogen Docking Into Its Receptor Using The Multiscale Analysis, Anudeep Palanki

Mechanical and Aerospace Engineering Theses - Archive

This work models the dynamic behavior of Estrogen docking into its receptor. It lays the foundation for the development of a new theoretical screening technique to identify carcinogens. It is predicted that this year, more than 1 million Americans and more than 10 million people worldwide will be diagnosed with cancer. Only 5 to 10 percent of all cancer cases can be attributed to genetic defects, whereas the remaining 90 to 95 percent have their roots in the environment. It has been suggested that some chemical compounds have a similar structure and properties as natural hormones produced by the human …

Utilization Of Microencapsulated Phase Change Material For The Optimization Of Evaporative Cooling Technology, Jeet Shah

Mechanical and Aerospace Engineering Theses - Archive

IT equipments are the essential facet of most institutional operations of the advanced world. Modern IT equipments are far more vigorous than older equipments. With increasing density of array of servers and growth of computing power, assessing the cooling requirements has emerged as an aspect of prime importance. Evaporative cooling is a very common cooling technology used in cooling of data centers due to low installation and power costs and simple operation. Phase change materials have been investigated over the years as thermal energy storage for cooling and heating applications. These researches have also investigated encapsulated PCM in different sizes …

Structural Analysis At Aircraft Conceptual Design Stage, Reza Mansouri

Mechanical and Aerospace Engineering Theses - Archive

In the past 50 years, computers have helped by augmenting human efforts with tremendous pace. The aircraft industry is not an exception. Aircraft industry is more than ever dependent on computing because of a high level of complexity and the increasing need for excellence to survive a highly competitive marketplace. Designers choose computers to perform almost every analysis task. But while doing so, existing effective, accurate and easy to use classical analytical methods are often forgotten, which can be very useful especially in the early phases of the aircraft design where concept generation and evaluation demands physical visibility of design …

Numerical Simulations Of Transonic Wingtip, Suparat Chanrith

Mechanical and Aerospace Engineering Theses - Archive

This report presents numerical simulations using ANSYS FLUENT for a NACA 0012 wing both in two- and three-dimensional cases to compare with an experimental data. This comparison also allowed for any wall interference in wind tunnels to be examined. Moreover, the report also presents numerical simulation of a NACA 0012 wingtip. The simulations were conducted at Mach 0.5, 0.7, 0.75, and 0.8 at various chord Reynolds number and the angle of attack of 0, 2, 4, and 5. The numerical andexperimental data were in good agreement for the full wing and the wingtip cases.

Experimental Study On The Effects Of Gaseous Contamination On It Equipment, Rahul Srinivas Raghunathan

Mechanical and Aerospace Engineering Theses - Archive

Every company is trying to reduce their carbon footprint in today's world. The data center industry is no different. To reduce the cooling costs and increase the efficiency, air -side economizers are used. Air-side economizers bring in outside ambient cold air to cool the data center equipment. Through this, we can save on cooling costs. The problem relating to air-side economization is that we have no control over the humidity and contamination. Humidity and contamination go hand in hand, as one influence the other. In the past filters have been used to combat contamination but it has proved to be …

Development Of Foil Thrust Bearing Test Rig, Rohit Harishchandra Yadav

Mechanical and Aerospace Engineering Theses - Archive

Oil lubricated bearings have been widely used in variety of turbo machinery, though it has its own limitations such as thermal degradation of oil over temperature, complicated oil lubrication system and their maintenance. Commercial application of the air foil bearing (AFB) in Microturbomachinery have been acknowledged. Microturbomachinery term is used in applications with shaft power less than 1000KW and shaft diameter less than 100mm. Microturbomachinery has demanded light weighted, compact, extreme temperature and high speed operation. DN number for oil lubricated bearings and rolling element bearings is very less when compared to foil bearings. Absence of external pressurizing and lubricating …

Point Measurement Of Detonation Wave Propagation Using Ion Guage, Nitesh Karpakala Manjunatha Gupta

Mechanical and Aerospace Engineering Theses - Archive

Accurate measurement of detonation wave velocity is important in the study of detonations. Detonation wave velocity is calculated by the ratio of distance between two transducers which the wave front travels over the propagation time. Conventional methods included transducers placed a few cm apart thereby yielding an average velocity of the wave. A gauge was developed in which the transducers were placed a few mm apart so that an effective point measurement of velocity can be determined. Different types of sensors used in determining the detonation wave velocity included pressure, flame and ion. Of the three, the ion sensor was …

Effect Of Nanoparticle Dispersions In A Binary Nitrate Salt As Thermal Energy Storage Material In Concentrated Solar Power Applications, Bharath Dudda

Mechanical and Aerospace Engineering Theses - Archive

Despite the huge improvements in the field of solar energy to produce electricity, the high cost of production has been one of the major problems in this field. Concentrated solar power (CSP) uses a number of mirrors to concentrate solar radiant energy onto a single focal point. Electrical power is produced when the concentrated light is converted to heat, which drives a heat engine connected to an electrical power generator. This heat is first stored in a thermal energy storage (TES) and transferred to a heat engine to be converted to electricity and thus TES can provide heat even after …

Utilization Of Molten Nitrate Salt Nanomaterials For Heat Capacity Enhancement In Solar Power Applications, Ramaprasath Devaradjane

Mechanical and Aerospace Engineering Theses - Archive

Concentrated solar power (CSP) system use general thermodynamic cycle to produce electricity and thus the system efficiency is mainly determined by the working temperature of heat transfer fluid (HTF). Organic-based HTFs (e.g., mineral oil, ethylene glycol, etc.) were firstly used for this application. However, this has limited the working temperature of CSP around 300 °C since these organic material starts to decompose below 400 °C. Typical liquid salts are thermally stable to high temperatures (500~600 °C). Using these salts as HTF can significantly increase the working temperature and as a result the system efficiency can also be highly enhanced. For …

Design And Analysis Of A Compression Molded Carbon Composite Wheel Center, Vinoth Kumar Dhananjayan

Mechanical and Aerospace Engineering Theses - Archive

Importance of closed mold and short fibers in the manufacture of carbon composite parts was realized based on a study of existing manufacturing processes for thermoset resins as these can improve production volumes, cost reduction of the part, production of near net shape parts eliminating secondary operations and production of parts with near isotropic properties due to random fiber orientation. Compression molding process is the most preferred process as this addresses the problems of fiber damage effectively because of the minimal flow in the material. A brief study was done on the compression molded carbon composite parts in the industry. …

Integrated Modeling Approach For Solid Oxide Fuel Cell-Based Power Generating System, Jeongpill Ki

Mechanical and Aerospace Engineering Dissertations - Archive

Solid oxide fuel cell (SOFC) systems have been recognized as the most advanced power generation system with the highest thermal efficiency with a compatibility with a wide variety of hydrocarbon fuels, synthetic gas from coal, hydrogen, etc. As a result of research focused on numerical studies for a tubular type- or a planar type-SOFC, fuel flexibility, design aspects of SOFC, materials, start-up process, and so on, SOFC technologies are remarkably being developed.Currently, most research activities are limited to a component level characterization of single fuel cell stack or material research for catalyst, electrolyte, sealing process, etc. In other words, approaches …