Mechanical Engineering Commons^™

Computational Analysis Of Nanostructures Formed In Molten Salt Nanofluids, Vidula B. Pawar

Mechanical and Aerospace Engineering Theses - Archive

Meeting the continuously increasing demand of `clean' energy is the biggest challenge of the energy research field. Amongst the many renewable sources of energy, energy from the Sun is one of the biggest sources in the form of light and heat. Photovoltaic cells and concentrated solar power are few of the solar energy harnessing technologies. Photovoltaic cells use semiconductor materials to directly convert energy from sun into electricity. CSP uses a combination of solar receivers (mirrors or lenses) to concentrate the solar thermal energy which is further converted into electricity using the common thermodynamic cycle. One of the Photovoltaic (PV) …

Computational Fluid Dynamics Simulation Of United Launch Alliance Delta Iv Hydrogen Plume Mitigation Strategies, Stephen Guimond

Electronic Theses and Dissertations

During the launch sequence of the United Launch Alliance Delta IV launch vehicle, large amounts of pure hydrogen are introduced into the launch table and ignited by Radial-Outward-Firing-Igniters (ROFIs). This ignition results in a significant flame, or plume, that rises upwards out of the launch table due to buoyancy. The presence of the plume causes increased and unwanted heat loads on the surface of the vehicle. A proposed solution is to add a series of fans and structures to the existing launch table configuration that are designed to inject ambient air in the immediate vicinity of the launch vehicle's nozzles …

Thermal Conductivity Of Alumina And Silica Nanofluids, Julian Bernal Castellanos

All Graduate Theses, Dissertations, and Other Capstone Projects

This thesis studies the effects of the base fluid, particle type/size, and volumetric concentration on the thermal conductivity of Alumina and Silica nanofluids. The effects of base fluid were observed by preparing samples using ethylene glycol (EG), water, and mixtures of EG/water as the base fluid and Al2O3 (10 nm) nanoparticles. The particles type/size and volumetric concentration effects were tested by preparing samples of nanofluids using Al2O3 (10nm), Al2O3 (150nm), SiO2 (15 nm), and SiO2 (80 nm) nanoparticles and ionized water as base fluid at different volumetric concentrations. All samples were mixed using a sonicator for 30 minutes and a …

Thermo-Mechanical Feasibility Study Of Copper And Gold Wirebonds In 3d Electronic Package, Gaurang Naware

Mechanical and Aerospace Engineering Theses - Archive

3 Dimensional (3D) Electronics Packaging has emerged as a revolutionary trend in the micro-electronics industry. It has made possible cost-effective system integration and size scaling while reducing the interconnect delay. The ever increasing demand for better mechanical, thermal, electrical performance, improved reliability and cost effective semiconductor manufacturing technology has encouraged the engineers to replace Gold (Au) by Copper (Cu). In a survey conducted by Semiconductor Equipment and Materials International, to study the industry mood related to wirebond technology, it was observed that 72% of the leading semiconductor companies are considering switching to Cu [1]. The only major concern regarding the …

Fabrication Of Superhydrophobic Polystyrene Surfaces With Tunable Adhesion By Modulating Strain Recovery Temperature, Prasha Sarwate

Mechanical and Aerospace Engineering Theses - Archive

In this work, different superhydrophobic structures were fabricated on the surfaces of polystyrene (PS) blocks, using oxygen reactive ion etch (ORIE) and controllable strain recovery. The PS used here is a thermal shape memory polymer (SMP). Microhills are first generated on the surface of a PS block by ORIE. The PS block is then heated up, which triggers the strain recovery. During this process of recovering its original shape, the PS block gradually reduces its lateral dimensions, while increasing its thickness. Using different recovery temperatures, the surface morphologies can be controlled, which provides an approach to adjust surface wetting properties, …

Electric Vehicle Sales And Future Projections, Florida Solar Energy Center, David L. Block

FSEC Energy Research Center®

The objective of this research is to evaluate historical vehicle sales as a basis to determine future projections of electric vehicles sales and cumulative values within the U.S. and by selected states. The results for the U.S. show that the cumulative sales of electric vehicles through 2013 is 167,600 vehicles with 96, 700 sold in 2013 or that 58% of total vehicles were sold in 2013. Depending upon the escalation rate selected, the 10 year future U.S. cumulative sales (2023) are predicted to be from 1.8 to 7.3 million vehicles. Future predictions were also done for the states of Florida, …

Piezospectroscopic Calibration Of Alumina-Nanocomposites For The Development Of Stress-Sensing Structures, Daniela Fugon-Dessources

Electronic Theses and Dissertations

Alpha-alumina is known to exhibit photo-luminescent (PL) properties, mainly characteristic R-lines that shift according to applied stress. In addition to showing excellent PL properties, polymers with embedded alumina nanoparticles have been shown to improve the overall composite mechanical properties. While the use of the PL properties to develop stress-sensing materials using an alumina-epoxy material has been success- fully shown in compression, the properties have not been developed for tension. In this study, the PL response of variable volume fraction alumina-epoxy composites will be determined under tensile conditions. It is expected that increasing the volume fraction of alumina nanoparticles will increase …

Response Of Electrified Micro-Jets To Electrohydrodynamic Perturbations, Weiwei Yang

Electronic Theses and Dissertations

The breakup of liquid jets is ubiquitous with rich underpinning physics and widespread applications. The natural breakup of liquid jets originates from small ambient perturbations, which can grow exponentially until the amplitude as large as the jet radius is reached. For unelectrified inviscid jets, surface energy analysis shows that only the axisymmetric perturbation is possibly unstable, and this mode is referred as varicose instability. For electrified jets, the presence of surface charge enables additional unstable modes, among which the most common one is the whipping (or kink) instability that bends and stretches the charged jet that is responsible for the …

A Study Of Compressive Sensing For Application To Structural Health Monitoring, Vaahini Ganesan

Electronic Theses and Dissertations

One of the key areas that have attracted attention in the construction industry today is Structural Health Monitoring, more commonly known as SHM. It is a concept developed to monitor the quality and longevity of various engineering structures. The incorporation of such a system would help to continuously track health of the structure, indicate the occurrence/presence of any damage in real time and give us an idea of the number of useful years for the same. Being a recently conceived idea, the state of the art technique in the field is straight forward - populating a given structure with sensors …

Mechanical And Thermal Characterization Of Continuous Fiber-Reinforced Pyrolysis-Derived Carbon-Matrix Composites, Donovan Lui

Electronic Theses and Dissertations

Maturity of high-temperature polymer-reinforced composites defer to conventionally expensive and intensive methods in both material and manufacturing aspects. Even traditional carbon-carbon, aerogel, and ceramic approaches are highly limited by difficult manufacturing techniques and are subject to sensitive handling throughout their processing and lifetime. Despite their utility in extreme environments, the high costs of existing high-temperature composites find limited practical applicability under high-performance applications. The development of continuous fiber-reinforced pyrolysis-derived carbon-matrix composites aim to circumvent the issues surrounding the manufacturing and handling of conventional high-temperature composites. Polymer matrix composites (PMCs) have a number of attractive properties including light weight, high stiffness-to-weight …

Assessment Of Corn Stover Torrefaction For On-Farm Biochar Production, Christina M. Gerometta

Electronic Theses and Dissertations

Torrefaction is a thermochemical pretreatment process that is typically achieved by slowly heating biomass (<50°C/min) within the temperature range of 200 – 300°C under an inert atmosphere. This process yields a storable solid product with enhanced fuel characteristics that are influenced by the ligno-cellulosic composition of the original feedstock and the imposed torrefaction conditions (time and temperature). This study is an assessment of corn stover properties that are relevant for designing an on-farm torrefaction system. The first portion of this study compared the thermal decomposition behaviors of corn stover fractions (leaf, stalk, cob) to the respective ligno-cellulosic composition using thermo-gravimetric analysis. It was found that the thermal decomposition pattern correlates to the structure and ratio of ligno-cellulosic polymers and provides design guidelines for an on-farm torrefaction system capable of handling large quantities of mixed fraction stover. The second part of this study investigated the effects of torrefaction time and temperature on the mass and energy yield of mixed fraction corn stover using a 46.3 L batch style reactor. It was found that longer reaction times and higher temperatures were required to obtain mass and energy yields similar to those found using lab-scale reactors and finely milled samples. Non-uniform torrefaction occurred between fractions due to chemical composition of each fraction and proximity to the heating elements.

Using Acoustic Emission Monitoring For Energy-Based Fatigue Life Prediction, Sepehr Nesaei

Electronic Theses and Dissertations

The study of fatigue and fracture mechanics is crucial to the health monitoring and overall safety of aerospace and civil structures. The materials used to manufacture these industry parts have inherent anomalies that eventually grow under cyclic loadings during regular operation. The ASTM and/or military testing guidelines used to analyze and qualify structures and materials for use are costly and time consuming. Therefore, any additional methods or knowledge that can be used to reduce the number of tests will be useful to the industry to avoid unnecessary costs. Acoustic emission (AE) monitoring is currently used in many applications to assess …

Semiactive Virtual Control Method For Robots With Regenerative Energy-Storing Joints, Hanz Richter, Daniel J. Simon, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

A framework for modeling and control is introduced for robotic manipulators with a number of energetically self-contained semiactive joints. The control approach consists of three steps. First, a virtual control design is conducted by any suitable means, assuming a fully-actuated system. Then, virtual control inputs are matched by a parameter modulation law. Finally, the storage dynamics are shaped using design parameters. Storage dynamics coincide with the system's internal dynamics under exact virtual control matching. An internal energy balance equation and associated self-powered operation condition are given for the semiactive joints. This condition is a structural characteristic of the system and …

Dynamic Fracture Analysis Of Polycarbonate By The Optical Method Of Caustics, Guiyun Gao, Zheng Li, Mehrdad Negahban

Department of Mechanical and Materials Engineering: Faculty Publications

Glassy polycarbonate (PC) is a widely used engineering material in industries, since it has high strength and toughness as well as good transparency. However, these advantages of PC can be suppressed by physical aging, especially its dynamic fracture toughness. In addition, the material properties of PC can be changed dramatically after large plastic compressive deformation, and it can show obvious orthotropic behavior. Here, the combined effect of aging and plastic compressive deformation on dynamic facture of PC was investigated by the optical method of caustics. The dynamic reflective method of caustics for orthotropic materials was developed here to study the …

Performance Evaluation Of Polyurethane Composites Using Vacuum Infusion Process, Mohaned M. Mohamed

Doctoral Dissertations

"Glass fiber-reinforced polymer composites have promising applications in infrastructures due to their low cost, high specific stiffness/strength, and corrosion resistance. The pultrusion process is often used to manufacture glass fiber-reinforced polyurethane (PU) composite. The objective of this study is to use thermoset PU resin to manufacture high quality composites for infrastructure applications using vacuum assisted resin transfer molding (VARTM) process. Using VARTM to fabricate PU resins presents unique challenges. Several modifications however have helped with overcoming these problems. In part I of the research, the mechanical performance of two different PU resin not only evaluated but also compared to one …

Modeling And Simulation Of Hydrokinetic Composite Turbine System, Haifeng Li

Doctoral Dissertations

"The utilization of kinetic energy from the river is promising as an attractive alternative to other available renewable energy resources. Hydrokinetic turbine systems are advantageous over traditional dam based hydropower systems due to "zero-head" and mobility. The objective of this study is to design and analyze hydrokinetic composite turbine system in operation. Fatigue study and structural optimization of composite turbine blades were conducted. System level performance of the composite hydrokinetic turbine was evaluated. A fully-coupled blade element momentum-finite element method algorithm has been developed to compute the stress response of the turbine blade subjected to hydrodynamic and buoyancy loadings during …

Integration Of A Pulsating Heat Pipe In A Flat Plate Heat Sink, Mitchell Hoesing

The Journal of Undergraduate Research

The ongoing development of faster and smaller electronic components has led to a need for new technologies to effectively dissipate waste thermal energy. The pulsating heat pipe (PHP) shows potential to meet this need, due to its high heat flux capacity, simplicity, and low cost. A flat plate PHP was integrated into an aluminum flat plate heat sink with a simulated electronic load. The PHP heat sink used water as the working fluid and had 20 parallel channels with dimensions 2 mm × 2 mm × 119 mm. Experiments were run under various operating conditions, and the thermal resistance of …

Vibrations Analysis On Tennis Racket String, Jenny Blackburne

The Journal of Undergraduate Research

The purpose of this project was to investigate and analyse the vibration of a tennis racket string when a ball is hit. This was done using concepts of mechanical vibrations and modelled using Microsoft Excel. The displacement of the tennis string over time was graphed for two different positions on the racket and two different relative speeds of the tennis ball. It was found that the position of the tennis ball on the racket has very little effect on the displacement of the strings. If the ball or racket is moving faster when the ball is hit, then the displacement …

Ambulatory Extracorporeal Arterioveous Co2 Removal Via Subclavian Vessels, Alejandra Macias, Alvaro Rojas-Pena

McNair Poster Presentations

Lung transplantation is the last recourse for patients with severe respiratory failure. However, transplantable lungs do not keep up with the demand, and 15.4% of patients die awaiting transplant. An alternative therapy is extracorporeal life support (ECLS), which uses a pump and an oxygenator to serve as a bridge to transplant. However, this technology limits ambulation and requires ICU care. This novel study implements pumpless arteriovenous (AV) ECLS technology to remove CO2 via the subclavian vessels, providing respiratory support and hypercapnia (excessive CO2 retention) sympton relief for patients while allowing ambulation.

Computational Investigation Of Rotary Engine Homogeneous Charge Compression Ignition Feasibility, Michael Irvin Resor

Browse all Theses and Dissertations

The Air Force Research Laboratory (AFRL) has been investigating the heavy fuel conversion of small scale Unmanned Aerial Vehicles (UAV). One particular platform is the Army Shadow 200, powered by a UEL Wankel rotary engine. The rotary engine historically is a proven multi-fuel capable engine when operating on spark ignition however, little research into advanced more efficient compression concepts have been investigated. A computational fluid dynamics model has been created to investigate the feasibility of a Homogeneous Charge Compression Ignition (HCCI) rotary engine. This research evaluates the effects, rotor radius to crankshaft eccentricity ratio, known as K factor, equivalence ratio, …

Active Infrared Sensing Of Impact Damage In Carbon Fibre Reinforced Polymer, Kwek Tze Tan, Liping Zhao, Shaochun Ye, Tong Kuan Chuah, Pramoda Kumari Pallathadka, Hui Ru Tan

Mechanical Engineering Faculty Research

With the growing demand of carbon fibre reinforced plastic (CFRP) in aerospace, marine and automobile industries, much attention is devoted to characterizing the material strength and characteristics of failure. This paper demonstrated the feasibility to estimate the internal damage non-destructively as a result of a quantified impact applied on 16-ply fabric CFRP. On thermography images at different heating time, differences were observed between intact area and area with internal damage. The estimation of 1D extent of damage using thermographic analysis was compared with images observed with cross sectional microscopic. The results suggest that qualitative analysis using thermography shows potential to …

Electromyogram Synergy Control Of A Dexterous Artificial Hand To Unscrew And Screw Objects, Benjamin A. Kent, Nareen Karnati, Erik D. Engeberg

Mechanical Engineering Faculty Research

Due to their limited dexterity, it is currently not possible to use a commercially available prosthetic hand to unscrew or screw objects without using elbow and shoulder movements. For these tasks, prosthetic hands function like a wrench, which is unnatural and limits their use in tight working environments. Results from timed rotational tasks with human subjects demonstrate the clinical need for increased dexterity of prosthetic hands, and a clinically viable solution to this problem is presented for an anthropomorphic artificial hand.

The Mechanics Of Momentum Transfer From Explosive Charges Buried In Water, In Sand, And In Sand With Fines, David M. Fox

Wayne State University Dissertations

Physical tests involving full-scale systems subjected to blast loads are expensive. The development of more accurate computational and analytical methods to better understand and predict the mechanics of mine blast phenomena could be used to reduce the cost of development of mine protected vehicles and protective equipment for personnel involved in demining and similar activities.

Although the science associated with air blast and blast-related ground shock phenomena is very extensive, that of mine blast, involving explosives buried in soil, is less well developed. In this work, theoretical, experimental, and computational methods are synthesized to better understand some of the mechanisms …

Simulations And Measurements Of Fuel Film Using Refractive Index Matching Method, Fengkun Wang

Wayne State University Theses

ABSTRACT

SIMULATIONS AND MEASUREMENTS OF FUEL FILM USING REFRACTIVE INDEX MATCHING METHOD

by

FENGKUN WANG

APRIL 2014

Advisor: Dr. Ming-Chia Lai

Major: Mechanical Engineering

Degree: Master of Science

Direct Injection (DI) has been known for its improved performance and efficiency in gasoline spark-ignition engines. However, wall wetting is inevitable and the source of UHC and PM. In order to take advantage of the GDI technology, it is important to investigate spray wall interactions in detail.

Numerical and experimental studies are carried out for spray and wall impingements in an optical constant volume vessel. The fuel film was measured spatially and …

Assembly Of Bifurcation And Trifurcation Bipolar Plate To Design Fuel Cell Stack, Susanta K. Das, Jayesh Kavathe, Kingsley Joel Berry

Mechanical Engineering Patents

A current producing cell has anode flow plates 22 and cathode flow plates 20. Each of the flow plates 20, 22 defines a membrane face 26, a collector face 24, and a center axis C perpendicular to the membrane face 26 and the collector face 24. Each of the collector faces 24 define a plurality of cooling channels 74, 76, 78 and a plurality of transport channels 62, 64. The cooling channels 74, 76, 78 of the cathode flow plates 20 extend radially relative to the center axis C thereof to overlap the transport channels 62, 64 of the anode …

Biomechanical Performance Of Variable And Fixed Angle Locked Volar Plates For The Dorsally Comminuted Distal Radius, Patrick Atkinson, D. Martineau, J. Shorez, C. Beran, A. G. Dass

Mechanical Engineering Publications

Background

The ideal treatment strategy for the dorsally comminuted distal radius fracture continues to evolve. Newer plate designs allow for variable axis screw placement while maintaining the advantages of locked technology. The purpose of this study is to compare the biomechanical properties of one variable axis plate with two traditional locked constructs.

Methods

Simulated fractures were created via a distal 1 cm dorsal wedge osteotomy in radius bone analogs. The analogs were of low stiffness and rigidity to create a worst-case strength condition for the subject radius plates. This fracture-gap model was fixated using one of three different locked volar …

Qualifying Composition Dependent P And N Self-Doping In Ch3Nh3Pbi3, Qi Wang, Yuchuan Shao, Haipeng Xie, Lu Lyu, Xiaoliang Liu, Yongli Gao, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

We report the observation of self-doping in perovskite. CH₃NH₃PbI₃ was found to be either n- or p-doped by changing the ratio of methylammonium halide (MAI) and lead iodine (PbI₂) which are the two precursors for perovskite formation. MAI-rich and PbI₂-rich perovskite films are p and n self-doped, respectively. Thermal annealing can convert the p-type perovskite to n-type by removing MAI. The carrier concentration varied as much as six orders of magnitude. A clear correlation between doping level and device performance was also observed.

Experimental Validation Of A Robust Surge Speed Controller For Marine Surface Vessels, John Foehr

Wayne State University Theses

The focus of the current work is on providing experimental validation for the robust performance and good tracking characteristic of a surge speed controller for autonomous piloting of an under-actuated 16 ft boat in the completely uncontrolled setting of open-water Lake Saint Clair, Michigan. The controller is designed based on the sliding mode methodology and completely ignores the dynamics of the marine surface vessel (MSV) in its formulation. The testing was conducted under considerable unstructured uncertainties and unpredictable environmental disturbances induced by waves, sea-currents, and wind. The experimental results serve to validate the robust tracking characteristic of the controller and …

Test 2099: John Deere 8270r, 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 …

A Comparative Analysis Of Spatial Visualization Ability And Drafting Models For Industrial And Technology Education Students, Petros Katsioloudis, Vukica Jovanović, Mildred Jones

Engineering Technology Faculty Publications

The article presents the comparative study on the drafting models and spatial visualization ability of industrial and technology education students in the U.S. It discusses how the study was conducted which examined the issue based on technical drawings and with regards to the impacts of model types. The results reportedly revealed three-dimensional models are effective for promoting learning, however more studies have to be conducted.