Mechanical Engineering Commons^™

Incorporation Of Higher Carbon Number Alcohols In Gasoline Blends For Application In Spark-Ignition Engines, Kristina Lawyer

Dissertations, Master's Theses and Master's Reports

The 2007 U.S. Renewable Fuel Standard (RFS2) requires an increase in the use of advanced biofuels up to 36 billion gallons by 2022. Higher carbon number alcohols, in addition to cellulosic ethanol and synthetic biofuels, could be used to meet this demand while adhering to the RFS2 corn-based ethanol limitation. Alcohols of carbon numbers 2 through 8 are chosen based on their chemical and engine-related properties.

Blend comparison metrics are developed from automotive industry trends, consumer expectations, U.S. fuel legislation, and engine requirements. The metrics are then used to create scenarios by which to compare higher alcohol fuel blends to …

Model-Based Control Of Hybrid Electric Powertrains Integrated With Low Temperature Combustion Engines, Ali Soloukmofrad

Dissertations, Master's Theses and Master's Reports

Powertrain electrification including hybridizing advanced combustion engines is a viable cost-effective solution to improve fuel economy of vehicles. This will provide opportunity for narrow-range high-efficiency combustion regimes to be able to operate and consequently improve vehicle’s fuel conversion efficiency, compared to conventional hybrid electric vehicles (HEV)s. Low temperature combustion (LTC) engines offer the highest peak brake thermal efficiency reported in literature, but these engines have narrow operating range. In addition, LTC engines have ultra-low soot and nitrogen oxides (NOx) emissions, compared to conventional compression ignition and spark ignition (SI) engines. This dissertation concentrates on integrating the LTC engines (i) in …

Computational Studies On Biomechanics Of Concussion And On Efficacy Of Football Helmets, David Labyak

Dissertations, Master's Theses and Master's Reports

Football helmets have been used for many years to prevent head injuries to players. Over the years, the helmet design has evolved from a crude leather head covering to the more recent form fitting helmets that are seen today. The one design feature that has been common in the majority of all helmets is a hard polycarbonate shell with a foam cushion padding. The main goal of the padding layer was to reduce the amount of linear acceleration during an impact event. The one feature that has been overlooked is how stiff the padding is in rotation.

The purpose of …

Utilizing Reprap Style 3d Printers For The Manufacturing Of Composite Heat Exchangers, John Laureto

Dissertations, Master's Theses and Master's Reports

The low cost 3D printing market is currently dominated by the application of RepRap (self-replicating rapid-prototyper) variants. Presented in this document are practical utilizations of RepRap technology. Developed are innovative processes to manufacture composite materials systems for thermal management solutions.

First, a laser polymer welder system is validated by quantifying maximum peak load and weld width of linear low density polyethylene (LLDPE) lap welds as a function of linear energy density. The development of practical engineering data, in this application, is critical to producing mechanically durable welds. Developed laser and printer parameter sets allow for manufacturing of LLDPE multi-layered heat …

A Study Of High Temperature Heat Pipes And The Impact Of Magnetic Field On The Flow Of Liquid Metal, Udit Sharma

Dissertations, Master's Theses and Master's Reports

A study of high temperature heat pipe was conducted to understand its characteristics. A review of working fluid, temperature, wick structure, problems, operational limit and applications was done. Alkali metal were concluded as the most viable candidate for the working fluid.

The impact of three parameters namely magnetic field, heat flux and temperature was analyzed on the performance of HTHP (High Temperature Heat Pipe). The presence of magnetic field had the most considerable impact on reducing the pumping limit of the heat pipe while the temperature had almost negligible effect. Magnetic field results in the pressure drop and adversely affect …

Analysis Of Aeroelastic Effects On The 3-Dimensional Interference Of Wind-Turbine Rotors, Anurag Rajan

Dissertations, Master's Theses and Master's Reports

Greater penetration of wind energy demands better utilization of available wind. This has led to a formidable increase in the rotor diameter over the past few years. Bigger rotors call for lighter, more flexible blades to reduce loads and improve fatigue life. As a result, future blades will deform substantially more than the relatively stiff blades of the past. More efficient use of wind power also calls for incorporating advanced active and passive control strategies and increasing the range of velocities over which wind energy is captured. Hence an improvement in the quality of numerical simulations capable of capturing the …

Control Of A Powered Ankle-Foot Prosthesis: From Perception To Impedance Modulation, Guilherme Aramizo Ribeiro

Dissertations, Master's Theses and Master's Reports

Active ankle prostheses controllers are demonstrating gaining smart features to improve the safety and comfort offor users. The perception of user intention to modulate the ankle dynamics is a well-known example of such feature. But not much work focused on the perception of the environment, nor how the environment should be included in the mechanical design and control of the prosthesisprostheses. The proposed work aims to improve the feasibility of integrate the environment perception integration intoto the prostheses controllersler, and to define the desired ankle dynamics, as mechanical impedance, duringof the human walk on different environmental settings. As a preliminary …

Model-Based Control Of An Rcci Engine, Akshat Abhay Raut

Dissertations, Master's Theses and Master's Reports

Reactivity controlled compression ignition (RCCI) is a combustion strategy that offers high fuel conversion efficiency and near zero emissions of NOx and soot which can help in improving fuel economy in mobile and stationary internal combustion engine (ICE) applications and at the same time lower engine-out emissions. One of the main challenges associated with RCCI combustion is the difficulty in simultaneously controlling combustion phasing, engine load, and cyclic variability during transient engine operations.

This thesis focuses on developing model based controllers for cycle-to-cycle combustion phasing and load control during transient operations. A control oriented model (COM) is developed by using …

Multiscale Modeling: Thermal Conductivity Of Graphene/Cycloaliphatic Epoxy Composites, Sorayot Chinkanjanarot

Dissertations, Master's Theses and Master's Reports

The thermal property of epoxy as the binder in the Carbon Fiber (CF) composites, especially thermal conductivity is important to achieve the advance technology and to improve the performance of materials. Multiscale modeling including molecular dynamic (MD) modeling and micromechanical modeling is used to study the properties of neat Cycloaliphatic Epoxies (CE) and Graphene nanoplatelet (GNP)/CE with and without covalent functionalization.

The thermal properties (glass-transition temperature, thermal expansion coefficient, and thermal conductivity) and mechanical properties of CE system are investigated by MD modeling using OPLS-All Atom force field. A unique crosslinking technique is developed to achieve the cured CE models …

Modeling Mass And Thermal Transport In Thin Porous Media Of Pem Fuel Cells, Vinaykumar Konduru

Dissertations, Master's Theses and Master's Reports

Water transport in the Porous Transport Layer (PTL) plays an important role in the efficient operation of polymer electrolyte membrane fuel cells (PEMFC). Excessive water content as well as dry operating conditions are unfavorable for efficient and reliable operation of the fuel cell. The effect of thermal conductivity and porosity on water management are investigated by simulating two-phase ow in the PTL of the fuel cell using a network model. In the model, the PTL consists of a pore-phase and a solid-phase. Different models of the PTLs are generated using independent Weibull distributions for the pore-phase and the solid-phase. The …

Development Of An Evaporation Sub-Model And Simulation Of Multiple Droplet Impingement In Volume Of Fluid Method, Sathya Prasad Potham

Dissertations, Master's Theses and Master's Reports

Droplet collision and impingement on a substrate are widely observed phenomenon in many applications like spray injection of Internal Combustion Engines. Existing Lagrangian models do not provide a comprehensive picture of the outcome of these events and may involve model constants requiring experimental data for validation. Physics based models like Volume of Fluid (VOF) method involve no parametric tuning and are more accurate. The aim of this thesis is to extend the basic VOF method with an evaporation sub-model including an additional vapor phase and implement this model in an open source Computational Fluid Dynamics (CFD) software, OpenFOAM. The new …

Assessment Of Annular Flow Boiling In The Context Of Computational Fluid Dynamics (Cfd) Simulations, Experiments, And Existing Correlations, Hrishikesh Prasad Ranga Prasad

Dissertations, Master's Theses and Master's Reports

The main objective of the current work is to achieve a better understanding – through modeling and simulation/programming activities – of annular flow-boiling and its applications based on a synthesis of Computational Fluid Dynamics (CFD) simulations, existing correlations, and experiments. A unique and rigorous 2-D CFD simulations technique was developed for annular flow-boiling to propose a correlation for convective component of Heat Transfer Coefficient (HTC) – defined here as flow-boiling in the absence of nucleation. To provide a context for the correlation structure of convective component of HTC, flow-physics details of annular flow-boiling and correlation structure (based on fundamental considerations) …

The Impact Of Water Injection On Spark Ignition Engine Performance Under High Load Operation, Jeremy Worm

Dissertations, Master's Theses and Master's Reports

An experimental effort has been completed in which water injection was investigated as a means of enabling increases in engine output and high load efficiency. Water was injected into the intake port of a direct fuel injected, 4-cylinder, boosted engine with dual independent variable valve timing. The water was shown to increase volumetric efficiency and decrease the onset of knock which in turn enable more optimal combustion phasing. Both of these affects resulted increases in load of up to 5.5% at the same manifold pressure as the baseline case. The advancement of combustion phasing, combined with elimination of fuel enrichment …

Influence Of Magnetic Nanoparticles And Magnetic Stress On An Ionic Liquid Electrospray Source, Kurt Joseph Terhune

Dissertations, Master's Theses and Master's Reports

Two electrospray sources were developed to operate on an ionic liquid ferrofluid; one source was a pressure‑fed capillary electrospray source and the other was a novel electrospray source which used a magnetically‑induced instability to produce a peak from which an electric field could extract electrospray. Multiple characteristics of electrospray operation were examined for both sources using faraday plates/cups, a quartz crystal microbalance, a retarding potential analyzer, and a time-of-flight mass spectrometer. The ILFF electrosprays for a capillary source were shown to operate in a mixed ion/droplet regime. The mass flow of the electrospray beam was primarily transported by larger particles …

Heat Transfer Analysis In A Paddle Reactor For Biomass Fast Pyrolyis, Ankith Ullal

Dissertations, Master's Theses and Master's Reports

Heat transfer analysis was performed on a novel auger reactor for biomass fast pyrolysis. As part of this analysis, correlations for specific heat capacity and heat transfer coefficients for biomass (sawdust) and sand (used as heat transfer medium) were developed. For sand, the heat transfer coefficient followed a power law distribution with reactor fill level and temperature. For raw biomass, the heat transfer coefficient also showed similar dependence on fill level, but was independent of temperature up to 300°C. These correlations were used in a one dimensional heat transfer model developed to calculate the heating time and heating rate of …

Fea Analysis And Optimization Of Differential Housing For Fatigue Stresses And Fatigue Test Design To Study Skin Effect In Ductile Iron, Swapnil A. Pandey

Dissertations, Master's Theses and Master's Reports

Automotive emission standards are getting more stringent day by day and governments worldwide are moving to reduce emissions from automobiles. In this scenario reducing the weight of automobile components becomes an important design objective to reduce emissions. A 10% reduction of weight in the complete automobile leads to 6-8 percent improvement in mileage (Mhapankar 2015). Also, powertrain components make up for approximately 27% of the total automobile weight and thus optimizing the design of components in the powertrain is an important task (Mhapankar 2015). Statistics show that 26% of component failures in automobiles are part of powertrain and 21% of …

A 3 D- Fem Study On The Stress Distributions In Pediatric Skull Due To Impact From Free Fall, Suryanshu Walvekar

Dissertations, Master's Theses and Master's Reports

Abstract

Brain is vulnerable to injuries even from low heights of fall. There are many infant casualties who get severe brain injury each year. This research is a simulated study of the stress patterns and values when human infant skull is subjected to free fall. The input velocity was calculated using simple free fall velocity formulas and was fed into the simulation. Model was meshed and refined using Hypermesh software. RADIOSS solver of the Hyperworks package was used to analyze and draw results for the simulation process. Various types of stresses and strains were extracted and plotted against respective drop …

A 3d Fem Comparative Study On The Impact Response Between Human Head And Nocsae Head Due To Free Fall, Amey S. Badhe

Dissertations, Master's Theses and Master's Reports

We all enjoy sports be it watching or playing. Concussion is well known topic when it comes sports related injuries. However, concussion and brain injury is not exclusive to sports and outdoor activities. Sometimes, even the impact due to slip and fall at small heights can cause serious damage to the head and brain. This report studies the response generated in the human head model and the commercially use dummy NOCSAE headform due to drop from height of 2, 3, 4 and 5 feet. Earlier studies have related brain kinetics and head kinematics to concussion and traumatic brain injury (TBI). …

Investigation Of The Use Of 3-D Printer Platform As Building Block For Rapid Design Of Research And Manufacturing Tool, Handy Chandra

Dissertations, Master's Theses and Master's Reports

This thesis attempts to show how an open source 3-D printer platform, the self replicating rapid prototype (RepRap), could be used to accelerate the development of research and manufacturing tools. Two projects are shown as examples, both utilizing components of the 3-D printer platform.

The first project is to develop an instrument capable of performing automated large-area four-point probe measurements. A modified RepRap 3-D Printer with a four-point probe in place of the 3-D printer head is utilized as a precision positioning platform. The printer together with custom designed measurement circuit and software performs automated measurement on multiple points on …

Frontal Crash Analysis Of A Conformable Cng Tank Using Finite Element Analysis, Datta Sandesh Manjunath

Dissertations, Master's Theses and Master's Reports

The purpose of this study is to computationally model and analyze a Conformable Compressed Natural Gas (CNG) fuel tank for frontal crashes using Finite Element Analysis. Researchers have developed a CNG fuel tank, which is conformable, non-conventional and non-cylindrical. This tank increases cost efficiency, volumetric efficiency and cargo efficiency in CNG vehicle applications. A lightweight pickup truck (2015 Chevrolet Silverado) has been used to integrate the CNG tanks and field-testing has been conducted to demonstrate the application.

The report mainly focuses on the effective finite element modeling of the chassis, brackets and tanks using HYPERMESH and RADIOSS. The frontal crash …

Impact Of E20 Fuel On A High-Performance, Two-Stroke Engine, Jon Gregory Loesche

Dissertations, Master's Theses and Master's Reports

The purpose of this project was to explore the emissions, combustion, and performance effects of running a gasoline/ethanol fuel mixture of 20 percent by volume (E20) in a fuel-injected, two-stroke engine. The engine was operated at five engine speeds that corresponded with the EPA 5-mode emissions test for snowmobile engines. Single parameter sweeps were conducted along with a preliminary recalibration of the test engine at two E0 target values (lambda and mid-pipe temperature) using E20 fuel.

Baseline testing showed that running E20 fuel produced a leaner air/fuel mixture compared to E0, resulting in higher lambda values for all modes and …

Minimizing Run Time Of Finite Element Analyses: Applications In Conformable Cng Tank Modeling, Paul M. Roehm

Dissertations, Master's Theses and Master's Reports

REL Inc. has proposed a CNG tank that deviates from typical cylindrical storage methods. The goal of REL working with Michigan Tech is to minimize mass and meet NGV2 safety standards for pressure and drop testing for this tank.

The model has undulated outer surfaces and Schwarz P-surface internal geometry. To accurately mesh this, a small element size is necessary; this creates a model with millions of elements. In explicit analyses, this requires a large amount of computational resources to run.

This report focuses on methods to reduce model run time without reducing accuracy. Methods covered include creating symmetric building …

Advanced Uses For Carbon Nanotubes: A Spherical Sound Source And Hot-Films As Microphones, Micaela M. Thiery

Dissertations, Master's Theses and Master's Reports

Super-aligned carbon nanotube (CNT) thin-film is used to create thermophones. The thermal properties of CNT film allow it to rapidly heat and cool when supplied AC power producing temperature and pressure gradients and, therefore, audible sound. The advantages of CNT thermophones include eliminating all moving components of traditional speakers and reducing the weight of the speaker itself by using CNT film, which is nearly weightless. Additionally, the flexibility of CNT film provides the unique opportunity to construct loudspeakers of various sizes and geometries. In this work, a spherical CNT thermophone is designed, manufactured, and tested for directivity with the overall …

Development Of A High-Fidelity Model And Kalman Filter Based State Estimator For Simulation And Control Of Nox Reduction Performance Of A Scr Catalyst On A Dpf, Venkata Rajesh Chundru

Dissertations, Master's Theses and Master's Reports

Reduction of emissions and improving the fuel consumption are two prime research areas in Diesel engine development. The present after-treatment systems being used for emissions control include diesel oxidation catalyst (DOC) for NO, HC and CO oxidation along with catalyzed particulate filters for PM (particulate matter) and selective catalytic reduction (SCR) for controlling NOx emissions. Recently an after-treatment system called SCR catalyst on a DPF capable of simultaneously reducing both NOx and PM emissions has been developed in order to reduce the overall size of the after-treatment system.

The goal of this proposed research is to create a state estimator …

Simulation Of Human Ankle Trajectory During Stance Phase Of Gait, Leslie Castelino

Dissertations, Master's Theses and Master's Reports

A simulation was developed which mimics the human gait characteristics based on the input of an individual’s gait trajectory. This simulation also estimates the impedance of the human ankle based on the ground reaction forces measured by the force plate. This simulation will accept alterations of the following parameters: total body weight, weight of the shank, weight of the foot, trajectories of the shank and foot of the individual and orientation of the force plate, which would generate a new gait trajectory for the ankle during the stance phase of gait. The goal of this simulation was to validate the …

Performance Of Hard Disk Drives In High Noise Environments, Trinoy Dutta

Dissertations, Master's Theses and Master's Reports

Digital information stored in rotational media, such as Hard Disk Drives (HDD) needs to be reliable and readily accessible. Various studies have been performed on the modal analysis of HDDs and the noise emitted during operation. Analysis performed by Siemens Corporation, IBM and Tyco Fire Protection Products show that HDDs are sensitive to noise. This report initially focusses on identifying the critical frequency ranges and the levels of noise where the performance of the drives reduces. A series of tests have been performed using pink noise at one-third octave frequency bands at sound pressure levels ranging from 80 dB to …

Simulation Study On Effect Of Gas Charging And Egr In A Dual-Fuel Engine, Satyavenkata Naga Sai Sharath Gorthy

Dissertations, Master's Theses and Master's Reports

Natural gas combined with diesel as micro pilot has the capabilities of achieving lower NOx and soot emissions. Optimization of the combustion process in engines with natural gas and diesel micro-pilot is essential to achieve higher efficiencies and loads. Gas charging (intake air boosting) and EGR are two technologies which when implemented in the natural gas-diesel engines, provide the opportunity to achieve higher efficiencies and loads and low emissions. Simulation study is one of the approaches to investigate the extent and effects of gas charging and EGR on the performance of the engine. With the rapid improvements over the past …

Human Centered Design Of An Open-Drum, Treadle Thresher For Quinoa Farmers In The Andes Of Northern Peru, Robert A. Hayes

Dissertations, Master's Theses and Master's Reports

Growing international demand for quinoa in recent years has led to increased production throughout its South American range, including the Peruvian Andes. Small-scale farmers, who are among the poorest Peruvians, are increasingly growing quinoa for both food security and economic benefit; however, manual harvesting activities, such as threshing, are labor-intensive and time-consuming. This report documents the design, construction and operation of prototype quinoa thresher in a rural village in Northern Peru. In addition, an overview of the history and evolutionary approach to design for the developing world is presented. From this overview, a series of criteria is considered for the …

Using Lower Extremity Muscle Activations To Estimate Human Ankle Impedance In The External-Internal Direction, Lauren N. Knop

Dissertations, Master's Theses and Master's Reports

For millions of people, mobility has been afflicted by lower limb amputation. Lower extremity prostheses have been used to improve the mobility of an amputee; however, they often require additional compensation from other joints and do not allow for natural maneuverability. To improve upon the functionality of ankle-foot prostheses, it is necessary to understand the role of different muscle activations in the modulation of mechanical impedance of a healthy human ankle. This report presents the results of using artificial neural networks (ANN) to determine the functional relationship between lower extremity electromyography (EMG) signals and ankle impedance in the transverse plane. …

Multi-Modal And Short-Range Transmission Loss In Ice-Covered, Near-Shore Arctic Waters, Miles B. Penhale

Dissertations, Master's Theses and Master's Reports

In the past century, extensive research has been done regarding the sound propagation in arctic ice sheets. The majority of this research has focused on low frequency propagation over long distances. One of the most commonly used excitation methods for air-ice-water layers has been explosives. However, environmental regulation has become more stringent, disallowing the use of almost all explosive excitation types. Due to changing climate conditions in these environments, new experimentation is warranted to determine sound propagation characteristics in, through, and under thin ice sheets, in shallow water, over short distances. In April, 2016 several experiments were conducted approximately 2 …