Mechanical Engineering Commons^™

Optimization Methodology For Cvt Ratio Scheduling With Consideration Of Both Engine And Cvt Efficiency, Steven Beuerle

Masters Theses

A transmission ratio schedule is developed to optimize the fuel consumption for an automotive continuously variable transmission (CVT) connected to an internal combustion engine (ICE). Although the optimal operating line (OOL) generated from an engine brake specific fuel consumption (BSFC) map can be used to generate a CVT ratio schedule that yields maximum engine efficiency, it was found that OOL-based CVT ratio scheduling does not necessarily offer the best fuel economy because optimal CVT efficiency does not always correspond to OOL tracking. To develop a CVT ratio schedule that can offer the best fuel economy, a novel ratio-scheduling methodology is …

Analytical Modeling And Numerical Simulation Of A Thermoelectric Generator Including Contact Resistances, Shripad Dhoopagunta

Masters Theses

With increasing demand for energy harvesting systems, research has been conducted in different areas in which Thermoelectric Generators (TEG) find their way into the top of many available resources. Out of many energy harvesting systems available, TEGs are comparatively easier to study, to manufacture and also to comprehend while producing enough energy for applications they find use in. They are solid state devices, meaning; they do not have any moving parts and hence makes them durable. Most of the energy that goes out of the automobile as exhaust is reused to power the TEGs. In most of the works that’s …

Second Law Of Thermodynamics Analysis Of An Internal Combustion Engine Fueled With Methane, Muataz Abotabik

Masters Theses

The second law of thermodynamics is a powerful tool for calculating the amount of energy that can be converted to work (i.e., the exergy or availability of a system), which cannot be predicted using the first law. The objectives of this research project are to quantify the availability during the compression, combustion and expansion processes of a spark-ignited engine fueled with methane; and to highlight differences in the thermo-mechanical availability of the ideal and spark-ignition (SI) engine cycles. A cooperative single-cylinder research engine was used to measure the data required for availability analysis at equivalence ratios ranging between 0.83 and …

An Exploration Of Cubesat Propulsion, Andrew Davis Hine

Masters Theses

The development of new primary propulsion systems for CubeSats with the capability to complete orbital maneuvers has become a principal focus of many within the CubeSat community. One such propulsion device is the 1 cm Busek RF Ion Thruster (BIT-1). For systems such as the BIT-1 to become mission ready and implementable on spacecraft, preliminary testing must be completed to understand how these propulsion devices will perform when placed onboard. The research and testing performed and presented was used to understand how the BIT-1 propulsion device and others like it will interact with small spacecraft. This was accomplished by means …

The Decomposition Of Hydroxylammonium Nitrate Under Vacuum Conditions, Gregory A. Neff

Masters Theses

This research investigates the decomposition of the ionic liquid: hydroxylammonium nitrate (HAN), under vacuum conditions. All research was conducted at the Aerospace Laboratory for Plasma Experiments (ALPE) at Western Michigan University. Hydroxylammonium nitrate solution 24% wt. in H2O was used consistently throughout this research. A variety of temperatures and pressures ranging from 23°C to 645°C and 6E-3 Torr to 4 Torr, respectively, were used to decompose HAN. The primary gaseous species resulting from these decomposition conditions are N2O, NO, and trace amounts of NO2. The formation of H2O, and N2 is conditional on the experimental conditions, and the formation of …

Synthesis And Photonic Sintering Of Bioresorbable Zinc Nanoparticle Ink For Transient Electronics Manufacturing, Bikram K. Mahajan

Masters Theses

"Zinc is an essential 'trace element' that supports immune systems, and is required for DNA synthesis, cell division, and protein synthesis. Zinc nanoparticles (Zn NP) has antibacterial properties and potential to be used in biodegradable printed electronics devices. The research presented here is about the synthesis of Zn NP and their potential use in transient electronics devices. In Paper 1, a technique of room temperature synthesis of Zn NP is reported using ball milling. Controlled amount of PVP was mixed in the solvent to stabilize the Zn particles and minimize cold welding during milling. The size of the produced Zn …

Laser Sintering And Aerosol Printing Of Conductive Nanoparticles, Mahati Guntupalli

Masters Theses

"Fabrication and printing of nanoparticles is an essential step in the manufacturing of low cost- high efficiency electronic devices. High material costs of noble metal particles necessitates the investigation for a potential substituent. Conventional methods of manufacturing are time consuming and uneconomical, thus intense research is being done to employ new methods for cost, time and space effective manufacturing process.

The first part of the thesis presents the fabrication of Copper nanoparticles. As an economical substituent for noble metal nanoparticles, Copper nanoparticles satisfy various properties as conductive inks, simultaneously suffering from the vital problem of oxidation. The acceleration effects of …

Effect Of Sparse-Build Internal Structure On Performance Of Fused Deposition Modeling Parts, Shixuan Meng

Masters Theses

"Fused deposition modeling (FDM) technology has been used in additive manufacturing for years and is able to significantly reduce both manufacturing time and cost for production tooling and end-use parts. Autoclave molding is one of the conventional tools used to produce composite parts. In autoclave molding, the soft composite material is positioned on the molding tool, and then subjected to vacuum and elevated temperatures to facilitate the curing of the resin. With additive manufacturing (AM), it is possible to fabricate the molding tool with a sparse internal structure, thereby reducing the fabrication time and cost compared to a solid tool. …

Effect Of Build Parameters On Mechanical Properties Of Ultem 9085 Parts By Fused Deposition Modeling, Krishna Prasanth Motaparti

Masters Theses

"Additive manufacturing is a fabrication technique that is used to build components by depositing material in a layer-by-layer manner. Fused Deposition Modeling (FDM) is one of the additive manufacturing techniques which is widely used for prototyping and production applications of thermoplastic components. In load bearing applications, the flexural and compression forces often coexist. In order to avoid failure under these loads, it is essential to study the mechanical properties of the components fabricated by FDM. The main focus of this research is to study the mechanical properties of the fabricated components and to comprehend their dependence on various build parameters. …

Prediction Of Surface Roughness In Abrasive Waterjet Cutting Of Graphite Composite Using Response Surface Methodology, Prabhakar Bala

Masters Theses

"In the present work, surface roughness after machining of composite material was the main focus of study. Response surface methodology with Box- Behnken experimental design was applied in predicting the surface roughness (R_a) of abrasive waterjet cut 1-inch-thick graphite/epoxy composite. Second order response equations for R_a were generated with minitab, a statistical software as a function of pressure, traverse speed and isolated abrasive mesh size. Influence of each of these factors on the response were analyzed with 3D response surface plots. Abrasive mesh size was also found be a factor influencing Ra along with traverse speed and …

Mixing Dynamics In Municipal Water Storage Tanks, Pramod Narayan Bangalore

Masters Theses

"The purpose of this study is to investigate the effects of different control variables on mixing in municipal water storage tanks using Computational Fluid Dynamics(CFD) solutions with ANSYS FLUENT for isothermal, positively and negatively buoyant inflow conditions. Poor mixing of old water and new water leads to dead zone formation, which when introduced in the distribution system can cause major water quality issues. Data for this study was generated using Multiphase CFD flow modeling technique using Volume of Fluid (VOF) approach with species transport. The vessel was considered to be mixed when Coefficient of Variation (COV) dropped below 0.10.

Results …

A Linear Matrix Inequality-Based Approach For The Computation Of Actuator Bandwidth Limits In Adaptive Control, Daniel Robert Wagner

Masters Theses

"Linear matrix inequalities and convex optimization techniques have become popular tools to solve nontrivial problems in the field of adaptive control. Specifically, the stability of adaptive control laws in the presence of actuator dynamics remains as an important open control problem. In this thesis, we present a linear matrix inequalities-based hedging approach and evaluate it for model reference adaptive control of an uncertain dynamical system in the presence of actuator dynamics. The ideal reference dynamics are modified such that the hedging approach allows the correct adaptation without being hindered by the presence of actuator dynamics. The hedging approach is first …

Design And Analysis Of An Axisymmetric Aerospike Supersonic Micro-Nozzle For A Refrigerant-Based Cold-Gas Propulsion System For Small Satellites, Abdalla Ali Bani

Masters Theses

"The cold-gas propulsion system being developed by M-SAT requires improvements to its original nozzle design. This study documents the research, design, and analysis of a supersonic plug nozzle concept that could be integrated to the refrigerant-based cold-gas propulsion system to possibly improve its performance. As documented in this thesis, CFD analysis showed that the outlined nozzle design method resulted in a feasible nozzle concept that has the ability to out-perform a conventional nozzle of the same area ratio. The flow-fields and thrust of the aerospike nozzle, for the full and truncated nozzles, were investigated. The purpose of this study is …

Addressing The Influence Of Carbon Monoxide On The Behavior Of An Hcci Engine, Allen Charles Ernst

Masters Theses

"Homogeneous Charge Compression Ignition (HCCI) may be the next leap of improvement to internal combustion engines due to its decreased emissions and improved engine efficiencies. However, such a jump possesses challenges owing to its strict reliance on the inherent physics that dictate start of combustion and limit the reach of stable operation. This work investigates the role and fundamental influence of carbon monoxide on the cycle-to-cycle combustion dynamics present in the region of incomplete combustion that frames the limited HCCI operating region. An improved understanding will open doors to enhanced control methodologies and an expanded stable operating envelope. A constant …

Design Of An Adaptive Force And Stiffness Controlled Compliant Device For Robotic Polishing, Mohammad Masud Parvez

Masters Theses

"Polishing is a repetitive task done in an unhealthy environment. Often more than half of the manufacturing time is required to polish a die. The manual polishing process is a tedious work actively rely on a skilled human worker. Industrial Robot has replaced the human in performing these tasks. For robotic polishing to control the polishing force, an active compliant device is used. Due to the compressibility of air, a pneumatic system is preferred as the actuator of the device. The force of the actuator is controlled by regulating air pressure in both chambers of the cylinder. However, to improve …

Numerical Analysis Of Flexural Slip During Viscoelastic Buckle Folding, Davi Rodrigues Damasceno

Masters Theses

"Flexural slip is considered to be an important folding mechanism contributing in the development of different folds such as chevron, and kink-band buckle folds. Various filed studies have provided a general conceptual and qualitative understanding of flexural slip. However, quantitative evidence of the importance of the flexural slip mechanism during fold evolution is sparse, as the actual amount of surface parallel displacement, and timing, is difficult to measure accurately, due to the lack of suitable strain markers.

In this study 2D finite element analysis is used to overcome these disadvantages and to simulate flexural slip during viscoelastic buckle folding. Variations …

The Evaluation Of Sequential Optimization And Reliability Analysis, Guannan Liu

Masters Theses

"Sequential Optimization and Reliability Assessment (SORA) has been used for more than one decade for reliability-based design (RBD), but comprehensive theoretical studies on its performance have not been conducted. Further investigations on its performance are still needed. The objective of this thesis is to evaluate the performance of SORA for various testing problems. The performance of SORA evaluated in this thesis includes (1) accuracy, (2) efficiency, and (3) convergence behavior or robustness with numerical testing problems. SORA is evaluated with comparison with other major RBD methodologies. The testing problems are in different scales (numbers of design variables, random variables, and …

Composite Model Representation For Computer Aided Design Of Functionally Gradient Materials, Fangquan Wang

Masters Theses

"Functionally Gradient Materials (FGMs) feature smooth transition from one material to another within a single object. FGMs modeling is considered to be one of the new challenges in Computer Aided Design (CAD) area. To overcome this challenge, this thesis presents a composite approach to model FGMs. The input in STL format can be meshed and voxelized in FGMs modeling system. The material composition in each voxel can be generated from multiple different types of control features. And LTI filters including Gaussian Filter and Average Filter are applied to blur default material features in order to generate FGMs inside models. The …

Development Of Learning Objectives For An Undergraduate Computer-Aided Drafting And Design Animation Using The Delphi Technique, Gavin M. Wilk

Masters Theses

This study reflects on learning objectives created for an advanced computer aided drafting (CAD) learning module(s) or course with the emphasis on simulation and engineering animations. These objectives were derived by using the Delphi technique by access the support of a panel of subject matter experts (SME) from academia and industry that are interested in CAD. The results of this study are intended for the use of creating instructional modules for undergraduate studies.

A panel of experts were chosen through an electronic listserv of engineering and technology supporters. Two rounds of two different Delphi survey instruments were utilized to complete …

Design And Fabrication Of A System For The Additive Manufacturing Of Transparent Glass, Luke John Gilbert

Masters Theses

"Despite glass' prevalence in the scientific and engineering community, very little research has been conducted attempting to additively manufacture (AM) glass. Even less research has been done on optically transparent glass. Glass’ material properties make it ineligible for most AM processes if the end result is to be transparent. Even small gas inclusions can cause large amounts of scattering. Additively manufacturing transparent glass brings the advantages found in other AM processes with the added benefit of having optical properties better than those found in polymers. Additively manufacturing glass also allows the optical properties of transparent parts to vary arbitrarily. This …

Multifunctional Wearable Epidermal Device For Physiological Signal Monitoring In Sleep Study, J V M S Avinash Kankipati

Masters Theses

"Sleep is the essential part of life. Thousands of people are suffering from different kinds sleep disorders. Clinical diagnosing and treating for such disorders are costly, painful and quite sluggish. To reach the demand many commercial products are into the market to encourage home based sleep studies using portable devices. These portable devices are limited in use, cannot be handled easily and quite costly. Advancements in technology miniaturized these portable devices to wearable devices to make them convenient and economical. Elastic, soft and thin silicon membrane with physical properties well matched with that of the epidermis provides conformal and robust …

Hybrid Manufacturing Processes For Fusion Welding And Friction Stir Welding Of Aerospace Grade Aluminum Alloys, Megan Alexandra Gegesky

Masters Theses

"Friction stir welding and processing can provide for joints in aerospace grade aluminum alloys that have preferable material properties as compared to fusion welding techniques. Aerospace grade aluminum alloys such as AA2024-T3 and AA7075-T6 are considered non-weldable by traditional fusion welding techniques. Improved mechanical properties over previously used techniques are usually preferable for aerospace applications. Therefore, by combining traditional fusion welding and friction stir processing techniques, it could be plausible to create more difficult geometries in manufactured parts instead of using traditional techniques. While this combination of fusion welding and friction stir processing is not a new technology, its introduction …

Engine Sound Simulation And Generation In Driving Simulator, Shuang Wu

Masters Theses

"Simulating a driving environment that provides engine sound as auditory feedback to the driver is a challenging task due to the complexity of engine sound, a wide range of operating speeds, and repeated sound clicking during playback. This thesis describes a method of engine sound simulation and generation for a driving simulator. By analyzing sample sounds, spectral modeling synthesis was used to decompose the sound samples into deterministic and stochastic components. Then, the modeled deterministic and stochastic signals were employed to resynthesize the sounds. To represent engine sounds not available in the recorded database, sound interpolation was applied to two …

Implementing A Linear Quadratic Spacecraft Attitude Control System, Daniel Kolosa

Masters Theses

This thesis implements a linear quadratic attitude control system for a low-thrust spacecraft. The goal is to maintain spacecraft alignment with a time-varying thrust vector needed for trajectory change maneuvers. A linear quadratic attitude control approach is used to maintain spacecraft pointing throughout flight. This attitude control strategy uses the thrust-acceleration input obtained from a linear quadratic optimal trajectory control model that simulates the trajectory of a spacecraft in orbit maneuvers. This attitude model simulates a CubeSat, a small satellite that is equipped with a low-thrust propulsion and attitude control system. An orbit raising and a plane change scenario is …

Loss On Ignition Using Infrared Heating, Benjamin J. Binoniemi

Masters Theses

The focus of this study is a proof of concept that infrared heating can be used to produce a reliable and rapid method of performing the loss on ignition test. The loss on ignition test is a foundry industry standard test that requires all moisture and volatile organic compounds be vaporized from a sample of foundry sand. The standard test as recommended by the American Foundry Society uses a muffle oven and requires nearly four hours to perform. This new concept performs the same test in approximately ten minutes. The biggest issues with the loss on ignition test are time …

Experimental And Computational Analysis Of Thermosyphon Based Water Heaters, Siddarth Ashokkumar

Masters Theses

"Storage type electric water heaters are one of the most commonly found type of heaters in households today. Due to energy costs and limited generation capacity, there is a need for improving the efficiency of such water heaters. The efficiency of water heating systems have impact both at the household and at the national level, because of their sheer numbers. Efficient water heaters lead to lower utility bills for the consumer and also reduced demand on the grid supplying electrical power to such households. This leads to a reduction in the amount of fuel used in generating electrical power and …

Numerical Study Of Upstream And Downstream Regions Of One Dimensional Detonation Wave In A Dusty Gas Medium, Shubhadeep Banik

Masters Theses

"In detonative combustion very high temperatures are attained by the burned gases. As a result, a large amount of thermal energy is produced during the combustion process. This heat can affect the state of the unburned fuel through radiation of heat from the burned gases. In this study a one-dimensional model was deemed appropriate to gain insight into the fundamental structure of the detonation wave. In this model, the detonation wave divides the fluid stream into an upstream region, consisting of fuel and oxidant, and a downstream region, consisting of burned gases. A set of computer programs, some developed during …

Parameter Determination And Experimental Validation Of A Wire Feed Additive Manufacturing Model, Kannan Suresh Kumar

Masters Theses

“Laser metal deposition is an additive manufacturing method with great scope and robustness. The wire fed additive manufacturing method has great opportunities in space applications and other zero gravity manufacturing processes. Process parameters play an important role in controlling the complex phenomenon and obtaining an ideal manufactured part. These parameters can be efficiently determined using simulation tools which are highly essential in visualizing real world experiments, therefore saving time and experimental costs. The objective of this study is to develop a transient 3D model of laser aided wire feed metal deposition which realizes the heat transfer and fluid flow behavior …

A Force Feedback Haptic Interface For Atomic Force Microscopy, Abdulmohsen Alabdulmuhsin

Masters Theses

"Integrating a force feedback haptic device with atomic force microscopy (AFM) improves the capability to investigate and manipulate the objects on a micro- and nanoscale surface. The haptic device provides the researcher with a sense of touch and movement by changing the position of the stylus or amount of force on it. The developed system's concept is to provide the user a sense and feel and control of the AFM probe at the nanoscale. By positing the haptic stylus, the user generates reference to commands to the AFM probe. In turn, forces experienced by the probe are communicated to the …

On The Dynamic Analysis Of Compliant Mechanisms Based On The Pseudo-Rigid-Body Model, Andrew Christian

Masters Theses

"Compliant mechanisms derive some or all of their mobility from the deflection of flexible members. A pseudo-rigid-body model (PRBM) provides an elegant and simple way of modeling and analyzing traditionally nonlinear large-deflection problems pertaining to compliant mechanisms. In this work, several aspects pertainting to the dynamics of compliant mechanisms are considered. First, dynamic models are derived to predict not only the natural frequency of the large-deflection systems, but also the transient response, using the PRBM approach. A unique multi-stage damping model is developed to determine the transient response in free vibration. Recent works have neglected to consider the transient response …