Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 47

Full-Text Articles in Mechanical Engineering

Mechanical And Aerospace Engineering, 2018-2019, College Of Engineering And Applied Sciences Jan 2019

Mechanical And Aerospace Engineering, 2018-2019, College Of Engineering And Applied Sciences

Mechanical and Aerospace Engineering News

  • Letter from the Chair
  • Introducing Dr. Zachary D. Asher
  • Department of Mechanical and Aerospace Engineering develops an engineering flight simulator
  • Gear Sliding Loss Prediction
  • Ph.D. student receives the prestigious NASA Earth and Space Science Fellowship
  • NSF grant allows important materials research
  • Student receives scholarship from gear industry
  • Development of low cost/high volume micro/nano sensors and actuators
  • Liou receives $204,000 NSF grant for neurological research
  • Alexander Porter inducted into the Alumni Excellence Academy


Hybrid Processes In Material Removal Of Hard And Brittle Materials, Hossein Mohammadi Dec 2018

Hybrid Processes In Material Removal Of Hard And Brittle Materials, Hossein Mohammadi

Dissertations

New technologies demand new materials with better mechanical, optical, and thermal properties. Materials that are light weight, strong with high resistance to high temperatures, and compatible with a predetermined condition. Such materials usually are challenging to manufacture and process compared to widely available materials such as metals. Ceramics and semiconductors are considered extremely hard and brittle, making them very difficult to cut and manufacture. The other major and fast-growing type of materials are composites (including Ceramic Matrix Composites, CMC) that are also considered very challenging to machine. All these materials have many applications in major industries (i.e. electronics, aerospace ...


Decomposition And Ionization Of Ionic Liquids, Forrest Grady Kidd Iii Aug 2018

Decomposition And Ionization Of Ionic Liquids, Forrest Grady Kidd Iii

Dissertations

The United States Air Force is interested in developing a situationally responsive space environment. In order to achieve this, dual-mode-propulsion will be utilized. A new class of propellants is being developed for this application based on energetic ionic liquids. Two ionic liquids of current interest are Hydroxylammonium Nitrate (HAN) and Hydroxyethylhydrazinium Nitrate (HEHN) due to their beneficial performance characteristics. The decomposition and ionization chemistry of these two species is investigated in this work. Using GAUSSIAN09 software, reactions with important radicals are explored through quantum chemistry. The energetics of reactions as well as the identity of key product complexes are given ...


Mechanical And Aerospace Engineering, 2017-2018, College Of Engineering And Applied Sciences Jan 2018

Mechanical And Aerospace Engineering, 2017-2018, College Of Engineering And Applied Sciences

Mechanical and Aerospace Engineering News

  • Letter from the Chair
  • Introducing Dr. Jinseok Kim
  • Use of 3D Printing at WMU Helps Borgess Cardiologist Plug Holes in the Heart
  • Department of Mechanical and Aerospace Engineering Develops Semi-Virtual Reality Powered Wheelchair Simulator
  • The Western Aerospace Launch Initiative (WALI)
  • 2017 NSF I-Corps Experience of MAE team
  • Matthew Baird's Internship Experiences at JPL and GRC
  • More Department News
  • Faculty Sabbaticals


Model Predictive Power Management Of A Hybrid Electric Propulsion System For Aircraft, Tyler J. Wall Dec 2017

Model Predictive Power Management Of A Hybrid Electric Propulsion System For Aircraft, Tyler J. Wall

Master's Theses

This work presents the switched optimal power flow control for an aircraft with a hybrid electric propulsion system. The propulsion system is a switched system that operates in either of two modes: (i) battery discharging and electric motor propelling and (ii) battery charging and electric motor generating. The aircraft model and components that form the hybrid propulsion system are modeled as either an algebraic power source/sink or as a dynamic model with appropriate power and state interconnections. With the system model defined, a model predictive control power management strategy is set fourth which minimizes a performance index that includes ...


Atmospheric Microbial Community Sampling System For Varying Altitude Collection, Kenneth David Domingue Aug 2017

Atmospheric Microbial Community Sampling System For Varying Altitude Collection, Kenneth David Domingue

Master's Theses

The study of airborne microbial communities in the vertical atmosphere is an area of research in which very little data has been collected and analyzed. Developing a vehicle to house biological sampling equipment that collects, and mitigates contamination is required by a team of biology researchers to perform sampling of atmospheric microbial communities. This study uses a sampler box that is attached to aerostatic vehicles: zero pressure balloons and tethered balloon/kite structures. Zero pressure balloons are used for sampling at altitudes above 150 m above sea level, and tethered balloon/kite structures are used for sampling at 30 m ...


Development Of Empirical And Virtual Tools For The Study Of Bicycle Safety, Brent Kostich Aug 2017

Development Of Empirical And Virtual Tools For The Study Of Bicycle Safety, Brent Kostich

Master's Theses

Bicycles have been used as a form of non-motorized transportation for several hundred years. Recently, their use in the transportation realm has been reinvigorated because of growing population densities and efforts to improve environmental sustainability. However, a large deterrent for public use of the bicycle is concern over its level of safety in the transportation environment. The goal of this thesis is to develop two complementary research tools that advance the study of bicycle safety factors.

First, an instrumented probe bicycle (IPB) is constructed from the ground up. The bicycle is outfitted with an array of sensors that are integrated ...


Satellite Sequencing Optimization Using A Genetic Algorithm, Andrew Verstraete Apr 2017

Satellite Sequencing Optimization Using A Genetic Algorithm, Andrew Verstraete

Research and Creative Activities Poster Day

The problem of mission design for a robotic servicing satellite in geosynchronous Earth orbit (GEO) was investigated. A representative set of potential client satellites was selected, and operational needs were randomly assigned based on the average number of GEO retirements, anomalies, and repositioning maneuvers that currently occur each year. An objective function was developed to represent the value of servicing mission sequences, including client fees, time penalties, and operational risk. A genetic algorithm was then used to find sequences of operations on the potential client set that maximized the objective function’s value. Scenarios were analyzed with the database of ...


Mechanical And Aerospace Engineering, 2016-2017, College Of Engineering And Applied Sciences Jan 2017

Mechanical And Aerospace Engineering, 2016-2017, College Of Engineering And Applied Sciences

Mechanical and Aerospace Engineering News

  • Letter from the Department Chair
  • Mechanical and Aerospace Engineering Wins Grant from DENSO North America Foundation
  • NSF $452,399 award to bring state-of-the-art instrument to WMU
  • Faculty Research
  • Faculty Summer Research
  • Research in Fluid Mechanics and Aerodynamics
  • Auto lab upgrades make it a premier teaching and research facility
  • MAE faculty


Attitude Determination Control Testing System (Helmholtz Cage And Air Bearing), Nicolas Theoret Dec 2016

Attitude Determination Control Testing System (Helmholtz Cage And Air Bearing), Nicolas Theoret

Honors Theses

The WALI team at Western Michigan University requested a test environment to validate their CubeSat’s de-tumbling control system and hardware. The test environment required a Helmholtz cage and spherical air bearing. The Helmholtz cage provides an adjustable magnetic field to simulate low earth orbit; the spherical air bearing simulates the friction free environment the CubeSat will experience in space. In conjunction, the two components create an adjustable system that simulates a satellite in low earth orbit.


Experimental Characterization And Simulation Of Carbon Nanotube Strain Sensing Films, Nagendra Krishna Chaitanya Tummalapalli Dec 2016

Experimental Characterization And Simulation Of Carbon Nanotube Strain Sensing Films, Nagendra Krishna Chaitanya Tummalapalli

Master's Theses

Carbon Nanotubes (CNTs) have excellent mechanical, electrical and electromechanical properties. These properties led to a lot of novel applications. Due to change in electrical properties under mechanical loading, these composites have potential applications in strain sensors, when these are fabricated as films. CNT-based films are commonly fabricated using different physical and chemical techniques based on the property requirements governing those applications. In this work, CNT films were prepared using wet chemical based methods and chemical vapor deposition techniques.

Plasma chemical vapor deposition using microwave power is used in the first method to deposit films on silicon substrates, using Nickel film ...


A Genetic Algorithm Incorporating Design Choice For The Preliminary Design Of Unmanned Aerial Vehicles, Kenneth Michael Mull Dec 2016

A Genetic Algorithm Incorporating Design Choice For The Preliminary Design Of Unmanned Aerial Vehicles, Kenneth Michael Mull

Master's Theses

Unmanned Aerial Vehicles (UAVs) are currently at the forefront of aerospace technologies. The design of these aircraft is complex and often performance characteristics are coupled to multiple design attributes. At the early design phase both discrete and continuous design choices are present limiting the feasibility of traditional derivative based optimization techniques. In place of these methods, the design space can be explored using a genetic algorithm that mimics the process of natural selection, providing a capable and reliable base airframe constructed from the required performance metrics. By incorporating a genetic multidisciplinary optimization algorithm early in the conceptual design phase, aircraft ...


Modeling, Optimizing And Testing Thermoelectric Generators For Liquid-To-Liquid Low Grade Waste Heat Recovery, Ali Eyddan Hamil Dec 2016

Modeling, Optimizing And Testing Thermoelectric Generators For Liquid-To-Liquid Low Grade Waste Heat Recovery, Ali Eyddan Hamil

Master's Theses

The use of thermoelectric generators (TEGs) for producing electricity from low grade waste heat is thought to be a great solution in the future to reduce the power generation cost because of their advantages of reliability and environmental friendliness. Therefore, the current project aims to study thermoelectric generators for low grade waste heat recovery. In this work, a single unit cell of liquid to liquid thermoelectric generator attached with heat exchangers (heat sinks) is modeled using an internal flow. Its optimum design is obtained based on heat sink optimization and the optimal design method. An analytical model of four unit ...


Development Of An Analytical Model For Beams With Two Dimples In Opposing Directions, Mofareh H. Ghazwani Dec 2016

Development Of An Analytical Model For Beams With Two Dimples In Opposing Directions, Mofareh H. Ghazwani

Master's Theses

Structures such as beams and steel plates can produce potentially high levels of unwanted vibrations and noises in the environment. A method of improving the vibration and acoustic characteristics of beams based on introducing dimples on its surfaces will be presented in this study. This method focuses on creating two dimples in the same and opposite direction on beam’s surface where the effect of dimples on the change in beam’s natural frequencies is the problems of interest.

A boundary value model (BVM) is developed for a beam with two dimples and subjected to various boundary conditions using Hamilton ...


Analytical Modeling And Numerical Simulation Of A Thermoelectric Generator Including Contact Resistances, Shripad Dhoopagunta Dec 2016

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

Master's 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 ...


Analytical Study Of Miniature Thermoelectric Device, Mohammed Dhannoon Dec 2016

Analytical Study Of Miniature Thermoelectric Device, Mohammed Dhannoon

Master's Theses

Miniature thermoelectric devices (TE) have been regarded as hopeful devices to attain efficient cooling in microprocessors and other small-scale devices. To recognize the performances of miniature thermoelectric coolers, a thermoelectric cooling module is theoretically analyzed. Particular attention is paid to the impact of the thermoelectric element length effect and the substrate material type influence on the cooling performance. The electrical contact resistance and thermal contact are taken into account.

Furthermore, miniature thermoelectric is compared with large thermoelectric, and effective material properties of miniature thermoelectric are studied. The obtained results also demonstrate power density (cooling/heating power per unit area of ...


Optimization Methodology For Cvt Ratio Scheduling With Consideration Of Both Engine And Cvt Efficiency, Steven Beuerle Dec 2016

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

Master's 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 ...


Optimal Design Of Automotive Exhaust Thermoelectric Generator (Aeteg), Hassan Fagehi Dec 2016

Optimal Design Of Automotive Exhaust Thermoelectric Generator (Aeteg), Hassan Fagehi

Master's Theses

A consumption of energy continues to increase at an exponential rate, especially in terms of automotive spark ignitions vehicles. About 40% of the applied fuel into a vehicle is lost as waste exhaust to the environment. The desire for improved fuel efficiency by recovering the exhaust waste heat in automobiles has become an important subject. The thermoelectric generator (TEG) has the potential to convert exhaust waste heat into electricity as long as it is improving fuel economy. The remarkable amount of research being conducted on TEGs indicates that this technology will have a bright future in terms of power generation ...


The Decomposition Of Hydroxylammonium Nitrate Under Vacuum Conditions, Gregory A. Neff Apr 2016

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

Master's 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 ...


Mechanical And Aerospace Engineering, 2015-2016, College Of Engineering And Applied Sciences Jan 2016

Mechanical And Aerospace Engineering, 2015-2016, College Of Engineering And Applied Sciences

Mechanical and Aerospace Engineering News

  • Letter from the Department Chair
  • New Faculty
  • Student Success
  • University NanoSatellite Program P-Spec Mission
  • WALI Student Opportunities
  • Study of Blind Cane Vibration


Studying The Optimum Design Of Automotive Thermoelectric Air Conditioning, Alaa Attar Dec 2015

Studying The Optimum Design Of Automotive Thermoelectric Air Conditioning, Alaa Attar

Dissertations

The remarkable amount of research being conducted on thermoelectrics gives the impression that this technology will have a bright future in power generation and temperature control systems. At the present time, thermoelectrics is applied widely for temperature control, but has not yet replaced conventional air-conditioning systems due to its lower performance. Currently, approximately 10% of annual vehicle fuel consumption corresponds to the air-conditioning system used to cool the vehicle cabin. Conventional air-conditioning systems cool the entire cabin; however, about 73% of a vehicle’s mileage occurs while the driver is the only occupant. These facts indicate the need for a ...


Implementing A Linear Quadratic Spacecraft Attitude Control System, Daniel Kolosa Dec 2015

Implementing A Linear Quadratic Spacecraft Attitude Control System, Daniel Kolosa

Master's 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 ...


Analysis Of Vibroacoustic Properties Of Dimpled Beams Using A Boundary Value Model, Kyle R. Myers Jun 2015

Analysis Of Vibroacoustic Properties Of Dimpled Beams Using A Boundary Value Model, Kyle R. Myers

Dissertations

Attention has been given recently to the use of dimples as a means of passively altering the vibroacoustic properties of structures. Because of their geometric complexity, previous studies have modeled dimpled structures using the finite element method. However, the dynamics of dimpled structures are not completely understood. The goal of this study is to provide a better understanding of these structures through the development of a boundary value model (BVM) using Hamilton's Variational Principle. The focus of this study is on dimpled beams, which represent the simplest form of a dimpled structure.

A general model of a beam with ...


Modeling Of Environmentally Assisted Fatigue Crack Growth Behavior, Sree Phani Chandar Reddy May 2015

Modeling Of Environmentally Assisted Fatigue Crack Growth Behavior, Sree Phani Chandar Reddy

Dissertations

The formation of fatigue cracks and their propagation due to cyclic loading in metals have been a concern for more than hundred years. Since fatigue failure were first reported by the railroad industry in 1840s, tremendous progress has been achieved in understanding fatigue behavior of metals. But fatigue damage is still a concern due to its complex dependency on various environmental variable like humidity, temperature, time and corrosive environment. Although numerous theories and models have been proposed in the past, the effects of environment on fatigue crack growth (FCG) is not completely understood. This dissertation aims to shed light on ...


Electroplating Of Nickel And Copper Layers On Nanoengineered Plastics, Brandon Voelker, Muralidhar K. Ghantasala, Jeff Wheeler Apr 2014

Electroplating Of Nickel And Copper Layers On Nanoengineered Plastics, Brandon Voelker, Muralidhar K. Ghantasala, Jeff Wheeler

Research and Creative Activities Poster Day

Introduction

  • The motivation for this project is the development and proposed use of novel nanoengineered polymeric materials in many industrial and commercial applications. This necessitated the development of a robust metallic coating that can withstand aggressive environmental conditions.
  • This research explores the methods of electroplating nickel and copper to the substrate, including the effects of various duty cycles and cathode current density


Broncoblade: An Open Source Wind Turbine Blade Analysis Tool, Alex R. Quinlan Apr 2013

Broncoblade: An Open Source Wind Turbine Blade Analysis Tool, Alex R. Quinlan

Master's Theses

This thesis reports the development and validation of BroncoBlade, a horizontal axis wind turbine analysis tool. BroncoBlade prepares finite element models and integrates them with an aeroelastic simulator. Analysis results for the SNL100-00 baseline blade are evaluated against reference results published by Sandia National Laboratories. Variations on the SNL100-00 blade incorporating carbon fiber are compared to the baseline blade.


Development Of Cfd Models For The Purposes Of Exploring Free Surface Wave Phenomena, Leonard P. Stoehr Apr 2013

Development Of Cfd Models For The Purposes Of Exploring Free Surface Wave Phenomena, Leonard P. Stoehr

Master's Theses

With the push for finding alternative, green energy sources, the harnessing of energy from ocean and lake waves is becoming a more researched field. To fully understand the behavior of wave interactions and optimize designs to extract this energy, it is necessary to develop computer models that can accurately replicate this behavior. A case is presented in which previous work done using the wave tank found in the Western Michigan University fluids lab is examined. The case involves harnessing the energy generated by ocean waves through the usage of plates of different shapes resting horizontally on the water’s surface ...


Microgas Turbine Engine Characteristics Using Biofuel, Edmond Ing Huang Tan, William W. Liou Feb 2012

Microgas Turbine Engine Characteristics Using Biofuel, Edmond Ing Huang Tan, William W. Liou

The Hilltop Review

Aviation fuels commonly used today are extracted from the kerosene fraction of the crude oil that is distilled between the gasoline and the diesel. Crude oil is not renewable and the world oil reserve is generally believed to be on the decline. In 2006, 6.3% of the world's refinery production was used for aviation fuel (Nygren et. al., 2009). At an estimated rate of 3% increase of fuel demand per year, aviation use alone will consume the world fuel production by 2026. Therefore, there is a need for the aviation industry to reduce its dependence on fossil fuels ...


Ductile Mode Material Removal Of Ceramics And Semiconductors, Deepak Ravindra Jan 2011

Ductile Mode Material Removal Of Ceramics And Semiconductors, Deepak Ravindra

Dissertations

Ceramics and semiconductors are hard, strong, inert and lightweight. They also have good optical properties, wide energy bandgap and high maximum current density. This combination of properties makes them ideal candidates for tribological, semiconductor, MEMS and optoelectronic applications respectively. Manufacturing these materials without causing surface and subsurface damage is extremely challenging due to their high hardness, brittle characteristics and poor machinability. However, ductile regime machining of these materials is possible due to the high-pressure phase transformation occurring in the material caused by the high compressive stresses induced by the single point diamond tool tip. In this study, to further augment ...


Beading And Dimpling Techniques To Improve The Vibration And Acoustic Characteristics Of Plate Structures, Nabeel Taiseer Alshabtat Jan 2011

Beading And Dimpling Techniques To Improve The Vibration And Acoustic Characteristics Of Plate Structures, Nabeel Taiseer Alshabtat

Dissertations

A method of improving the vibroacoustic characteristics of beams and plates is presented. This method is based on creating dimples or beads on the surface of the structures. The proposed method couples the finite element method with an optimization technique based on the genetic algorithm (GA). The improvement of the vibroacoustic characteristics of beams and plates is achieved by two separate strategies. The first strategy is optimizing the natural frequencies of beams and plates. The second strategy is minimizing the sound radiation from such vibrating structures. Optimizing the natural frequencies of some types of beams and simply supported plates by ...