Mechanical Engineering Commons^™

An Analysis Of Testing Variables In Rapid Compression Machine Experiments, Jenna Ezzell

Master's Theses (2009 -)

There have been discrepancies noted with regards to experimental data from rapid compression machines (RCM). When data is compared from different RCM facilities, the ignition delay times are inconsistent when inspecting any particular temperature. Currently in publications, if these datasets are compared, the discrepancy is said to be due to heat loss, however this issue has yet to be examined more thoroughly. To determine what the root cause of this discrepancy is, four different fake RCM facilities were created and simulated. There were also different sets of initial conditions used to determine how this may affect the data. They were …

Development Of An Optimal Controller And Validation Test Stand For Fuel Efficient Engine Operation, Jack G. Rehn Iii

Master's Theses (2009 -)

There are numerous motivations for improvements in automotive fuel efficiency. As concerns over the environment grow at a rate unmatched by hybrid and electric automotive technologies, the need for reductions in fuel consumed by current road vehicles has never been more present. Studies have shown that a major cause of poor fuel consumption in automobiles is improper driving behavior, which cannot be mitigated by purely technological means. The emergence of autonomous driving technologies has provided an opportunity to alleviate this inefficiency by removing the necessity of a driver. Before autonomous technology can be relied upon to reduce gasoline consumption on …

A Study In The Use Of Elastic Materials In Expandable Containment Units, Andrew J. Eisenman, Joby Anthony Iii, David Satagaj

Montview Journal of Research & Scholarship

The rigidity of materials in conjunction with the aspect of elasticity has been a concern of modern technologies and construction in recent centuries because of the advantages that expandable storage would bring to the fields of containment units with respect to population growth and space exploration. The world population is currently growing at an exponential rate, and as our population grows, the more important it will become to have containment units that can both contain large volumes of material as well as minuscule amounts of material without wasting space. In order accomplish this, we will need a new type of …

Economic Returns To Clean Water: Evidence From Us Historical Records., Joseph Price

Journal of Undergraduate Research

The purpose of this project was to use linked census records to evaluate the long-run effects of access to clean water. By linking individuals across census years we can specifically determine where they lived during their childhood and also have information about their educational attainment and earnings later in life (using the 1940 census). The project was designed to use a time period when the US was a developing country and beginning to use chlorination to clean its water to assess the economic returns to clean water.

Design And Manufacture Of A Waste Compactor Prototype: A Step Towards Implementing A Non-Burn Health Care Waste Disposal In Developing Countries, Tito Mwinuka

Tanzania Journal of Engineering and Technology (TJET)

Non-burn technology is the only safe way of handling and disposing infectious healthcare waste. It involves steam treatment of infectious waste at temperatures higher than 121 o C for a minimum of 30 minutes before disposing them just like other municipal waste. Infectious healthcare waste is normally only about 10 25% of all healthcare waste. In this paper, design, manufacturing and testing of a waste compactor for reducing waste volume to facilitate its handling is discussed. Preliminary tests show that the waste volume can be reduced to less than 10% of its original volume using the developed compactor. Waste compactors …

Dissipative Elastic Metamaterial With A Lowfrequency Passband, Yongquan Liu, Jianlin Yi, Zheng Li, Xianyue Su, Wenlong Li, Mehrdad Negahban

Department of Mechanical and Materials Engineering: Faculty Publications

We design and experimentally demonstrate a dissipative elastic metamaterial structure that functions as a bandpass filter with a low-frequency passband. The mechanism of dissipation in this structure is well described by a mass-spring-damper model that reveals that the imaginary part of the wavenumber is non-zero, even in the passband of dissipative metamaterials. This indicates that transmittance in this range can be low. A prototype for this viscoelastic metamaterial model is fabricated by 3D printing techniques using soft and hard acrylics as constituent materials. The transmittance of the printed metamaterial is measured and shows good agreement with theoretical predictions, demonstrating its …

Vertical Axis Wind Turbine Wake Model Development, Andrew Ning

Journal of Undergraduate Research

The objective of this research was to develop an aerodynamic wake model for a vertical axis wind turbine (VAWT), and to better understand vertical axis wind turbine performance. We were successful in developing a wake model. Additional work went in to understand trade-offs in power performance with acoustic constraints. The results were two conference papers, two journal papers, and open-source data and code. Additional work in ongoing to extended the wake mode’s usefulness for wake interactions and closely-spaced turbines.

Rebuilding Kidneys, Alonzo D. Cook, Deverly L. Roeder, Jonathan J. Wisco

Journal of Undergraduate Research

The motivation for this work was the tremendous need for replacement kidneys. End-stage renal disease (ESRD) affects over 500,000 patients in the U.S. and costs Medicare $30 Billion annually for dialysis and transplant procedures. Our overall objective was to engineer kidneys from decellularized porcine extracellular matrix (DPECM) scaffolds and cell cultures grown from human progenitor cells. The primary reason for using human cells was to develop non-immunogenic kidneys that can be used to treat the more than 100,000 chronic kidney disease (CKD) patients awaiting a transplant, thus obviating the need for post-transplant immunosuppressive therapy and the associated risks of acute …

Validation Of Adaptive Control Laws Using Optimization And Trajectory Sensitivity, Mario Luca Fravolini, Antonio Ficola, Fabio Radicioni, Tansel Yucelen, Ehsan Arabi

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper it is proposed an easy-to-use verification and validation method for adaptive control laws that relies on time domain simulations. The problem is set as a trajectory falsification problem that is the search of closed loop trajectories that, starting from a set of admissible initial conditions, reach a set of unsafe states. The falsification is placed as a nonlinear optimization problem whose decision variables are the initial condition of the states and the uncertain parameters of the system. The falsification is performed iteratively using the local gradient of the sensitivity function derived from a linearized model of the …

A Decentralized Adaptive Control Architecture For Large-Scale Active-Passive Modular Systems, Benjamin C. Gruenwald, Ehsan Arabi, Tansel Yucelen, Animesh Chakravarthy, Drew Mcneely

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Decentralized control of large-scale active-passive modular systems is considered. These systems consist of physically interconnected and generally heterogeneous modules, where local control signals can be only applied to a subset of these modules (i.e., active modules) and the rest are not subject to any control signals (i.e., passive modules). Using a set-theoretic adaptive control approach predicated on restricted potential functions, we design decentralized command following control architectures for each active module such that they can effectively perform their tasks with strict performance guarantees in the presence of unknown physical interconnections between modules and module-level system uncertainties. The efficacy of the …

An Algorithm For Enlarging The Region Of Attraction Using Trajectory Reversing, Nilay Kant, Dhrubajit Chowdhury, Ranjan Mukherjee, Hassan K. Khalil

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Trajectory reversing is a method commonly used for estimating the region of attraction of stabilized equilibria. Using a discrete set of points obtained by trajectory reversing, this paper presents an algorithm for estimation and mathematical representation of the region of attraction using convex hulls. Several two-dimensional examples are presented to illustrate the usefulness of the algorithm. The method provides larger estimates compared to that obtained by existing algorithms, but its main advantage lies in its applicability to higher-order systems. The mathematical representation of the region of attraction is useful in applying the Impulse Manifold Method, which was developed for stabilization …

Enlarging The Region Of Attraction Of Equilibria Of Underactuated Systems Using Sum Of Squares And Impulse Manifold Method, Dhrubajit Chowdhury, Nilay Kant, Ranjan Mukherjee, Hassan K. Khalil

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents an algorithm to enlarge the estimate of the Region of Attraction of stable equilibria of underactuated systems. To achieve this, we use a combination of the Sum of Squares (SOS) method and the Impulse Manifold Method (IMM). Initially, the SOS method is used to optimize the control input u(x) in order to obtain an enlarged Region of Attraction. The IMM is then applied on enlarged Region of Attraction obtained using SOS to further enlarge it. The IMM is implemented using high gain feedback and to demonstrate the efficacy of our algorithm, we present simulation results where an …

Comparing Building Modeling Software To The Energy Record Of A Preexisting Structure, Nathan Lasley

Mahurin Honors College Capstone Experience/Thesis Projects

Buildings are complex systems - even "simple" residential structures. Many factors go into building energy consumption and the design to reduce it. Computer energy modeling allows the simultaneous consideration and balance of many of those variables. Computer models are only as good as the information provided however. Tools like blower door and duct blaster can be used to aid in verifying the model or to provide more information to build a better model. In order to verify of building computer energy simulation methods, the Western Kentucky University (WKU) Office of Sustainability located at 503 Regents Ave. in Bowling Green KY …

A Wood-Powered Lawn Mower: Separating The Rules Of Thumb From Engineering Design, William White

Mahurin Honors College Capstone Experience/Thesis Projects

Biomass gasification, the thermal process of exracting combustible gasses from organic matter, is an established procedure that has been used for many years to provide fuel in various applications. It is a potential source of renewable fuel and has proven useful as a crisis energy source. This thesis investigates the primary engineering science principles involved in gasifier-engine system design. It arises from and supplements a WKU mechanical engineering senior project. The senior project has developed a wood gasification system designed to power a riding lawn mower. The thesis reiews theory-based design and separates it from informal hit and miss approaches—rule …

Multiple Scattering Theory For Heterogeneous Elastic Continua With Strong Property Fluctuation: Theoretical Fundamentals And Applications, Huijing He

Department of Mechanical and Materials Engineering: Faculty Publications

Scattering of elastic waves in heterogeneous media has become one of the most important problems in the field of wave propagation due to its broad applications in seismology, natural resource exploration, ultrasonic nondestructive evaluation and biomedical ultrasound. Nevertheless, it is one of the most challenging problems because of the complicated medium inhomogeneity and the complexity of the elastodynamic equations. A widely accepted model for the propagation and scattering of elastic waves, which properly incorporates the multiple scattering phenomenon and the statistical information of the inhomogeneities is still missing. In this work, the author developed a multiple scattering model for heterogeneous …

Swing-Up Of The Inertia Wheel Pendulum Using Impulsive Torques, Nilay Kant, Ranjan Mukherjee, Hassan K. Khalil

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The swing-up control problem of the inertia wheel pendulum is revisited in this paper. As different from existing methods, purely impulsive control inputs are used for swing-up. A mathematical formulation of the problem indicates that swing-up can be achieved using impulsive inputs applied at two discrete time instants. Two different swing-up schemes are presented and validated using numerical simulations where the impulsive inputs are approximated by high-gain feedback. The results of numerical simulations establish a direct link between high wheel velocities during swing-up and control strategies that take the pendulum directly to the upright configuration. They also indicate that the …

Minimum Required Detection Range For Detect And Avoid Of Unmanned Aircraft Systems, Jared Kevin Wikle, Tim Mclain, Randal W. Beard, Laith Rasmi Sahawneh

Faculty Publications

For unmanned aircraft systems to gain full access to the National Airspace System, they must have the capability to detect and avoid other aircraft. To safely avoid an- other aircraft, an unmanned aircraft must detect the intruder aircraft with ample time and distance to allow the ownship to track the intruder, perform risk assessment, plan an avoidance path, and execute the maneuver. This paper describes two analytical methods for finding the minimum detection range to ensure that these detection and avoidance steps can be carried out. The first method, time-based geometric velocity vectors, includes the bank-angle dynamics of the ownship; …

Detection Of Structural Bolt Detorquing Using Direct Stethoscope Measurement, Joe Guarino, Robert Hamilton

Mechanical and Biomedical Engineering Faculty Publications and Presentations

A method for detecting loosened bolts in a structural joint based upon open-loop acoustic measurement is presented. The acoustic measurement is taken directly on the bolt head. The response of the bolt to a proximal hammer impact is evaluated and characterized using wavelet decomposition of the signal measured from the bolt head. Data were also taken from an accelerometer mounted longitudinally and transversely on the bolt head. Results from the stethoscope and the accelerometer are presented from a set of structural bolts in several conditions of preload and looseness. A stethoscope applied to the loose bolt and a proximal bolt …

A Strategy To Optimize Recovery In Orthopedic Sports Injuries, Michael P. Sealy, Ziye Liu, Chao Li, Yuebin Guo, Ben White, Mark Barkey, Brian Jordon J, Luke N. Brewer, Dale Feldman

Department of Mechanical and Materials Engineering: Faculty Publications

An important goal for treatment of sports injuries is to have as short a recovery time as possible. The critical problem with current orthopedic implants is that they are designed to be permanent and have a high complication rate (15%) that often requires removal and replacement with a second surgery; and subsequently a second rehabilitation cycle. This study was designed to test the feasibility of having a device that could provide the needed mechanical properties, while promoting healing, for a specified amount of time and then degrade away, to shorten the recovery time. The specific strategy was to create a …

Force Compensation And Recreation Accuracy In Humans, Benjamin Rigsby

USF Tampa Graduate Theses and Dissertations

As industry becomes increasingly reliant on robotic assistance and human-computer interfaces, the demand to understand the human sensorimotor system’s characteristics intensifies. Although this field of research has been going on for over a century, new technologies push the limits of the human motor system and our knowledge of it. With new technologies come new abilities, and, in the area of medical care and rehabilitation, the need to expand our knowledge of the sensorimotor system comes from both the patient and physician.

Two studies relating to human force interaction are presented in this thesis. The first study

focuses on humans’ ability …

Investigation Of The Scanning Microarc Oxidation Process, Linqin Xia, Jianmin Han, Joseph P. Domblesky, Zhiyong Yang, Weijing Li

Mechanical Engineering Faculty Research and Publications

Scanning microarc oxidation (SMAO) is a coating process which is based on conventional microarc oxidation (MAO). The key difference is that deposition in SMAO is achieved by using a stainless steel nozzle to spray an electrolyte stream on the substrate surface as opposed to immersing the workpiece in an electrolyzer. In the present study, SMAO discharge characteristics, coating morphology, and properties are analyzed and compared to results obtained from MAO under similar conditions. Results show that MAO and SMAO have comparable spark and microarc lifetimes and sizes, though significant differences in incubation time and discharge distribution were evident. Results also …

Synergistic Effects Of Processing And Nanofiber Reinforcement On The Mechanical And Ferroelectric Performance Of Geopolymer Matrix Composites, Akm S. Rahman, Muhammad E. Hossain, Donald W. Radford

Publications and Research

tThis study involved the evaluation of mechanical and ferroelectric properties of a new classof nanofiller infused inorganic polymer (geopolymer, GP). To evaluate the mechanical per-formance, compressive strength and fracture resistance of neat and nanofillers infused GPwere studied at various treatment temperatures. It was found that, addition of 5 vol% alu-mina nanofiber (ANF), increased compressive strength and modulus by over 30% and 60%,respectively, while it increased fracture toughness (KIC) by over 60% compared to the baselinespecimens. Simultaneously, ferroelectric properties were investigated at various treatmenttemperatures (250◦C, 650◦C and 870◦C). Remarkably, higher ferroelectric hysteresis wasobserved with the GP treated at 870◦C and remnant …

Hysteresis Heating Of Railroad Bearing Thermoplastic Elastomer Suspension Element, Oscar O. Rodriguez, Arturo A. Fuentes, Constantine Tarawneh, Robert E. Jones

Mechanical Engineering Faculty Publications

Thermoplastic elastomers (TPE’s) are increasingly being used in rail service in load damping applications. They are superior to traditional elastomers primarily in their ease of fabrication. Like traditional elastomers they offer benefits including reduction in noise emissions and improved wear resistance in metal components that are in contact with such parts in the railcar suspension system. However, viscoelastic materials, such as the railroad bearing thermoplastic elastomer suspension element (or elastomeric pad), are known to develop self-heating (hysteresis) under cyclic loading, which can lead to undesirable consequences. Quantifying the hysteresis heating of the pad during operation is therefore essential to predict …

Hybrid Fuzzy Logic And Extremum Seeking Attitude Control Of Solar Sail Spacecraft, Nikolai Kalnin

Mechanical Engineering Master's Theses

This thesis explores four controllers applied to the attitude control of a solar sail craft with control masses with the goal of showing benefits over more standard control schemes. The controllers examined in this paper are: 1) a PID controller that incorporates a discrete extremum seeking algorithm, 2) a type-1 fuzzy logic controller that incorporates a discrete extremum seeking algorithm, 3) a type-1 fuzzy logic controller, and 4) a type-2 fuzzy logic controller. The first two controllers are examined for their ability to quickly converge to a set of optimal gains over time. The latter two controllers are evaluated for …

Human-Powered Concrete Mixer, Connor Mcloughlin, Nathan Metzger, Nicholas Szychowski, Madelyn Bustard-Gustafson

Mechanical Engineering Senior Theses

There are currently many non-profit organizations and social enterprises working to alleviate the hardships of living in a developing economy, such as lack of proper homes, schooling, and bathrooms. The solutions to these problems rely on concrete, and are currently limited by the mixing time for these batches of concrete in rural and remote areas. Mixing with shovels is inefficient and imprecise, and the possible solution of a portable gas-powered concrete mixer is too expensive and too immobile for remote areas. The Human-Powered Concrete Mixer (HPCM) provides an alternative to these methods that is more efficient and more precise than …

Techno-Economic Analyses Of Large-Scale Electric Vehicle Systems, Florida Solar Energy Center, Zhihua Qu

FSEC Energy Research Center®

This project developed the process, methodology and algorithms for computer models to evaluate the techno-economic implications of a large-scale electrified transportation sector. The model factors include developing and interacting with a network of electric vehicles and the electric grid, the infrastructure for electric vehicle charging, integrating the transportation and power systems into the urban setting, studying the impact of distributed energy storage and determining the economic impact of increased renewable energy and EVs on the electricity grid and its stability. The modeling related project results are presented in five journal articles and two conference papers. In this final report, the …

Scu Mini Baja, Christian Ruiz, Mauricio Jimenez, Anmol Josen, Christian Hellmers, Angel Robles, Matthew Nagy, Ruben Contreras, Westley Tusa, Chad Russick

Mechanical Engineering Senior Theses

Baja SAE (Society of Automotive Engineers) is an intercollegiate competition to design, fabricate, and race a small, single passenger, off-road vehicle powered by a 10 HP Briggs & Stratton 4-Stroke gasoline engine. The purpose of this project was to optimize the design of a baja vehicle appropriate enough to compete in the SAE competition held in California and perform finite element analysis (FEA) for the verification of the frame and overall design of the vehicle. The design of this vehicle was created through outside research of previous baja buggies made for the competition and the group was split into three …

Energy Payback Time Of A Solar Photovoltaic Powered Waste Plastic Recyclebot System, Shan Zhong, Pratiksha Rakhe, Joshua M. Pearce

Department of Materials Science and Engineering Publications

The growth of both plastic consumption and prosumer 3-D printing are driving an interest in producing 3-D printer filaments from waste plastic. This study quantifies the embodied energy of a vertical DC solar photovoltaic (PV) powered recyclebot based on life cycle energy analysis and compares it to horizontal AC recyclebots, conventional recycling, and the production of a virgin 3-D printer filament. The energy payback time (EPBT) is calculated using the embodied energy of the materials making up the recyclebot itself and is found to be about five days for the extrusion of a poly lactic acid (PLA) filament or 2.5 …

Open Source Multi-Head 3d Printer For Polymer-Metal Composite Component Manufacturing, J. Laureto, Joshua M. Pearce

Department of Materials Science and Engineering Publications

As low-cost desktop 3D printing is now dominated by free and open source self-replicating rapid prototype (RepRap) derivatives, there is an intense interest in extending the scope of potential applications to manufacturing. This study describes a manufacturing technology that enables a constrained set of polymer-metal composite components. This paper provides (1) free and open source hardware and (2) software for printing systems that achieves metal wire embedment into a polymer matrix 3D-printed part via a novel weaving and wrapping method using (3) OpenSCAD and parametric coding for customized g-code commands. Composite parts are evaluated from the technical viability of manufacturing …

Vtol Search And Rescue, Nicholas Keyes, Francesca Caruso, Nick Gagliardi, Joshua Ramayrat, Kia Moazzami

Mechanical Engineering Senior Theses

This project focuses on the design of a hybrid vertical takeoff and landing (VTOL) aircraft that, by using separate propulsion systems, transitions from a quadcopter into horizontal flight. It was designed for use in search and rescue (SAR) missions in national parks due to their high costs, long search times, and the volume of these missions. The aircraft can be easily deployed in less than a couple minutes reducing search time, costs only $2000 saving SAR teams money, and allows for camera integration for hiker location. The aircraft used a pre-built airframe with added modifications, and a specifically designed avionic …