Engineering Commons^™

Classification Of Marine Vessels In A Littoral Environment Using A Novel Training Database, Robert Andrew Lister

Master's Theses - Daytona Beach

Research into object classification has led to the creation of hundreds of databases for use as training sets in object classification algorithms. Datasets made up of thousands of cars, people, boats, faces and everyday objects exist for general classification techniques. However, no commercially available database exists for use with detailed classification and categorization of marine vessels commonly found in littoral environments. This research seeks to fill this void and is the combination of a multi-stage research endeavor designed to provide the missing marine vessel ontology. The first of the two stages performed to date introduces a novel training database called …

Supervisory Autonomous Control Of Homogeneous Teams Of Unmanned Ground Vehicles, With Application To The Multi-Autonomous Ground-Robotic International Challenge, Katrina L. Corley

Master's Theses - Daytona Beach

There are many different proposed methods for Supervisory Control of semi-autonomous robots. There have also been numerous software simulations to determine how many robots can be successfully supervised by a single operator, a problem known as fan-out, but only a few studies have been conducted using actual robots. As evidenced by the MAGIC 2010 competition, there is increasing interest in amplifying human capacity by allowing one or a few operators to supervise a team of robotic agents. This interest provides motivation to perform a more in-depth evaluation of many autonomous/semiautonomous robots an operator can successfully supervise. The MAGIC competition allowed …

Hydrostatic Pressure Testing Of A Square-Cross Section Stainless Steel Propellant Tank Manufactured Using Selective Laser Sintering, Spencer Fuller

Master's Theses - Daytona Beach

The purpose of this study was to determine if parts manufactured using metal selective laser sintering (SLS) exhibit the same isotropic material properties as conventionally made metal parts. This was accomplished by performing a hydrostatic pressure test (HPT) of a metal SLS manufactured propellant tank, constructed for a nano-satellite of the cubesat class. Strain measurements from twelve strain gage locations on the propellant tank were recorded. A finite element analysis (FEA) model, which assumes isotropic material properties, was generated and a FEA analysis was ran at several pressure loads. The tanks strain data at the corresponding pressure loads from the …

Neural Network Prediction Of Ultimate Compression After Impact Loads In Graphite-Epoxy Coupons From Ultrasonic C-Scan Images, Nikolas L. Geiselman

Master's Theses - Daytona Beach

The purpose of this project was to investigate how accurately an artificial neural network could predict the ultimate compressive loads of impact damaged 24-ply graphite-epoxy coupons from ultrasonic C-scan images. The 24-ply graphite-epoxy coupons were manufactured with bidirectional preimpregnated tape and cut into 21 coupons, 4 inches by 6 inches each. The coupons were impacted at known impact energies of 10, 12, 14, 16, 18, and 20 Joules in order to create barely visible impact damage (BVID). The coupons were then scanned with an ultrasonic C-scan system to create an image of the damaged area. Each coupon was then compressed …

Guidance, Navigation And Control Of A Fly-By-Wire Transport Category Airship Designed For Hover Cargo Delivery, Harshad H. Lalan

Master's Theses - Daytona Beach

The purpose of this thesis is to develop fly-by-wire pilot controls for a transport category airship propelled with six thrust vectoring engines, and to develop control laws to maintain position, heading, and attitude during hover and cargo operations. Owing to the large body area, most airships require that they be pointed into the wind to maintain their position. This research aims at controlling an airship attitude and position during hover cargo delivery, irrespective of the wind direction.

Control laws were developed for two primary modes of the airship: Flight (High Speed Mode) and Hover (Cargo Delivery Mode). Different sets of …

Development Of Multidisciplinary Design Optimization Process For A Large Scale Hybrid Composite Wind Turbine Blade, Jin Woo Lee

Master's Theses - Daytona Beach

Development of a multidisciplinary design optimization (MDO) of a large scale hybrid composite wind turbine blade is performed. Multiple objectives are considered in the MDO process to maximize annual energy production and lifetime profit, minimize weight and power production rate. A wind turbine blade is divided into regions and the layup sequences for each region are considered as design variables. The scale of wind turbine blade is also considered to find the optimum size of a wind turbine blade. Applied loads due to extreme wind conditions for rotor rotation and rotor stop condition are considered for finite element analysis (FEA) …

Effect Of Thermally Induced Deformation In A Supersonic Combustion Facility, Aditya Ajit Gupte

Master's Theses - Daytona Beach

Nastran and ANSYS finite element analysis (FEA) and Wind-US computational fluid dynamics (CFD) solvers are used to simulate the effect of thermal deformation on the reacting flow developing within the University of Virginia (UVa) Supersonic Combustion Facility (SCF). A detailed thermal-structural model is developed to resolve the temperature distribution and the resulting structural deformation taking place within the scramjet engine flowpath. The predicted thermal deformation is used to refine the CFD model and produce a new set of results for direct comparison with experiment during both ramjet and scramjet modes of operation. Improved agreement between CFD and experiment is afforded …

The Effects Of System Reliability And Task Uncertainty On Unmanned Aerial Vehicle Operator Performance Under High Time Pressure, Manuela Jaramillo

Master's Theses - Daytona Beach

For many years, the military has understood the value and versatility of Unmanned Aerial Systems (UAS). In the recent years, UASs have sparked the interest of other fields, and in the very near future, they will be introduced into the National Airspace System (NAS). With this inclusion come new concerns. Due to the future wide range applications for UASs, it is important to explore factors, which may affect operator performance. The UAS operator task differs from that of a manned aircraft pilot. An UAS operator does not get the same sensory cues as a pilot and their field of vision …

The Development Of A Phase Locked Wind Turbine Blade Finite Element Model To Predict Loads And Deflections During Fatigue Testing, Kyle Freeman

Master's Theses - Daytona Beach

Full scale blade testing provides blade manufacturers with quantitative data in order to assess blade design, manufacturing and durability. Structural testing is a requirement in order to design reliable blades, and to develop a further understanding of the dynamics involved in a modern turbine blade. Blade tests can be conducted in either a single axis or dual axis configurations. Historically, fatigue testing has been performed by utilizing forced displacement systems. These systems do not allow for the load phase angle to be controlled, and the maximum load application in the edge and flap directions are allowed to vary. The PhLEX …

The Development Of An Adaptive Control System For A Phase-Locked Excitation (Phlex) Method For Advanced Wind Turbine Blade Fatigue Testing, William Michael Haupfear

Master's Theses - Daytona Beach

The National Renewable Energy Laboratory's (NREL) National Wind Technology Center (NWTC) provides the means necessary for advanced wind turbine blade testing. To improve on the current testing methods, a new testing method is being developed using the existing dual-axis fatigue testing capabilities in conjunction with another actuator to provide a phase-locked excitation method with adaptive algorithms and advanced control system strategies. This testing method will provide a more representative loading of the blade for fatigue testing as compared to loading seen in the field. The control system will integrate the MTS software and controller with a supervisory controller, programmed in …

Investigation Of Scaling Effects For A Synthetic Jet Actuator Using High And Low Fidelity Analyses, Amandine Bourlier

Master's Theses - Daytona Beach

This research presents an investigation on the scaling effects for synthetic jet actuators using Ansys-CFX and a Lumped Element Model (LEM). Synthetic jets or zero net mass-flux devices use a vibrating diaphragm to generate an oscillatory flow through a small orifice. A synthetic jet actuator can be used on MAVs as thrust generator or fixed on an airfoil for flow separation control. A Computational Fluid Dynamics (CFD) model was created, using Ansys-CFX, to be validated against referred publications. The use of mesh adaption is discussed. This baseline model was then used to complete a scaling analysis using a set of …

Neural Network Burst Pressure Prediction In Composite Overwrapped Pressure Vessels Using Mathematically Modeled Acoustic Emission Data, Junya Iizuka

Master's Theses - Daytona Beach

The purpose of this research was to predict burst pressures in composite overwrapped pressure vessels (COPV) using mathematically modeled acoustic emission (AE) data. The AE data were collected during hydrostatic burst (hydroburst) testing often 15-inch (380 mm) diameter COP Vs. The data gathered during these tests were filtered in order to remove long duration hits, multiple hit data, and obvious outliers. Based on the duration, energy, and amplitude of the AE hits, the filtered data were classified into the various failure mechanisms of composites using a MATLAB based self-organizing map (SOM) neural network. Previous research has demonstrated that the parameters …

Estimation Of Air Flow Angles Derived From An Inertial Navigation System, Brett Douglas Mather

Master's Theses - Daytona Beach

The purpose of this study is to explore the use of an Inertial Navigation System as a primary method for measuring aircraft air flow angles in flight testing. The traditional methods used to measure air flow angles consist of sensors external to the aircraft, such as an air data boom or an angle of attack probe. The advantage of using INS to measure air flow angles would be in the simplicity of the instrumentation. All components could be fixed internally, leaving minimal external modifications to the aircraft necessary for instrumentation. This would reduce costs and instrumentation time and enable air …

System Identification And State Estimation For Intake Manifold Charge Flow Temperature Of A Compression Ignition Diesel Engine, Ryle D. Maxson

Master's Theses - Daytona Beach

Intake manifold charge temperature is a factor used in mean value engine models (MVEMs) for the calculation of intake mass air charge and oxygen flow. More stringent emission requirements have led to increased deployment of more advanced engine combustion models onto production engine controllers. Measurement of the temperature via physical thermocouple sensors mounted to the engine intake manifold is both slow, in comparison to the changing conditions of an engine, and undesirable due to the cost and increased complexity of extra sensors. A state estimation model has been evaluated that imitates the function of the intake manifold temperature sensor reading, …

The Taiwan Civil Aviation Safety Reporting (Tacare) System In Aircraft Maintenance: An Evaluation Of The Acceptance Of Voluntary Incident Reporting Programs For Maintenance Personnel In Taiwan, Yi-Fan (Tom) Chen

Master's Theses - Daytona Beach

The purpose of this research was to examine the effectiveness of the Taiwan Civil Aviation safety reporting (TACARE) system for maintenance personnel to improve aircraft safety. The research evaluated what are the issues that affect the participation of the TACARE system. The understandings of the safety culture for maintenance personnel in Taiwan were also analyzed. The research was conducted with a mixed method. The survey and interview were developed to sample the acceptance and opinions regarding the TACARE system for the maintenance personnel in Taiwan. Statistical analysis of the data from 605 survey respondents and 9 interviewees concluded the maintenance …

Extension To Multiple Species Of A Two-Equation Turbulence Model For High Speed Flows, Martin Horvath

Master's Theses - Daytona Beach

The Wilcox (2006) k-co turbulence model has been extended to multiple species and implemented in a CFD code for high speed flows using the Steger-Warming flux-vector splitting scheme. The model was chosen because compressibility corrections are not required, nor are viscous damping factors or wall functions to produce the law of the wall, and it has previously been validated for approximately one hundred test cases ranging from incompressible to hypersonic flow regimes. Initial validation cases using first-order accuracy have been performed, including a Mach 2.5 flow past a backward-facing step and a Mach 2.85 flow into a 24° compression corner. …

Nonlinear Observers For Human-In-The-Loop Control Systems, Samuel Kitchen Mckinley

Master's Theses - Daytona Beach

The development of models for a human-in-the-loop with hardware is an area of ongoing research. The ability to simulate a human-in-the-loop with hardware provides a platform for better understanding the dynamics of human and machine cognition. A human-in-the-loop model provides information that can be used to design more efficient human interfaces and smarter autonomous assistant controllers. This can make a complex task such as flying an aircraft safer and more accessible. This thesis explores different possibilities for human operator models to be modeled in the loop with a vehicle. A human is modeled as a linear state feedback controller in …

Redesigning Airport Diagrams With Principles Of Cognitive Psychology, Jacob Miller

Master's Theses - Daytona Beach

The aviation community strives for air travel to be the safest form of transportation. The National Transportation Safety Board published a “Most Wanted” list to acknowledge the most threatening safety issues, and runway safety and runway incursions were at the top of their list. Furthermore, runway incursion statistics by the Federal Aviation Administration show that pilot deviations were the most common cause for runways incursions. Misunderstandings of airport diagrams may be one reason for pilot deviations. While navigating through airport taxiways, pilots refer to their airport diagrams as a map of the airport. Unfortunately, airport diagrams are not designed with …

Numerical Simulation Of A Liquid Jet Atomization And Break-Up Using Ansys-Cfx 12.0, Yash Akhil Bhatt

Master's Theses - Daytona Beach

Break-up and atomization characteristics of JetA liquid fuel were investigated numerically. The results have been compared to various experimental results to evaluate the accuracy of the numerical model. The CFD code ANSYS-CFX 12.0 was used to carry out the steady state analysis at different time scales. A comparison between the atomization characteristics of a pressure jet atomizer and an air-blast atomizer is shown. By employing a Lagrangian particle tracking method to track the path of the liquid particles, the liquid jet/spray phenomena was studied in light of low and high back pressure environments. The 'BLOB' primary atomization model and the …

Neural Network Fatigue Life Prediction In Notched Aluminum Specimens From Acoustic Emission Data, Muhammed Arif Okur

Master's Theses - Daytona Beach

This purpose of this research was to identify fatigue crack growth and predict failure for 7075-T6 aluminum notched bars under uniaxial tensile loading using acoustic emission (AE) data. The experiments performed in this study extend the results obtained by previous researchers who used maximum cyclic loads of 4,000, 3,000, and 2,000 pounds at a stress ratio of R = 0.0 and a frequency of 1 Hz to perform the fatigue tests. For this research the cyclic load remained at 2,000 pounds, but an additional ten specimens were tested in order to increase the amount of AE data available to the …

Effect Of Time Pressure And Task Uncertainty On Human Operator Performance And Workload For Autonomous Aerial Vehicle Missions, Trevor Peterson

Master's Theses - Daytona Beach

Unmanned aircraft systems (UAS) are being utilized at an increasing rate for a number of military applications. The potential for their use in the national airspace is also of interest to the Federal Aviation Administration, but there are some concerns about the safety of flying unmanned aircraft. The role of a UAS operator differs from that of a pilot in a manned aircraft, and this new role creates a need for a shift in interface and task design in order to take advantage of the full potential of these systems. This study examined the effect of time pressure and task …

Parametric Viscous Analysis Of Gust Interaction With Stationary And Elastically Mounted Airfoil, Timothy M. Hollenshade Jr.

Master's Theses - Daytona Beach

This thesis details the development and implementation of a module within a high-accuracy numerical viscous analysis code to simulate the nonlinear interaction of SD7003 airfoil with non-uniform, unsteady incoming flow. The study is focused on the low-Re number unsteady flows typical of MAV applications in which a gust encounter can induce a particularly significant aerodynamic and aeroelastic response. Efficient source models are developed to introduce sharp-edge and time-harmonic gust perturbations with specified amplitude, frequency and duration inside the computational domain through the source terms in the governing momentum equations. Parametric analysis of gust-airfoil interactions for different steady airfoil loads is …

Removal Of Biofilm Through Controlled Cavitation, Mathew Chackalackal Mathew

Master's Theses - Daytona Beach

Human kind is poised to take the next "giant step" in space exploration, the manned mission to Mars, among other things. But before any plans for such long term habitation on an alien planet, there has to be consideration towards prevention and removal of bacterial contamination. Bacterial contamination or rather degradation of materials was considered of negligible importance. Bacterial degradation can be serious for long-term manned space mission, more so because there is no way to obtain quick replacements. For such conditions, a new innovative way of bacterial removal has been proposed wherein the bacteria is removed with no damage …

Numerical Simulation Of Mode Transition In A Hydrogen-Fueled Scramjet, Manan Ajay Vyas

Master's Theses - Daytona Beach

The Wind-US computational fluid dynamics (CFD) flow solver was used to simulate dual-mode direct-connect ramjet/scramjet engine flowpath tests conducted in the University of Virginia (UVa) Supersonic Combustion Facility (SCF). The objective was to develop a computational capability within Wind-US to aid current hypersonic research and provide insight to flow as well as chemistry details that are not resolved by instruments available. Computational results are compared with experimental data to validate the accuracy of the numerical modeling. These results include two fuel-off non-reacting and eight fuel-on reacting cases with different equivalence ratios, split between one set with a clean (non-vitiated) air …

An Analytical Investigation Of Natural Frequency For A Symmetric Composite Box-Beam With Thermal Effects, Lakshmi Narayana Sanjeev Chitikela

Master's Theses - Daytona Beach

The main purpose of the following analysis is to develop an analytical method for determining the natural frequency of a symmetric composite box-beam subjected to temperature gradient. A set of coupled partial differential equations of motion is obtained by means of small defection theory and D'Alembert's method. The Smith and Chopra stiffness matrix is used in the governing equations of motion and an appropriate MATLAB® code has been written to solve for the stiffness matrix elements of the box-beam. The resulting governing equations of motion are solved to obtain the natural frequencies of the box-beam in flap and lag directions …

Thermal Modeling Of Lithium-Ion Energy Storage Systems For Hybrid Electric Vehicles Using Computational Fluid Dynamics With Conjugate Heat Transfer, Craig R. Czlapinski

Master's Theses - Daytona Beach

The success and performance of a Hybrid Electric Vehicle (HEV) relies largely on its Energy Storage System (ESS). High temperatures and thermal variations can significantly affect a battery's performance and lifecycle. An effective thermal management system is vital to the health and safe operation of the ESS's batteries. A well designed thermal management system begins with the accurate prediction of the battery's thermal conditions. In hot climates, HEVs may be required to operate within ten degrees Celsius of the maximum safe operating temperature of their batteries. This study aims to evaluate the thermal management system of a lithium-ion based energy …

Compression After Impact Load Prediction In Graphite/Epoxy Laminates Using Acoustic Emission And Artificial Neural Networks, Anthony Michael Gunasekera

Master's Theses - Daytona Beach

The purpose of this research was to investigate the effectiveness of artificial neural networks (ANNs) in predicting the compression after impact (CAI) load of graphite/epoxy laminates from acoustic emission (AE) nondestructive testing (NDT) data. Thirty-four 24-ply bidirectional woven cloth laminate coupons were constructed and impacted at various energy levels ranging from 8 to 20 Joules, generating barely visible impact damage (BVID). Acoustic emission data were acquired as the coupons were compressed to failure. Not having been analyzed by previous experimenters, several noise tests were also performed to determine the impact of external noise on acoustic emission data during testing. Once …

Determination Of Stability And Control Derivatives For A Modern Light Composite Twin Engine Airplane, Monica M. Londono

Master's Theses - Daytona Beach

To develop and compare full envelope stability and control derivatives and their associated errors for a modern light composite twin engine airplane from flight test data and digital DATCOM (Data Compendium). This development is to serve three purposes 1) to provide data for validation of newer analytical techniques such as Computational Fluid Dynamics (CFD), 2) to provide public domain static and dynamic stability and control derivatives for a modern twin engine airplane, 3) to analyze the relationship between test design and error for both output error and equation error methods.

A flight test program was conducted on a Diamond Twin …

Change Blindness In The Synthetic Vision Primary Flight Display: Comparing Eye Tracking Patterns With Pilot Attention, Stephen A. Mayo

Master's Theses - Daytona Beach

There have been a number of important advances in aviation technology that have made the safety rating of flying the best that it has ever been. One of the most important advances made has been in the interface that the pilot relies on for their most critical information during flight. New aviation displays have empirically shown a wide range of improvements across pilot performance. Despite these improvements, there is still a high possibility that pilots may miss pertinent information that changes may occur simultaneously with some sort of distraction - a concept known as change blindness. This study analyzed how …

The Effect Of Pilot And Air Traffic Control Experiences & Automation Management Strategies On Uas Mission Task Performance, Christopher J. Reynolds

Master's Theses - Daytona Beach

Unmanned aircraft are relied on now more than ever to save lives and support the troops in the recent Operation Enduring Freedom and Operation Iraqi Freedom. The demands for UAS capabilities are rapidly increasing in the civilian sector. However, UAS operations will not be carried out in the NAS until safety concerns are alleviated. Among these concerns is determining the appropriate level of automation in conjunction with a suitable pilot who exhibits the necessary knowledge, skills, and abilities to safely operate these systems.

This research examined two levels of automation: Management by Consent (MBC) and Management by Exception (MBE). User …