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Articles 6061 - 6090 of 11135
Full-Text Articles in Engineering
Machine Vision Identification Of Airport Runways With Visible And Infrared Videos, Andrew J. Moore, Matthew Schubert, Chester Dolph, Glenn Woodell
Machine Vision Identification Of Airport Runways With Visible And Infrared Videos, Andrew J. Moore, Matthew Schubert, Chester Dolph, Glenn Woodell
Electrical & Computer Engineering Faculty Publications
A widely used machine vision pipeline based on the Speeded-Up Robust Features feature detector was applied to the problem of identifying a runway from a universe of known runways, which was constructed using video records of 19 straight-in glidepath approaches to nine runways. The recordings studied included visible, short-wave infrared, and long-wave infrared videos in clear conditions, rain, and fog. Both daytime and nighttime runway approaches were used. High detection specificity (identification of the runway approached and rejection of the other runways in the universe) was observed in all conditions (greater than 90% Bayesian posterior probability). In the visible band, …
First-Year Project Experience In Aerospace: Apogee Determination Of Model Rockets With Explicit Consideration Of Drag Effect, Hüseyin Sarper, Drew Landman, Linda Vahala
First-Year Project Experience In Aerospace: Apogee Determination Of Model Rockets With Explicit Consideration Of Drag Effect, Hüseyin Sarper, Drew Landman, Linda Vahala
Electrical & Computer Engineering Faculty Publications
This paper describes a student team project using model rockets and engines to learn engineering solution methods for determining the apogee of model rocket when the drag effect is considered explicitly instead of estimating its effect later. Model rocketry is a powerful tool for instructors who wish to incorporate science, engineering, and mathematics into a fun, engaging, and challenging activity for the students. The apogee can be determined using a number of distinct methods: trigonometry, onboard altimeters, analytical calculations, and simulation. This paper emphasizes numerical analytical solution using spreadsheet programming instead of a full analytical solution that requires higher mathematics. …
An Investigation Of Inital Shock Cell Formation In Turbulent Coanda Wall Jets, Caroline P. Lubert, Christian R. Schwantes, Richard J. Shafer
An Investigation Of Inital Shock Cell Formation In Turbulent Coanda Wall Jets, Caroline P. Lubert, Christian R. Schwantes, Richard J. Shafer
Department of Mathematics and Statistics - Faculty Scholarship
Turbulent Coanda wall jets are present in a multitude of natural and man-made applications. Their obvious advantages in terms of flow deflection are often outweighed by disadvantages related to the increased noise levels associated with these jets. Primary high-frequency noise sources are turbulent mixing noise (TMN) and shock-associated noise (SAN). Clearly, accurate modeling of these noise sources will facilitate better predictions of the behavior of such jet noise with physical characteristics. This paper, which focuses on SAN, shows how the Method of Characteristics can be applied to a steady two-dimensional axisymmetric supersonic flow to rewrite the three governing partial differential …
Evolution Of Moiré Profiles From Van Der Waals Superstructures Of Boron Nitride Nanosheets, Yunlong Liao, Wei Cao, John W. Connell, Zhongfang Chen, Yi Lin
Evolution Of Moiré Profiles From Van Der Waals Superstructures Of Boron Nitride Nanosheets, Yunlong Liao, Wei Cao, John W. Connell, Zhongfang Chen, Yi Lin
Applied Research Center Publications
Two-dimensional (2D) van der Waals (vdW) superstructures, or vdW solids, are formed by the precise restacking of 2D nanosheet lattices, which can lead to unique physical and electronic properties that are not available in the parent nanosheets. Moiré patterns formed by the crystalline mismatch between adjacent nanosheets are the most direct features for vdW superstructures under microscopic imaging. In this article, transmission electron microscopy (TEM) observation of hexagonal Moiré patterns with unusually large micrometer-sized lateral areas (up to similar to 1μm2 and periodicities (up to similar to 50 nm) from restacking of liquid exfoliated hexagonal boron nitride nanosheets (BNNSs) …
Thrust Sensing For Small Uavs, Christopher Scott Marchman
Thrust Sensing For Small Uavs, Christopher Scott Marchman
Masters Theses
"Unmanned aerial vehicles (UAVs) have become prevalent in both military and civilian applications. UAVs have many size categories from large-scale aircraft to micro air vehicles. The performance, health, and efficiency for UAVs of smaller sizes can be difficult to assess and few associated instrumentation systems have been developed. Thrust measurements on the ground can characterize systems especially when combined with simultaneous motor power measurements. This thesis demonstrates the use of strain measurements to measure the thrust produced by motor/propeller combinations for such small UAVs. A full-bridge Wheatstone circuit and electrical resistance strain gauges were used in conjunction with constant-stress cantilever …
Intensity Control Of Dielectric Barrier Discharge Filaments, Matthew Crawford Paliwoda
Intensity Control Of Dielectric Barrier Discharge Filaments, Matthew Crawford Paliwoda
Masters Theses
"When operated in a filamentary mode, a volume dielectric barrier discharge (DBD) is known to produce patterned plasma structures. These structures are currently being explored for reconfigurable metamaterial applications. In this work the presence and intensity of a single filament, within an array of filaments, was controlled by adjusting the voltage to that filament's individual needle electrode. The current, voltage, and time-averaged normalized light intensity were measured while varying the voltage of the needle through a self-biasing resistance. For a 7.5 kV, 3.2 kHz DBD in air, the needle-controlled filament intensity varies from that of the surrounding filaments to zero …
Characterization Of Electric Solid Propellant Pulsed Microthrusters, Matthew Scott Glascock
Characterization Of Electric Solid Propellant Pulsed Microthrusters, Matthew Scott Glascock
Masters Theses
"Electric solid propellants are an attractive option for space propulsion because they are ignited by applied electric power only. In this work, the behavior of pulsed microthruster devices utilizing such a material is investigated. These devices are similar in function and operation to the pulsed plasma thruster, which typically uses Teflon as propellant. A Faraday probe, Langmuir triple probe, residual gas analyzer, pendulum thrust stand and high speed camera are utilized as diagnostic devices. These thrusters are made in batches, of which a few devices were tested experimentally in vacuum environments. Results indicate a plume electron temperature of about 1.7 …
Restraint System Design And Evaluation For Military Specific Applications, Sebastian Karwaczynski
Restraint System Design And Evaluation For Military Specific Applications, Sebastian Karwaczynski
Dissertations, Master's Theses and Master's Reports
This research focuses on designing an optimal restraint system for usage in a military vehicle applications. The designed restraint system must accommodate a wide range of DHM’s and ATD’s with and without PPE such as: helmet, boots, and body armor. The evaluation of the restraint systems were conducted in a simulated vehicle environment, which was utilized to downselect the ideal restraint system for this program.
In December of 2011 the OCP TECD program was formulated to increase occupant protection. To do this, 3D computer models were created to accommodate the entire Soldier population in the Army. These models included the …
Nanoionics And Nanocatalysts: Conformal Mesoporous Surface Scaffold For Cathode Of Solid Oxide Fuel Cells, Yun Chen, Kirk Gerdes, Xueyan Song
Nanoionics And Nanocatalysts: Conformal Mesoporous Surface Scaffold For Cathode Of Solid Oxide Fuel Cells, Yun Chen, Kirk Gerdes, Xueyan Song
Faculty & Staff Scholarship
Nanoionics has become increasingly important in devices and systems related to energy conversion and storage. Nevertheless, nanoionics and nanostructured electrodes development has been challenging for solid oxide fuel cells (SOFCs) owing to many reasons including poor stability of the nanocrystals during fabrication of SOFCs at elevated temperatures. In this study, a conformal mesoporous ZrO2 nanoionic network was formed on the surface of La1−xSrxMnO3/yttria-stabilized zirconia (LSM/YSZ) cathode backbone using Atomic Layer Deposition (ALD) and thermal treatment. The surface layer nanoionic network possesses open mesopores for gas penetration, and features a high density of grain boundaries for enhanced ion-transport. The mesoporous nanoionic …
Zipping Towards Stem: Simulation Wind Tunnel, Emma Pierson, Greg Flohr, Devon Goldberg, Brandon Hein, Jeremy Hein
Zipping Towards Stem: Simulation Wind Tunnel, Emma Pierson, Greg Flohr, Devon Goldberg, Brandon Hein, Jeremy Hein
Williams Honors College, Honors Research Projects
The simulation wind tunnel was created to be integrated into a larger project funded by the National Science Foundation titled Zipping Towards STEM: Integrating Engineering Design into the Middle School Physical Science Curriculum. The goal of this project is to integrate the engineering design process of computer modeling, simulation, rapid prototyping, and testing into the 8th grade level curriculum by letting students design and test their own mini soap box derby cars. The simulation wind tunnel will be used to help the students understand the basics of aerodynamics so they can design an aerodynamic mini soap box derby …
Rocket Fin Test Fixture Development & Exploration Of Rotation Inducing Fin Design, Ryan A. Saylor Mr., David J. Royak Mr., Jacob P. Byron Mr.
Rocket Fin Test Fixture Development & Exploration Of Rotation Inducing Fin Design, Ryan A. Saylor Mr., David J. Royak Mr., Jacob P. Byron Mr.
Williams Honors College, Honors Research Projects
The purpose of this senior project was to develop a method of applying rotation inducing rocket fin concepts to rockets for the benefit of the University of Akron Akronauts; the student led rocket design team. The project was performed independently of the team’s current efforts as a research and development endeavor for future team projects. Main project goals were divided into three parts: design a fin test fixture for verification testing in the University’s wind tunnel, develop a parameter-driven software model that could be used to generate design options with theoretical performance data as an output, and run fluid dynamics …
Backward Dijkstra Algorithms For Finding The Departure Time Based On The Specified Arrival Time For Real-Life Time-Dependent Networks, Gelareh Bakhtyar, Vi Nguyen, Mecit Cetin, Duc Nguyen
Backward Dijkstra Algorithms For Finding The Departure Time Based On The Specified Arrival Time For Real-Life Time-Dependent Networks, Gelareh Bakhtyar, Vi Nguyen, Mecit Cetin, Duc Nguyen
Civil & Environmental Engineering Faculty Publications
A practical transportation problem for finding the “departure” time at “all source nodes” in order to arrive at “some destination nodes” at specified time for both FIFO (i.e., First In First Out) and Non-FIFO “Dynamic ” Networks is considered in this study. Although shortest path (SP) for dynamic networks have been studied/documented by various researchers, contributions from this present work consists of a sparse matrix storage scheme for efficiently storing large scale sparse network’s connectivity, a concept of Time Delay Factor (TDF) combining with a “general piece- wise linear function” to describe the link cost as a function of time …
Ultra-Compact Raman Spectrometer For Planetary Explorations, Derek Davis, James Hornef, John Lucas, Hani Elsayed-Ali, M. Nural Abedin
Ultra-Compact Raman Spectrometer For Planetary Explorations, Derek Davis, James Hornef, John Lucas, Hani Elsayed-Ali, M. Nural Abedin
Electrical & Computer Engineering Faculty Publications
To develop a compact Raman spectroscopy system with features that will make it suitable for future space missions which require surface landing. Specifically, this system will be appropriate for any mission in which planetary surface samples need to be measured and analyzed.
Small Satellite Noncommutative Rotation Sequence Attitude Control Using Piezoelectric Actuators, Joshua L. Evans
Small Satellite Noncommutative Rotation Sequence Attitude Control Using Piezoelectric Actuators, Joshua L. Evans
Theses and Dissertations--Electrical and Computer Engineering
Attitude control remains one of the top engineering challenges faced by small satellite mission planning and design. Conventional methods for attitude control include propulsion, reaction wheels, magnetic torque coils, and passive stabilization mechanisms, such as permanent magnets that align with planetary magnetic fields. Drawbacks of these conventional attitude control methods for small satellites include size, power consumption, dependence on external magnetic fields, and lack of full control authority. This research investigates an alternative, novel approach to attitude-control method for small satellites, utilizing the noncommutative property of rigid body rotation sequences. Piezoelectric bimorph actuators are used to induce sinusoidal small-amplitude satellite …
Expedient Airfield Runway Repair Using Folded Fiberglass Mat, Christopher Y. Tuan, Willaim C. Dass
Expedient Airfield Runway Repair Using Folded Fiberglass Mat, Christopher Y. Tuan, Willaim C. Dass
Department of Civil and Environmental Engineering: Faculty Publications
For expedient airfield runway repair, the US Air Force has developed a folded fiberglass mat to cover craters repaired with a well-compacted granular base material. The objective of this study was to evaluate the adequacy of using polymer plugs to anchor the mat to a repaired asphalt pavement for heavy aircraft operations. The effort consisted of materials testing, field experiments and analytical modeling. An 89,800-kg (198,000-pound) load cart having the footprint of a single C-5 main gear was pulled on a mat with wheels locked to simulate full braking forces. Anchor bushings were instrumented to measure anchor loads. A simplified …
Design And Use Of The Ionospheric Connection Explorer Payload Mockup, Burt Lamborn, John Elwell, Andy Little, William Craig, Rich Rynders, Eric Moulton
Design And Use Of The Ionospheric Connection Explorer Payload Mockup, Burt Lamborn, John Elwell, Andy Little, William Craig, Rich Rynders, Eric Moulton
Space Dynamics Laboratory Publications
The Ionospheric Connection Explorer (ICON) satellite contains six science instruments that are integrated into a small volume on a single payload interface plate (PIP). Integrating these six instruments onto a single deck was challenging and complex in part due to their different physical configurations. After investigating various methods of reducing integration schedule and risk, an innovative approach of creating a high-fidelity full-scale mockup using 3D printed parts was chosen to address these concerns. This mockup included all instruments, the PIP, and associated harnessing, plumbing, and blanketing components. While the mockup integration effort yielded invaluable information for the flight payload integration, …
Calibration Considerations For A Reduced-Timeline Optimized Approach For Vnir Earth-Orbiting Satellites, Zachary Bergen, Joe Tansock
Calibration Considerations For A Reduced-Timeline Optimized Approach For Vnir Earth-Orbiting Satellites, Zachary Bergen, Joe Tansock
Space Dynamics Laboratory Publications
With the increasing number of commercial satellite constellations launching, the need for calibration remains as relevant as ever. Some of these instruments are built with COTS optical components and, given the number and need for timely calibration, a flexible, dynamic, and streamlined approach is necessary for reproducibility, regression testing, adaptability, and high-quality image data. We present a use case for a commercial VNIR payload and demonstrate techniques and a storyboard of our experience. We ran a calibration campaign on a 100” focal length telescope assembled in a payload of approximate 50kg containing a commercial Bayer pattern camera of medium resolution …
Secondary Flow Of Liquid-Liquid Two-Phase Fluids In A Pipe Bend, M. Ayala, P. Santos, G. Hamester, O. Ayala
Secondary Flow Of Liquid-Liquid Two-Phase Fluids In A Pipe Bend, M. Ayala, P. Santos, G. Hamester, O. Ayala
Engineering Technology Faculty Publications
A simulated study of oil and water in 90 degree bend was carried on COMSOL 5.1 to characterize flow pattern and analyze the secondary flow. The Euler-Euler k-e Reynolds Averaged Navier-Stokes model was used to represent the fluid motion. Changes in the Reynolds number, curvature ratio and direction of gravity were made to evaluate the effects in the intensity of the secondary flow. In the end, it was possible to see that the bend direction does not affect the formation of secondary flow for Reynolds above 100,000. It appears that the fluid behavior on the pipe bend is strongly related …
The Impact Of Automation Reliability And Fatigue On Reliance, Ryan Wohleber
The Impact Of Automation Reliability And Fatigue On Reliance, Ryan Wohleber
Electronic Theses and Dissertations
The objective of this research is to inform the design of dynamic interfaces to optimize unmanned aerial vehicle (UAV) operator reliance on automation. A broad goal of the U.S. military is to improve the ratio of UAV operators to UAVs controlled. Accomplishing this goal requires the use of automation; however, the benefits of automation are jeopardized without appropriate operator reliance. To improve reliance on automation, this effort sought to accomplish several objectives organized into phases. The first phase aimed to validate metrics that could be used to gauge operator fatigue online, to understand how the reliability of automated systems influences …
Di2e: Defense Intelligence Information Enterprise, Space Dynamics Laboratory
Di2e: Defense Intelligence Information Enterprise, Space Dynamics Laboratory
Space Dynamics Laboratory Publications
The rising demand for rapid intelligence software solutions combined with limited Government funding has highlighted the need for an organized process to use resources more efficiently. The solution needed to leverage existing capabilities to meet mission needs and ensure that defense intelligence information flows seamlessly across enterprise boundaries. In response, as a Government initiative, the NRO and AFRL developed the Defense Intelligence Information Enterprise (DI2E) framework as a solution to promote intelligence software asset reuse where possible.
Experimental Validation Data For Cfd Of Forced Convection On A Vertical Flat Plate, Jeff R. Harris, Blake W. Lance, Barton L. Smith
Experimental Validation Data For Cfd Of Forced Convection On A Vertical Flat Plate, Jeff R. Harris, Blake W. Lance, Barton L. Smith
Mechanical and Aerospace Engineering Faculty Publications
A CFD validation data set for turbulent forced convection on a vertical plate is presented. The design of the apparatus is based on recent validation literature and provides a means to simultaneously measure boundary conditions and system response quantities. All important inflow quantities for RANS CFD are also measured. Data are acquired at two heating conditions and cover the range 40;000 < Rex < 300;000, 357 < Red2 < 813 and 0:02 < Gr/Re2 < 0:232. The data and uncertainties are contained in files in the supplemental material
Design Of A 500 Lbf Liquid Oxygen And Liquid Methane Rocket Engine For Suborbital Flight, Jesus Eduardo Trillo
Design Of A 500 Lbf Liquid Oxygen And Liquid Methane Rocket Engine For Suborbital Flight, Jesus Eduardo Trillo
Open Access Theses & Dissertations
Liquid methane (LCH4)is the most promising rocket fuel for our journey to Mars and other space entities. Compared to liquid hydrogen, the most common cryogenic fuel used today, methane is denser and can be stored at a more manageable temperature; leading to more affordable tanks and a lighter system. The most important advantage is it can be produced from local sources using in-situ resource utilization (ISRU) technology. This will allow the production of the fuel needed to come back to earth on the surface of Mars, or the space entity being explored,making the overall mission more cost effective by enabling …
Computational Modeling Of A 60kw Oxy-Methane Direct Power Extraction Combustor, Omar Daniel Vidana
Computational Modeling Of A 60kw Oxy-Methane Direct Power Extraction Combustor, Omar Daniel Vidana
Open Access Theses & Dissertations
ANSYS Fluent was used to optimize components of a direct power extraction combustor. This includes the fuel injector, nozzle, and cooling units. Changes in the injector's inlet location impacted pressure and velocity distribution. An angle of 115 degrees with respect to the x-axis was found to increase distribution efficiency. Temperature and velocity data from the combustor and nozzle were calculated using NASA CEA and Fluent. Magnitudes of temperature and velocity for CEA and Fluent matched within 9% and 4%, respectively. For the cooling system it is expected that cavitation will not occur since the saturation temperature of water is not …
Analysis Of Road Vehicle Aerodynamics With Computational Fluid Dynamics, Christian Armando Mata
Analysis Of Road Vehicle Aerodynamics With Computational Fluid Dynamics, Christian Armando Mata
Open Access Theses & Dissertations
A road vehicles aerodynamics can be one of the most influential aspects of its performance. With the increased importance on fuel efficiency in recent years, new road vehicles are being developed smaller in size, with smaller displacement engines, as well as with improved aerodynamics. The aerodynamics of a vehicle can have a significant effect on its fuel efficiency, as well as other important aspects of the vehicles performance such as the top speed, acceleration, and handling. A study focusing on analyzing aerodynamic effects due to vehicle geometries such as wheels covered by the vehicles body in comparison to open wheels …
Design Structure Method As Applied To The Structural Organization Of A 5th Genertation Fighter Jet, Israel Michel Michel
Design Structure Method As Applied To The Structural Organization Of A 5th Genertation Fighter Jet, Israel Michel Michel
Open Access Theses & Dissertations
In current times, the demand for protection against enemies in a volatile geopolitical climate is an increasingly demanding concern. Many countries invest billions of dollars attempting to protect their borders and in fact strive to become the most powerful and dominant war power in the world. As the dollar amount of each country increases, and while other countries seem to always beat each other, the path for innovations and demand is never ending. The complexity of each project continues to grow as they become very sophisticated in their respective field.
In recent decades, itâ??s been proven that whoever reaches the …
Design And Experimental Investigation Of An Oxy-Fuel Combustion System For Magnetohydrodynamic Power Extraction, Manuel Johannes Hernandez
Design And Experimental Investigation Of An Oxy-Fuel Combustion System For Magnetohydrodynamic Power Extraction, Manuel Johannes Hernandez
Open Access Theses & Dissertations
A general consensus in the scientific and research community is the need to restrict carbon emissions in energy systems. Therefore, extensive research efforts are underway to develop the next generation of energy systems. In the field of power generation, researchers are actively investigating novel methods to produce electricity in a cleaner, efficient form. Recently, Oxy-Combustion for magnetohydrodynamic power extraction has generated significant interest, since the idea was proposed as a method for clean power generation in coal and natural gas power plants. Oxy-combustion technologies have been proposed to provide high enthalpy, electrically conductive flows for direct conversion of electricity. Direct …
Design And Performance Evaluations Of A Lo2/Methane Reaction Control Engine, Aaron Johnson
Design And Performance Evaluations Of A Lo2/Methane Reaction Control Engine, Aaron Johnson
Open Access Theses & Dissertations
Liquid oxygen (LOX) and liquid methane (LCH4) are a propellant combination viewed as a potential enabling technology for spacecraft propulsion. Reasons why LOX/LCH4 is being used as an alternative propellant source include: it is less toxic than other propellants, it has the possibility to be harvested on extraterrestrial soil, LCH4 has a higher energy density than liquid hydrogen (LH2; commonly used on vehicle main engines), and LOX/LCH4 has comparable performance to other well-known propellant combinations. Through the continued partnership between the National Aeronautics and Space Administration (NASA) and the University of Texas at El Paso (UTEP) a LOX/LCH4 reaction control …
Investigation And Development Of Friction Stir Welding Process For Unreinforced Polyphenylene Sulfide And Reinforced Polyetheretherketone, Hossain Ahmed
Theses and Dissertations
The joining of thermoplastics through welding, a specific form of fusion bonding, offers numerous advantages over mechanical joining. It eliminates the use of costly fasteners and has only a limited effect on the strength of the parts being joined since it does not require the introduction of holes and loading pins, and it does not create significant stress concentrations. A specific form of welding, Friction Stir Welding, was investigated for the creation of butt joints of unreinforced polyphenylene sulfide (PPS) and short carbon fiber reinforced polyetheretherketone (PEEK) plates. Friction stir welding requires a rotating pin, a shoulder arrangement, relative movement …
Determination Of Rejected Landing Roll Runway Point-Of-No-Return And Go-Around In Transport Category Airplanes, Nihad E. Daidzic, Ph.D., Sc.D.
Determination Of Rejected Landing Roll Runway Point-Of-No-Return And Go-Around In Transport Category Airplanes, Nihad E. Daidzic, Ph.D., Sc.D.
International Journal of Aviation, Aeronautics, and Aerospace
The decelerate-accelerate-takeoff maneuver in transport category airplanes has been discussed. Mathematical model based on total energy conservation has been used to calculate the rejected landing point-of-no-return on a runway which will still enable the airplane to safely execute go-around and achieve regulatory screen heights and takeoff safety speeds. After this point has been exceeded or below the point-of-no-return speed no go-around should ever be considered. Landing long and fast and/or decelerating on slippery runways may very well result in an overrun which could be prevented if the go-around is attempted before reaching this critical runway point. The point-of-no-return on the …
An Imu-Based Spacecraft Navigation Architecture Using A Robust Multi-Sensor Fault Detection Scheme, Samuel J. Haberberger
An Imu-Based Spacecraft Navigation Architecture Using A Robust Multi-Sensor Fault Detection Scheme, Samuel J. Haberberger
Masters Theses
"Redundant sensor networks of inertial measurement units (IMUs) provide inherent robustness and redundancy to a navigation solution obtained by dead reckoning the fused accelerations and angular velocities sensed by the IMU. However, IMUs have been known to experience faults risking catastrophic mission failure creating large financial setbacks and an increased risk of human safety. Different fusion methods are analyzed for a multi-sensor network using cost effective IMUs, including direct averaging and covariance intersection. Simulations of a spacecraft in low Earth orbit are used to baseline a typical expensive IMU and compare the navigation solution obtained from a network of several …