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Articles 5521 - 5550 of 11138

Full-Text Articles in Engineering

Indoor Mapping Drone, Benjamin J. Plevny, Andrew Armstrong, Miguel Lopez, Davidson Okpara Jan 2017

Indoor Mapping Drone, Benjamin J. Plevny, Andrew Armstrong, Miguel Lopez, Davidson Okpara

Williams Honors College, Honors Research Projects

This project addresses the need for an autonomous indoor mapping system that will create a 3D map of an unknown physical environment in real time. The aerial system moves and avoids obstacles autonomously, without the need for human remote control or observation. An aerial system produces a map of an unknown indoor environment by transmitting data received from the aerial device’s sensors. The transmission occurs over a wireless channel from the aerial device to a remote server for processing and storage of the data. As the transmission is done in real time, the aerial system does not require hardware for …


System Identification Of A Circulation Control Unmanned Aerial Vehicle, Mohammed Agha Jan 2017

System Identification Of A Circulation Control Unmanned Aerial Vehicle, Mohammed Agha

Electronic Theses and Dissertations

The advancement in automation and sensory systems in recent years has led to an increase the demand of UAV missions. Due to this increase in demand, the research community has gained interest in investigating UAV performance enhancing systems. Circulation Control (CC), which is an active control flow method used to enhance UAV lift, is a performance enhancing system currently studied. In prior research, experimental studies have shown that Circulation Control wings (CCW) implemented on class-I UAVs can reduce take-off distance by 54%. Wind tunnel tests reveal that CC improves aircraft payload capabilities through lift enhancement. Increasing aircraft payload capabilities causes …


Rlc Circuit Simulated Response For Pulsed-Power Fusion Propulsion, Coleton Cody Jan 2017

Rlc Circuit Simulated Response For Pulsed-Power Fusion Propulsion, Coleton Cody

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.


Building Miniature-Sized Ion Thruster Using Split Ring Resonator (Srr), Toyofumi Yamaguchi Jan 2017

Building Miniature-Sized Ion Thruster Using Split Ring Resonator (Srr), Toyofumi Yamaguchi

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.


Lehmier Launch System, Dylan Lehmier 5248813 Jan 2017

Lehmier Launch System, Dylan Lehmier 5248813

Williams Honors College, Honors Research Projects

The Lehmier Launch System was designed to propel a 120lb rocket 30,000 feet. Creating 2150 psi of thrust and 27,500 N-s of total impulse, it is the largest rocket motor ever used by the Akronauts Rocket Design Team.


The Experimental Determination Of The Moment Of Inertia Of A Model Airplane, Michael Koken Jan 2017

The Experimental Determination Of The Moment Of Inertia Of A Model Airplane, Michael Koken

Williams Honors College, Honors Research Projects

The objective of this project is to suggest that the moment of inertia for irregular shaped objects can easily be determined experimentally. The objects considered in this experiment were a solid wooden block and a model airplane. To ensure that the method and configuration is sufficient a wooden block with known moments of inertia was first tested, and the results from the experiment were compared to the known and accepted values. For this particular experiment, the periods were determined by timing how long 10 oscillations lasted for 10 different trials, and then taking the average of those 10 trials to …


Intercomparison Of Modis And Viirs Fire Products In Khanty-Mansiysk Russia: Implications For Characterizing Gas Flaring From Space, Ambrish Sharma, Jun Wang, Elizabeth M. Lennartson Jan 2017

Intercomparison Of Modis And Viirs Fire Products In Khanty-Mansiysk Russia: Implications For Characterizing Gas Flaring From Space, Ambrish Sharma, Jun Wang, Elizabeth M. Lennartson

Department of Earth and Atmospheric Sciences: Faculty Publications

Gas flaring is commonly used by industrial plants for processing oil and natural gases in the atmosphere, and hence is an important anthropogenic source for various pollutants including CO2, CO, and aerosols. This study evaluates the feasibility of using satellite data to characterize gas flaring from space by focusing on the Khanty-Mansiysk Autonomous Okrug in Russia, a region that is well known for its dominant gas flaring activities. Multiple satellite-based thermal anomaly data products at night are intercompared and analyzed, including MODIS (Moderate Resolution Imaging Spectroradiometer) Terra level 2 Thermal Anomalies product (MOD14), MODIS Aqua level 2 Thermal …


Iris: Deep Space Small Satellite Radio, Space Dynamics Laboratory Jan 2017

Iris: Deep Space Small Satellite Radio, Space Dynamics Laboratory

Space Dynamics Laboratory Publications

With nanosatellites being used for deep space missions, the need for a unique communications architecture to relay valuable mission data back to NASA’s Deep Space Network (DSN) is vital.


Ground Segment: Solutions, Space Dynamics Laboratory Jan 2017

Ground Segment: Solutions, Space Dynamics Laboratory

Space Dynamics Laboratory Publications

SDL is a one-stop-shop for overhead and airborne ground systems and specializes in agile and flexible customized solutions. SDL’s solutions are Government owned with Government purpose rights. SDL has the facilities and staff to provide both unclassified and classified solutions.


Pearl: Spacecraft Platform, Space Dynamics Laboratory Jan 2017

Pearl: Spacecraft Platform, Space Dynamics Laboratory

Space Dynamics Laboratory Publications

SDL’s Pearl spacecraft platform delivers the performance, reliability, and mission flexibility needed for demanding small satellite missions. The Pearl platform architecture draws from common sets of components to build 3U, 6U, 12U, and custom sizes with variations in mission capability, parts quality, and radiation tolerance. This flexibility enables our professional staff to develop systems specific to each mission while drawing on a common design to maintain reliability and costs.


Relative Orbital Motion Dynamics With Respect To A Rotating Spacecraft-Fixed Frame, Nicholas Ortolano, David K. Geller, Aaron Avery Jan 2017

Relative Orbital Motion Dynamics With Respect To A Rotating Spacecraft-Fixed Frame, Nicholas Ortolano, David K. Geller, Aaron Avery

Space Dynamics Laboratory Publications

The Clohessy-Wiltshire equations are commonly used to describe the relative orbit motion of two spacecraft in proximity to each other. The relative motion solution provided by these equations is most naturally given in a local-vertical, local horizontal frame. However, if a nearby spacecraft is spinning in a controlled or uncontrolled manner, it may be more convenient to describe the relative orbital motion in the rotating spacecraft-fixed frame. This may be especially true for satellite inspection or approach to a spinning spacecraft. In this paper a set of linear-time-varying differential equations describing the orbital relative motion of two spacecraft as observed …


Nova Test Facility: Nanosat Operation Verification & Assessment Test Facility, Space Dynamics Laboratory Jan 2017

Nova Test Facility: Nanosat Operation Verification & Assessment Test Facility, Space Dynamics Laboratory

Space Dynamics Laboratory Publications

The Space Dynamics Laboratory’s (SDL) advanced NOVA test facility characterizes and verifies subsystem and system performance of small satellites up to 12 kg. The NOVA test facility provides testing to reduce preflight risk and verify requirements and is designed specifically for CubeSat-sized components and systems. NOVA augments SDL’s manufacturing, environmental testing, and calibration facilities, offering comprehensive testing capabilities and expertise for this class of small satellites.


Cadet: Uhf & Uhf Plus S-Band Radios, Space Dynamics Laboratory Jan 2017

Cadet: Uhf & Uhf Plus S-Band Radios, Space Dynamics Laboratory

Space Dynamics Laboratory Publications

With the increase in Government-funded and industry small satellites missions, the need for a more robust communication infrastructure is critical for the CubeSat community. As part of the solution, SDL provides the Cadet U and Cadet PLUS radios as powerful communications tools ideal for small satellites. These affordable solutions are available in both UHF (Cadet U) and UHF plus S-Band (Cadet PLUS) configurations. The Cadet radios are compact, power efficient, high data rate transceivers. SDL optimized the design, from the electronics to the modes of operation, for low power consumption.


Fifty-Plus-Year Postflight Analysis Of First Fluid Experiment Aboard A Spacecraft, Mark M. Weislogel, Yongkang Chen, William J. Masica, Fred J. Kohl, Robert D. Green Jan 2017

Fifty-Plus-Year Postflight Analysis Of First Fluid Experiment Aboard A Spacecraft, Mark M. Weislogel, Yongkang Chen, William J. Masica, Fred J. Kohl, Robert D. Green

Mechanical and Materials Engineering Faculty Publications and Presentations

This year marks the 55th anniversary of the first fluid physics experiment performed aboard a spacecraft during the Mercury-Atlas 7 mission. Since then, NASA has conducted over 80 fluids physics experiments aboard a variety of spacecraft, many of which have enhanced the understanding of large-length-scale capillary phenomena relevant to liquid management in the weightless state. As both celebration and demonstration, the Mercury-Atlas 7 fluids experiment is revisited in light of the current understanding of large-length-scale capillary fluidics. Employing a modern numerical tool, a rich variety of experimental outcomes are discovered that were not observed during the flight experiment. Interestingly, experimental …


Theoretical Acoustic Absorber Design Approach For Lox/Lch4 Pintle Injector Rocket Engines, Jonathan Candelaria Jan 2017

Theoretical Acoustic Absorber Design Approach For Lox/Lch4 Pintle Injector Rocket Engines, Jonathan Candelaria

Open Access Theses & Dissertations

Liquid rocket engines, or LREs, have served a key role in space exploration efforts. One current effort involves the utilization of liquid oxygen (LOX) and liquid methane (LCH4) LREs to explore Mars with in-situ resource utilization for propellant production. This on-site production of propellant will allow for greater payload allocation instead of fuel to travel to the Mars surface, and refueling of propellants to travel back to Earth. More useable mass yields a greater benefit to cost ratio. The University of Texas at El Paso's (UTEP) Center for Space Exploration and Technology Research Center (cSETR) aims to further advance these …


Experimental Investigation Of Cryogenic Convection And Boiling In Traditionally And Additively Manufactured Rocket Engine Cooling Channels, Armando Sandoval Jan 2017

Experimental Investigation Of Cryogenic Convection And Boiling In Traditionally And Additively Manufactured Rocket Engine Cooling Channels, Armando Sandoval

Open Access Theses & Dissertations

The Center for Space Exploration and Technology Research at the University of Texas at El Paso, has designed, built, and optimized an experimental high heat flux test facility to investigate the heat transfer coefficient of liquid methane and other cryogenic propellants for regenerative cooled rocket engine design. The system is composed of a copper conduction based thermal concentrator that delivers heat flow into a single sub-scaled cooling channel (test article). This study focuses on optimizing this design of the high heat flux test facility to develop a more accurate method for measuring the conductive heat flow going into the cooling …


Development And Verification Of A Lab-Scale Green Propellant Hybrid Motor System, Shyamal Patel Jan 2017

Development And Verification Of A Lab-Scale Green Propellant Hybrid Motor System, Shyamal Patel

Open Access Theses & Dissertations

Hybrid rocket propulsion offers the potential to combine advantages of both solid and liquid propellant systems, but low regression rates hinder their practicality. The suggested use of hydroxylammonium nitrate (HAN) based propellants in hybrids offers the potential for developing high impulse motors with low development and production costs. In this paper, I present the development of a small-scale system used to measure the regression rate of a hybrid motor. The system can accommodate fuel grains 5 cm long with an outer diameter of 6 cm and can implement the various decomposition gases needed for HAN. The motor firings of hydroxyl …


Design Of A 2000 Lbf Lox/Lch4 Throttleable Rocket Engine For A Vertical Lander, Israel Lopez Jan 2017

Design Of A 2000 Lbf Lox/Lch4 Throttleable Rocket Engine For A Vertical Lander, Israel Lopez

Open Access Theses & Dissertations

Liquid oxygen (LOX) and liquid methane (LCH4) has been recognized as an attractive rocket propellant combination because of its in-situ resource utilization (ISRU) capabilities, namely in Mars. ISRU would allow launch vehicles to carry greater payloads and promote missions to Mars. This has led to an increasing interest to develop spacecraft technologies that employ this propellant combination.

The UTEP Center for Space Exploration and Technology Research (cSETR) has focused part of its research efforts to developing LOX/LCH4 systems. One of those projects includes the development of a vertical takeoff and landing vehicle called JANUS. This vehicle will employ a LOX/LCH4 …


Design And Development Of A Delivery System For Green Ionic Monopropellants And Testing Of A 22n Thruster, Jaclyn Mona Mejia Jan 2017

Design And Development Of A Delivery System For Green Ionic Monopropellants And Testing Of A 22n Thruster, Jaclyn Mona Mejia

Open Access Theses & Dissertations

LMP-103S and AFM-315E are emerging propellants that are less toxic to the environment than the propellants currently being used in spacecraft propulsion. Both propellants are a blend of liquid fuel, oxidizer and a majority percent of water. The diluted solutions enable the capability to handle and store the propellants with fewer requirements; for this reason, it decreases the overall cost of the propellants since it needs less precautions. The Missile Defense Agency (MDA) awarded the University of Texas at El Paso (UTEP) a contract to further research green propellants and eventually replace Hydrazide.


Development And Integration Of The Janus Robotic Lander: A Liquid Oxygen - Liquid Methane Propulsion System Testbed, Raul Ponce Jan 2017

Development And Integration Of The Janus Robotic Lander: A Liquid Oxygen - Liquid Methane Propulsion System Testbed, Raul Ponce

Open Access Theses & Dissertations

Initiatives have emerged with the goal of sending humans to other places in our solar system. New technologies are being developed that will allow for more efficient space systems to transport future astronauts. One of those technologies is the implementation of propulsion systems that use liquid oxygen and liquid methane (LO2-LCH4) as propellants.

The benefits of a LO2-LCH4 propulsion system are plenty. One of the main advantages is the possibility of manufacturing the propellants at the destination body. A space vehicle which relies solely on liquid oxygen and liquid methane for its main propulsion and reaction control engines is necessary …


Quasi-Static Fracture Toughness Testing Of 7075 Aluminum For Spacecraft Separation Joint Applications, Ilse Alcantara Jan 2017

Quasi-Static Fracture Toughness Testing Of 7075 Aluminum For Spacecraft Separation Joint Applications, Ilse Alcantara

Open Access Theses & Dissertations

Separation joint systems are zero fault tolerant systems that have been used in complex aerospace applications such as vehicle stage separation and payload fairing removal. The structural members of separation joint systems must be able to withstand flight loads, but then completely fracture for instantaneous separation when an explosive is activated. The complex geometry and loading conditions of the structural member create a complicated stress state consisting of mixed tension and shear. A need exists to measure the fracture toughness of the material to ensure it will not support loads intended to fracture and measure its sensitivity to other variables, …


Quantifying The Characteristic Length Of A Combustor For An Ionic Liquid Monopropellant Thruster, Kimberly Marie Hogge Jan 2017

Quantifying The Characteristic Length Of A Combustor For An Ionic Liquid Monopropellant Thruster, Kimberly Marie Hogge

Open Access Theses & Dissertations

Ionic liquid monopropellants are currently being researched as a promising alternative to hydrazine in propulsion systems. This report presents a flame study that delineates the flame length of the expected decomposition products from an ionic liquid monopropellant. Through these studies, the characteristic length of a combustion chamber will be defined through calculations and empirical correlations. There is limited information on designing a propulsion system for an ionic liquid monopropellant. Therefore, defining the magnitude for an effective characteristic length serves as beneficial in designing a propulsion system for an ionic liquid monopropellant thruster.


Variable Structure Feedback Control With Application To Spacecraft With Small Thrust Propulsion Systems, Samuel J. Kitchen-Mckinley Jan 2017

Variable Structure Feedback Control With Application To Spacecraft With Small Thrust Propulsion Systems, Samuel J. Kitchen-Mckinley

Doctoral Dissertations and Master's Theses

Small spacecrafts requiring small propulsion systems are becoming more popular for low Earth orbit. It is important for these research satellites to have accurate guidance and control systems. Small propulsion systems will also be beneficial for multiple small spacecrafts used future exploration expeditions beyond low Earth orbit. These small spacecrafts benefit from the simplicity of low thrust cold gas propulsion systems. Additionally, large spacecrafts using low thrust, high specific impulse propellants for main propulsion systems, such as ion engines, allow longer and more flexible missions, including Earth orbiting spacecraft and interplanetary spacecraft.

In order to extend the life of future …


Multi-Site Simultaneous Time-Resolved Photometry With A Low Cost Electro-Optics System, Forrest Gasdia, Aroh Barjatya, Sergei Bilardi Jan 2017

Multi-Site Simultaneous Time-Resolved Photometry With A Low Cost Electro-Optics System, Forrest Gasdia, Aroh Barjatya, Sergei Bilardi

Publications

Sunlight reflected off of resident space objects can be used as an optical signal for astrometric orbit determination and for deducing geometric information about the object. With the increasing population of small satellites and debris in low Earth orbit, photometry is a powerful tool in operational support of space missions, whether for anomaly resolution or object identification. To accurately determine size, shape, spin rate, status of deployables, or attitude information of an unresolved resident space object, multi-hertz sample rate photometry is required to capture the relatively rapid changes in brightness that these objects can exhibit. OSCOM, which stands for Optical …


Modeling Of Tow Wrinkling In Automated Fiber Placement Based On Geometrical Considerations, Roudy Wehbe Jan 2017

Modeling Of Tow Wrinkling In Automated Fiber Placement Based On Geometrical Considerations, Roudy Wehbe

Theses and Dissertations

Automated manufacturing of fiber reinforced composite structures via numerically controlled hardware yields parts with increased accuracy and repeatability as compared to hand-layup parts. Automated fiber placement (AFP) is one such process in which structures or parts are built by adding bands of prescribed number of tows or slit-tape with prescribed width using robotic machine heads over 3D surfaces following prescribed paths. Despite the improved accuracy, different types of defects or manufacturing features arise during fabrication. These defects can be due to geometrical features, materials, and process planning parameters and are detected in the form of wrinkling, tow twist, tow folding, …


Finding The Balance Between Price And Protection: Establishing A Surface-To-Air Fire Risk-Reduction Training Policy For Air-Carrier Pilots, Earl W. Burress Jr. Jan 2017

Finding The Balance Between Price And Protection: Establishing A Surface-To-Air Fire Risk-Reduction Training Policy For Air-Carrier Pilots, Earl W. Burress Jr.

Journal of Aviation/Aerospace Education & Research

Currently, U.S. air carriers do not provide equipment or training necessary to mitigate the risk posed by surface-to-air fire (SAFIRE) threats. These threats consist of self-guided weapons (infrared shoulder-fired surface-to-air missiles), manually-aimed threats (small arms, recoilless grenade launchers, rockets, and light anti-aircraft artillery), and hand-held lasers. Technological solutions to counter infrared shoulder-fired missiles have been explored, but were rejected due to prohibitive equipment and maintenance costs. A lower cost option, providing air-carrier pilots with SAFIRE risk-reduction training, has not been formally addressed by the air-carrier industry or the U.S. federal government. This effort will use a business concept, the Cost-Benefit …


Liquid Pulsed Plasma Thruster Plasma Plume Investigation And Mr-Sat Cold Gas Propulsion System Performance Analysis, Jeremiah Daniel Hanna Jan 2017

Liquid Pulsed Plasma Thruster Plasma Plume Investigation And Mr-Sat Cold Gas Propulsion System Performance Analysis, Jeremiah Daniel Hanna

Masters Theses

"The plasma plume produced by a liquid pulsed plasma thruster is investigated using a Langmuir triple probe and a nude Faraday probe. The Langmuir triple probe failed to produce results which are suspected caused by the presence of ionic liquid in the plume resulting in shorting of the probe. The nude Faraday probe is able to record the ion current density which revealed a high level of inconsistency in the plasma plume. Ion current density recorded by the nude Faraday probe had a relative standard deviation of upwards of 100% of the mean value. Controlling the amount of propellant used …


Entropy-Based Performance Analysis Of Jet Engines; Methodology And Application To A Generic Single-Spool Turbojet, Mohammad Abbas Jan 2017

Entropy-Based Performance Analysis Of Jet Engines; Methodology And Application To A Generic Single-Spool Turbojet, Mohammad Abbas

Masters Theses

"Recently developed methodology that provides the direct assessment of traditional thrust-based performance of aerospace vehicles in terms of entropy generation (i.e., exergy destruction) is modified for stand-alone jet engines. This methodology is applied to a specific single-spool turbojet engine configuration. A generic compressor performance map along with modeled engine component performance characterizations are utilized in order to provide comprehensive traditional engine performance results (engine thrust, mass capture, and RPM), for on and off-design engine operation. Details of exergy losses in engine components, across the entire engine, and in the engine wake are provided and the engine performance losses associated with …


Development And Implementation Of Star Tracker Based Attitude Determination, Casey Grant Smith Jan 2017

Development And Implementation Of Star Tracker Based Attitude Determination, Casey Grant Smith

Masters Theses

"As interest in nanosatellites grows within the university community, the demand for inexpensive, space-grade hardware grows as well. Star trackers can be a luxury item for some spacecraft and therefore are often not considered due to their cost. Ideally, a star tracker could be built using inexpensive parts so long as the software is available. Unlike many other attitude determination instruments, star trackers are renowned for their high accuracy, yielding accurate and precise attitude estimates. However, development of this software can be overwhelming for the university settling, especially when multiple missions are on hand. If these instruments were readily available …


Probabilistic Analysis And Verification Framework For Adaptive Flight Control, Mario Luca Fravolini, Tansel Yucelen, Marcello Napolitano Jan 2017

Probabilistic Analysis And Verification Framework For Adaptive Flight Control, Mario Luca Fravolini, Tansel Yucelen, Marcello Napolitano

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A crucial aspect that could facilitate the applications of adaptive control systems in aerospace applications is the development of effective validation and verification procedures. Most of the existing analysis and design frameworks for adaptive controllers are based on the Lyapunov direct method. One well-known drawback of this approach is the conservatism in the estimation of the uniform ultimate boundedness region with little practical utility. To overcome this limitation, a probabilistic framework for the design of uniform ultimate boundedness regions is proposed where uncertain parameters and adaptive controls are considered as random variables. In this framework, the design is translated into …