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Aerospace Engineering Commons

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2005

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Articles 151 - 160 of 160

Full-Text Articles in Aerospace Engineering

The Katysat Project: Kids Aren’T Too Young (For Satellites), Benjamin Yuan Jan 2005

The Katysat Project: Kids Aren’T Too Young (For Satellites), Benjamin Yuan

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Benjamin Yuan titled "The KatySat Project: Kids Aren’t Too Young (for satellites)" from April 14, 2005.


Results Of An Interlaboratory Study Of The Astm Standard Test Method For Tensile Properties Of Polymer Matrix Composites D 3039, Margaret Pinnell, Richard Fields, Ronald Zabora Jan 2005

Results Of An Interlaboratory Study Of The Astm Standard Test Method For Tensile Properties Of Polymer Matrix Composites D 3039, Margaret Pinnell, Richard Fields, Ronald Zabora

Mechanical and Aerospace Engineering Faculty Publications

An investigation was conducted on the ASTM Standard Test Method for Tensile Properties of Polymer Matrix Composites (D 3039). This investigation consisted of both preliminary testing and an interlaboratory test program. Information generated from preliminary testing was used to determine the effects of various parameters and to optimize the interlaboratory test plan and test protocol. The interlaboratory study portion of this investigation was conducted on six composite material systems in a variety of lay-up configurations. The number of participating labs ranged from five to nine depending on the material type. Precision statistics were determined for the ASTM D 3039 standard …


Measurement And Control Of Torque Ripple-Induced Frame Torsional Vibration In A Surface Mount Permanent Magnet Machine, Jason Neely, Steven Pekarek, Daniel S. Stutts, Philip Beccue Jan 2005

Measurement And Control Of Torque Ripple-Induced Frame Torsional Vibration In A Surface Mount Permanent Magnet Machine, Jason Neely, Steven Pekarek, Daniel S. Stutts, Philip Beccue

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A sensor to measure the stator torsional vibration due to torque ripple produced by a surface mount permanent magnet machine is first described. The sensor is relatively inexpensive and is straight forward to incorporate into a drive system. Experiments are performed to validate that the voltage produced by the sensor is linearly related to torque ripple amplitude. Closed-loop controllers are then described that adjust the stator current harmonics applied to the machine to achieve a commanded average torque while mitigating measured torsional vibration. Simulation and experimental results are used to demonstrate the effectiveness of the control techniques.


Analysis And Modeling Of Information Flow And Distributed Expertise In Space-Related Operations, Barrett S. Caldwell Jan 2005

Analysis And Modeling Of Information Flow And Distributed Expertise In Space-Related Operations, Barrett S. Caldwell

School of Industrial Engineering Faculty Publications

Evolving space operations requirements and mission planning for long-duration expeditions require detailed examinationsand evaluations of information flow dynamics, knowledge-sharing processes, and information technology use in distributedexpert networks. This paper describes the work conducted with flight controllers in the Mission Control Center (MCC) ofNASA’s Johnson Space Center. This MCC work describes the behavior of experts in a distributed supervisory coordinationframework, which extends supervisory control/command and control models of human task performance. Findings from thiswork are helping to develop analysis techniques, information architectures, and system simulation capabilities for knowledgesharing in an expert community. These findings are being applied to improve knowledge-sharing processes …


Modeling Satellite Formations In The Presence Of Perturbations, Robert Cannaday Jan 2005

Modeling Satellite Formations In The Presence Of Perturbations, Robert Cannaday

Electronic Theses and Dissertations

The potential benefits of autonomous satellite formation flying in such areas as high- resolution remote sensing, and sparse aperture radar, has stimulated interest in modeling the satellite environment for feasibility and simulation studies to help explore and define the technical challenges that must be solved in order to achieve successful autonomous satellite formations. The purpose of this paper is to develop and describe a numerical simulation of the orbital environment including central force field perturbations and atmospheric drag effects which will be a useful analytical tool for investigating issues relating to maintaining satellite formations in low-earth-orbit. Many of the studies …


Nonlinear Flutter Of Curved Panels Under Yawed Supersonic Flow Using Finite Elements, Mohamed Salim Azzouz Jan 2005

Nonlinear Flutter Of Curved Panels Under Yawed Supersonic Flow Using Finite Elements, Mohamed Salim Azzouz

Mechanical & Aerospace Engineering Theses & Dissertations

In the extensive published literature on panel flutter, a large number of papers are dedicated to investigation of flat plates in the supersonic flow regime. Very few authors have extended their work to flutter of curved panels. The curved geometry generates a pre-flutter behavior, triggering a static deflection due to a static aerodynamic load (SAL) over the panel as well as dynamic characteristics unique to this geometry. The purpose of this dissertation is to provide new insights in the subject of flutter of curved panels. Finite element frequency and time domain methods are developed to predict the pre/post flutter responses …


Accuracy Of Heat-Pulse Sensors For Determining Moisture Of Capillary Mat Material Used To Support Plant Growth, Marisa Wyssling Jan 2005

Accuracy Of Heat-Pulse Sensors For Determining Moisture Of Capillary Mat Material Used To Support Plant Growth, Marisa Wyssling

Master's Theses - Daytona Beach

The accuracy and precision of Orbital Technologies (Orbitec, Madison, WI) Thermal and Moisture Acquisition System (TMAS) sensors were investigated for use in the WONDER space flight experiment. WONDER is studying the effect of multiple wetness level regimes and two different nutrient delivery systems (NDS) on plants grown in the microgravity of space. The following research concentrates on the porous tube NDS consisting solely of a capillary mat surrounding a bare porous tube used for water delivery. Sensors and plants will be attached to the capillary mat, which transports water by capillary action. The TMAS sensors, single probe heat-pulse moisture sensors, …


Incorporating The Impact Of Engineering Solutions On Society Into Technical Engineering Courses, Nicole Dejong-Okamoto, Jinny Rhee, Nikos J. Mourtos Jan 2005

Incorporating The Impact Of Engineering Solutions On Society Into Technical Engineering Courses, Nicole Dejong-Okamoto, Jinny Rhee, Nikos J. Mourtos

Faculty Publications

In the era of market and workforce globalisation, engineers need a solid understanding of the impact that their products have locally, as well as globally. This is why the US Accreditation Board for Engineering and Technology (ABET) recently put a new spin on this requirement in engineering education. Specifically, outcome 3h of Engineering Criteria 2000 states that engineering graduates must have the broad education to understand the impact of engineering solutions in a global/ societal context. This outcome may be one of the most difficult to achieve, since it requires not only a strong technical understanding, but also an informed …


Seed Storage Reserves And Glucosinolates In Brassica Rapa L. Grown On The International Space Station, M. E. Musgrave, Anxiu Kuang, L. K. Tuominen, L. H. Levine, R. C. Morrow Jan 2005

Seed Storage Reserves And Glucosinolates In Brassica Rapa L. Grown On The International Space Station, M. E. Musgrave, Anxiu Kuang, L. K. Tuominen, L. H. Levine, R. C. Morrow

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Although plants are envisioned to play a central role in life support systems for future long-duration space travel, plant growth in space has been problematic due to horticultural problems of nutrient delivery and gas resupply posed by the weightless environment. Iterative improvement in hardware designed for growth of plants on orbital platforms now provides confidence that plants can perform well in microgravity, enabling investigation of their nutritional characteristics. Plants of B. rapa (cv. Astroplants) were grown in the Biomass Production System on the International Space Station. Flowers were hand-pollinated and seeds were produced prior to harvest at 39 days after …


Performance Analysis And Validation Of A Recoverable Flight Control System In A Simulated Neutron Environment, Hong Zhang, W. Steven Gray, Oscar R. Gonzalez Jan 2005

Performance Analysis And Validation Of A Recoverable Flight Control System In A Simulated Neutron Environment, Hong Zhang, W. Steven Gray, Oscar R. Gonzalez

Electrical & Computer Engineering Faculty Publications

This paper introduces a class of stochastic hybrid models for the analysis of closed-loop control systems implemented with NASA's Recoverable Computer System. Such Recoverable Computer Systems have been proposed to insure reliable control performance in harsh environments. The stochastic hybrid models consist of either a stochastic finite-state automaton or a finite-state machine driven by a Markov input, which in turn drives a switched linear discrete-time dynamical system. Their stability and output tracking performance are analyzed using an extension of the existing theory for Markov jump-linear systems. For illustration, a stochastic hybrid model is used to calculate the tracking error performance …