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Numerical Investigation Of Aeroelastic Mode Distribution For Aircraft Wing Model In Subsonic Air Flow, Marianna A. Shubov, Stephen B. Wineberg, Robert Holt 2010 University of New Hampshire

Numerical Investigation Of Aeroelastic Mode Distribution For Aircraft Wing Model In Subsonic Air Flow, Marianna A. Shubov, Stephen B. Wineberg, Robert Holt

Mathematics & Statistics Scholarship

In this paper, the numerical results on two problems originated in aircraft wing modeling have been presented. The first problem is concerned with the approximation to the set of the aeroelastic modes, which are the eigenvalues of a certain boundary-value problem. The affirmative answer is given to the following question: can the leading asymptotical terms in the analytical formulas be used as reasonably accurate description of the aeroelastic modes? The positive answer means that these leading terms can be used by engineers for practical calculations. The second problem is concerned with the flutter phenomena in aircraft wings in a subsonic ...


Compact Survey And Inspection Day/Night Image Sensor Suite For Small Unmanned Aircraft Systems (Eyepod), Alan Bird, Scott A. Anderson, Dale Linne von Berg, Morgan Davidson, Niel Holt, Melvin Kruer, Michael L. Wilson 2010 Utah State University

Compact Survey And Inspection Day/Night Image Sensor Suite For Small Unmanned Aircraft Systems (Eyepod), Alan Bird, Scott A. Anderson, Dale Linne Von Berg, Morgan Davidson, Niel Holt, Melvin Kruer, Michael L. Wilson

Space Dynamics Lab Publications

EyePod is a compact survey and inspection day/night imaging sensor suite for small unmanned aircraft systems (UAS). EyePod generates georeferenced image products in real-time from visible near infrared (VNIR) and long wave infrared (LWIR) imaging sensors and was developed under the ONR funded FEATHAR (Fusion, Exploitation, Algorithms, and Targeting for High-Altitude Reconnaissance) program. FEATHAR is being directed and executed by the Naval Research Laboratory (NRL) in conjunction with the Space Dynamics Laboratory (SDL) and FEATHAR’s goal is to develop and test new tactical sensor systems specifically designed for small manned and unmanned platforms (payload weight < 50 lbs). The EyePod suite consists of two VNIR/LWIR (day/night) gimbaled sensors that, combined, provide broad area survey and focused inspection capabilities. Each EyePod sensor pairs an HD visible EO sensor with a LWIR bolometric imager providing precision geo-referenced and fully digital EO/IR NITFS output imagery. The LWIR sensor is mounted to a patent-pending jitter-reduction stage to correct for the high-frequency motion typically found on small aircraft and unmanned systems. Details will be presented on both the wide-area and inspection EyePod sensor systems, their modes of operation, and results from recent flight demonstrations.


Pilot Source Study: An Analysis Of Pilot Backgrounds And Subsequent Success In Us Regional Airline Training Programs, Guy M. Smith, David A. NewMyer, Elizabeth Bjerke, Mary Niemczyk, Raymond A. Hamilton 2010 Embry Riddle Aeronautical University

Pilot Source Study: An Analysis Of Pilot Backgrounds And Subsequent Success In Us Regional Airline Training Programs, Guy M. Smith, David A. Newmyer, Elizabeth Bjerke, Mary Niemczyk, Raymond A. Hamilton

Applied Aviation Sciences - Daytona Beach

The 2010 Pilot Source Study, commissioned to research the success of pilots in initial training for Part 121 operations, analyzed the training performance of 2,156 new-hire pilots in the years 2005-2009. Six regional airlines provided data that was mined from human resource and pilot training files. Five university researchers independently analyzed the data and integrated their results. The study expressed success in terms of fewer extra training events and fewer non-completions in regional airline training. Statistically, the best performing pilots were those who had flight instructor certificates, graduated from collegiate accredited flight programs, received advanced (post-Private) pilot training in ...


Mixi Thruster Tungsten And Thoriated Tungsten Testing, Jesse R. Miller 2010 California Polytechnic State University - San Luis Obispo

Mixi Thruster Tungsten And Thoriated Tungsten Testing, Jesse R. Miller

Aerospace Engineering

The purpose of this project is to build and evaluate a tungsten filament cathode for the 3-cm Miniature Xenon Ion (MiXI) thruster. The filament is to be used for future tests within the CP 3-cm MiXI and thoriated tungsten is to be examined as a possible alternative. No testing of these filaments was conducted, but the preparatory work has been conducted for future testing.


Simulations Of Flow Over Wind Turbines, Dnyanesh A. Digraskar 2010 University of Massachusetts Amherst

Simulations Of Flow Over Wind Turbines, Dnyanesh A. Digraskar

Masters Theses 1911 - February 2014

One of the most abundant sources of renewable energy is wind. Today, a considerable amount of resources are being utilized for research on harnessing the wind energy efficiently. Out of all the factors responsible for efficient energy production, the aerodynamics of flow around the wind turbine blades play an important role. This work aims to undertake aerodynamic analysis of a Horizontal Axis Wind Turbine. A steady state, incompressible flow solver for multiple reference frames, MRFSimple- Foam is modified and used for performing simulations of flow over National Renewable Energy Laboratory Phase VI wind turbine rotor. The code is first tested ...


Analysis Of The Theta-D Filter As Applied To Hit-To-Kill Interceptors And Satellite Orbit Determination, Michael W. Dancer 2010 Missouri University of Science and Technology

Analysis Of The Theta-D Filter As Applied To Hit-To-Kill Interceptors And Satellite Orbit Determination, Michael W. Dancer

Masters Theses

"When designing feedback control systems, there is often a need for estimation methods that provide system information that is not readily available via sensors placed within the system. In many cases a sensor that measures a particular system state either does not exist or is prohibitively expensive. In addition, all realistic systems contain some degree of nonlinearity. This thesis focuses on two such cases: missile guidance with bearings-only measurements and GPS satellite orbit determination. In each case, a new nonlinear filter, the [theta]-D method, is used and evaluated for its performance in providing the necessary estimation. To aid the ...


Integration And Test Of A Refrigerant-Based Cold-Gas Propulsion System For Small Satellites, Ryan Alan Pahl 2010 Missouri University of Science and Technology

Integration And Test Of A Refrigerant-Based Cold-Gas Propulsion System For Small Satellites, Ryan Alan Pahl

Masters Theses

"Due to the launch safety constraints placed on university-built small satellites, designing a low-cost propulsion system to meet mission requirements presents a significant challenge to aspiring student engineers. The Missouri University of Science and Technology is currently developing a low-cost, two-phase propulsion system using the refrigerant R-134a as the propellant that can be stored at low pressures while still providing sufficient performance to meet mission goals. The purpose of this study is to present the testing results of a refrigerant-based cold gas system utilizing R-134a as a saturated liquid propellant and the ability to design this system to be portable ...


Orbit Options For An Orion-Class Spacecraft Mission To A Near-Earth Object, Nathan C. Shupe 2010 University of Colorado at Boulder

Orbit Options For An Orion-Class Spacecraft Mission To A Near-Earth Object, Nathan C. Shupe

Aerospace Engineering Sciences Graduate Theses & Dissertations

Based on the recommendations of the Augustine Commission, President Obama has proposed a vision for U.S. human spaceflight in the post-Shuttle era which includes a manned mission to a Near-Earth Object (NEO). A 2006-2007 study commissioned by the Constellation Program Advanced Projects Office investigated the feasibility of sending a crewed Orion spacecraft to a NEO using different combinations of elements from the latest launch system architecture at that time. The study found a number of suitable mission targets in the database of known NEOs, and predicted that the number of candidate NEOs will continue to increase as more advanced ...


Finite Element Modeling And Optimization Of High-Speed Aerothermoelastic Systems, Micah A. Howard 2010 University of Colorado at Boulder

Finite Element Modeling And Optimization Of High-Speed Aerothermoelastic Systems, Micah A. Howard

Aerospace Engineering Sciences Graduate Theses & Dissertations

The design of supersonic and hypersonic aerospace vehicles is by nature a multi-disciplinary problem requiring the close integration of compressible fluid dynamics, heat transfer, and structural dynamics. The transient flow around the body must be accurately characterized in order to assess its effect on the thermal and structural responses; conversely, the thermal and structural behavior may significantly alter the aerodynamic performance. The core of this dissertation effort is concerned with the development and demonstration of an analysis and design capability for the aerothermoelastic behavior of high-speed aerospace vehicles. This nominally involves coupling of the compressible Navier-Stokes equations for the fluid ...


Assessing Feasibility Of Electrochromic Space Suit Radiators For Reducing Extravehicular Activity Water Consumption, Jonathan Glen Metts 2010 University of Colorado at Boulder

Assessing Feasibility Of Electrochromic Space Suit Radiators For Reducing Extravehicular Activity Water Consumption, Jonathan Glen Metts

Aerospace Engineering Sciences Graduate Theses & Dissertations

Water consumption for space suit thermal control is a limiting factor on long-term space exploration missions. A concept is proposed for an integrated, flexible suit radiator using infrared electrochromic materials for modulated heat rejection from the suit. Properties of electrochromic materials, the structure of electrochromic devices, and relevant heat transfer processes are presented as background information. Analytical methods are employed to bound theoretical performance and determine required emissivity ranges for lunar surface operations. Case studies are presented incorporating Apollo program and Advanced Walkback Test metabolic and environmental data to estimate sublimator water consumption and hypothetical water savings with the electrochromic ...


Laminar-Turbulent Transition For Attached And Separated Flow, Qian Zhang 2010 University of Kentucky

Laminar-Turbulent Transition For Attached And Separated Flow, Qian Zhang

University of Kentucky Doctoral Dissertations

A major challenge in the design of turbomachinery components for aircraft gas turbine engines is high cycle fatigue failures due to flutter. Of particular concern is the subsonic/transonic stall flutter boundary which occurs at part speed near the stall line. At these operating conditions the incidence angle is large and the relative Mach number is high subsonic or transonic. Viscous effects dominate for high incidence angles.

In order to predict the flutter phenomena, accurate calculation of the steady and unsteady aerodynamic loading on the turbomachinery airfoils is necessary. The development of unsteady aerodynamic models to predict the unsteady forces ...


Real-Time On-Board Object Tracking For Cooperative Flight Control, Ajay Kumar Mandava, Emma Regentova, Henry Selvaraj 2010 University of Nevada, Las Vegas

Real-Time On-Board Object Tracking For Cooperative Flight Control, Ajay Kumar Mandava, Emma Regentova, Henry Selvaraj

Electrical and Computer Engineering Faculty Publications

One of possible cooperative Situations for flights could be a scenario when the decision on a new path is taken by A Certain fleet member, who is called the leader. The update on the new path is Transmitted to the fleet members via communication That can be noisy. An optical sensor can be used as a back-up for re-estimating the path parameters based on visual information. For A Certain topology, the issue can be solved by continuous tracking of the leader of the fleet in the video sequence and re-adjusting parameters of the flight, accordingly. To solve such a problem ...


Solar Sail Attitude Dynamics And Coning Control: On Developing Control Methods For Solar Sail Coning At Orbit Rate To Attain Desired Orbital Effects, Farheen Rizvi 2010 University of Colorado at Boulder

Solar Sail Attitude Dynamics And Coning Control: On Developing Control Methods For Solar Sail Coning At Orbit Rate To Attain Desired Orbital Effects, Farheen Rizvi

Aerospace Engineering Sciences Graduate Theses & Dissertations

In this thesis, a control method is developed for the solar sail normal vector to trace a desired circular coning trajectory at orbit rate. The coning trajectory is defined in the local vertical local horizontal (LVLH) frame and the coning occurs about an LVLH equilibrium sail attitude. Past research has shown that sail attitude equilibria exist in the LVLH frame under the influence of aerodynamic, gravity gradient and solar torques. Precession of the sail normal from these equilibria causes sail normal coning about that equilibrium attitude. If the coning happens at orbit rate, wide variety of orbital effects can be ...


Two-Craft Coulomb Formation Study About Circular Orbits And Libration Points, Ravi Kishore Inampudi 2010 University of Colorado at Boulder

Two-Craft Coulomb Formation Study About Circular Orbits And Libration Points, Ravi Kishore Inampudi

Aerospace Engineering Sciences Graduate Theses & Dissertations

This dissertation investigates the dynamics and control of a two-craft Coulomb formation in circular orbits and at libration points; it addresses relative equilibria, stability and optimal reconfigurations of such formations. The relative equilibria of a two-craft tether formation connected by line-of-sight elastic forces moving in circular orbits and at libration points are investigated. In circular Earth orbits and Earth-Moon libration points, the radial, along-track, and orbit normal great circle equilibria conditions are found. An example of modeling the tether force using Coulomb force is discussed. Furthermore, the non-great-circle equilibria conditions for a two-spacecraft tether structure in circular Earth orbit and ...


Earth's Outer Radiation Belt Electrons: Identifying Sources, Improving Forecasts, And A New Particle Detector Design, Drew Lawson Turner 2010 University of Colorado, Boulder

Earth's Outer Radiation Belt Electrons: Identifying Sources, Improving Forecasts, And A New Particle Detector Design, Drew Lawson Turner

Aerospace Engineering Sciences Graduate Theses & Dissertations

Earth's outer radiation belt is a highly dynamic region composed primarily of relativistic electrons, which can pose a threat to spacecraft and astronauts. Despite decades of acquiring data and conducting research, the exact mechanisms and relative importance of outer belt electron source, loss, and transport processes are still not fully understood. Here, I follow the full cycle of outer belt electron data, from acquiring it in situ to analysis and practical use. I start by discussing a new instrument designed to measure relativistic particles from a low-cost picosatellite in low-Earth orbit, which will provide complementary data to NASA's ...


Characterizing Longitude-Dependent Orbital Debris Congestion In The Geosynchronous Orbit Regime, Paul V. Anderson 2010 University of Colorado Boulder

Characterizing Longitude-Dependent Orbital Debris Congestion In The Geosynchronous Orbit Regime, Paul V. Anderson

Aerospace Engineering Sciences Graduate Theses & Dissertations

The geosynchronous orbit (GEO) is a unique commodity of the satellite industry that is becoming increasingly contaminated with orbital debris, but is heavily populated with high-value assets from the civil, commercial, and defense sectors. The GEO arena is home to hundreds of communications, data transmission, and intelligence satellites collectively insured for an estimated 18.3 billion USD. As the lack of natural cleansing mechanisms at the GEO altitude renders the lifetimes of GEO debris essentially infinite, conjunction and risk assessment must be performed to safeguard operational assets from debris collisions.

In this thesis, longitude-dependent debris congestion is characterized by predicting ...


Multifunctional Polymer Synthesis And Incorporation Of Gadolinium Compounds And Modified Tungsten Nanoparticles For Improvement Of Radiation Shielding For Use In Outer Space, Emily Grace Harbert 2010 College of William & Mary - Arts & Sciences

Multifunctional Polymer Synthesis And Incorporation Of Gadolinium Compounds And Modified Tungsten Nanoparticles For Improvement Of Radiation Shielding For Use In Outer Space, Emily Grace Harbert

Dissertations, Theses, and Masters Projects

No abstract provided.


Gravitational Effects On Thin-Wire Subcooled Nucleate Boiling Dynamics, Justin Koeln, Andrew Fassmann, Troy Munro, Rob Barnett 2010 Utah State University

Gravitational Effects On Thin-Wire Subcooled Nucleate Boiling Dynamics, Justin Koeln, Andrew Fassmann, Troy Munro, Rob Barnett

Presentations

No abstract provided.


Studies Of Dynamic Crack Propagation And Crack Branching With Peridynamics, Youn Doh Ha Ph.D., Florin Bobaru Ph.D. 2010 University of Nebraska at Lincoln

Studies Of Dynamic Crack Propagation And Crack Branching With Peridynamics, Youn Doh Ha Ph.D., Florin Bobaru Ph.D.

Faculty Publications from the Department of Engineering Mechanics

In this paper we discuss the peridynamic analysis of dynamic crack branching in brittle materials and show results of convergence studies under uniform grid refinement (m-convergence) and under decreasing the peridynamic horizon (δ-convergence). Comparisons with experimentally obtained values are made for the crack-tip propagation speed with three different peridynamic horizons.We also analyze the influence of the particular shape of themicro-modulus function and of different materials (Duran 50 glass and soda-lime glass) on the crack propagation behavior. We show that the peridynamic solution for this problem captures all the main features, observed experimentally, of dynamic crack propagation and branching, as ...


Multiscale Modeling Of Tio2 Nanoparticle Production In Flame Reactors: Effect Of Chemical Mechanism, Maulik Mehta, Yonduck Sung, Venkatramanan Raman, Rodney O. Fox 2010 Iowa State University

Multiscale Modeling Of Tio2 Nanoparticle Production In Flame Reactors: Effect Of Chemical Mechanism, Maulik Mehta, Yonduck Sung, Venkatramanan Raman, Rodney O. Fox

Chemical and Biological Engineering Publications

For titanium dioxide (TiO2) nanoparticles manufactured in flame reactors, the precursor is injected into a pre-existing flame, exposing it to a high-temperature gas phase, leading to nucleation and particle growth. Predictive modeling of this chemical process requires simultaneous development of detailed chemical mechanisms describing gas-phase combustion and particle evolution, as well as advanced computational tools for describing the turbulent flow field and its interactions with the chemical processes. Here, a multiscale computational tool for flame-based TiO2 nanoparticle synthesis is developed and a flamelet model representing detailed chemistry for particle nucleation is proposed. The effect of different chemical mechanisms ...


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