Dynamic Modeling And Ascent Flight Control Of Ares-I Crew Launch Vehicle, 2010 Iowa State University
Dynamic Modeling And Ascent Flight Control Of Ares-I Crew Launch Vehicle, Wei Du
Graduate Theses and Dissertations
This research focuses on dynamic modeling and ascent flight control of large flexible launch vehicles such as the Ares–I Crew Launch Vehicle (CLV). A complete set of six–degrees–of–freedom dynamic models of the Ares–I, incorporating its propulsion, aerodynamics, guidance and control, and structural flexibility, is developed. NASA's Ares–I reference model and the SAVANT Simulink–based program are utilized to develop a Matlab–based simulation and linearization tool for an independent validation of the performance and stability of the ascent flight control system of large flexible launch vehicles. A linearized state–space model as well ...
Microstructure Investigation Of Al-Rich Titanium Aluminum Alloys, 2010 University of Texas at El Paso
Microstructure Investigation Of Al-Rich Titanium Aluminum Alloys, David Pham
Open Access Theses & Dissertations
The microstructures of Ti-Al alloys with 70-80 wt% Al were investigated. Aluminum wire (99.999%) and TiH2 powder (99.7%) were used to produce the sample compositions inside a vertical tube furnace at 1600oC in an Ar atmosphere. Argon is purified through a dehumidification and deoxidation system. Magnesium perchlorate Mg(ClO4)2 acts as a desiccant and titanium sponge pulls oxygen from the Ar in furnaces operating at 800oC and 750oC. X-ray diffraction and an optical microscope are used to identify phases and compositions
Development Of A Micro-Catbed For Miniature Thrusters, 2010 University of Texas at El Paso
Development Of A Micro-Catbed For Miniature Thrusters, Chance Paul Garcia
Open Access Theses & Dissertations
The goal of this work is to develop a micro catalytic bed for miniature thrusters. A test bed was constructed for experimental testing to characterize several parts of the micro catalytic bed. The reactant fluid studied is 90% Hydrogen Peroxide (H2O2) by weight. Three different cross sectional area designs were tested to determine decomposition efficiency, temperature reaction propensity, optimum flow rate, and temperature distribution across each bed. The products of decomposition were condensed to measure the oxygen released from decomposition. The results will be used to develop the basis for a micro catalytic bed design to implement into future miniature ...
Experimental Data Analysis Of The Vortex Structures In The Wakes Of Flapping Wings, 2010 Iowa State University
Experimental Data Analysis Of The Vortex Structures In The Wakes Of Flapping Wings, Kai Wang, Umesh Vaidya, Baskar Ganapathysubramanian, Hui Hu
Mechanical Engineering Conference Presentations, Papers, and Proceedings
The objective of this paper is to compare the existing methods and develop novel approaches for the experimental data analysis of the unsteady aerodynamics of the flapping wing microaerial-vehicle. These methods are developed for the purpose of identification of the beneficial dynamics and for the development of reduced order models for control design. We first employ Proper Orthogonal Decomposition (POD) method for the data analysis of the PIV measurements in the wakes of piezoelectric flapping wings. The basic idea behind POD based data analysis method is to decompose the time series snapshots of PIV measurements into high energy, POD, modes ...
Numerical Investigation Of Aeroelastic Mode Distribution For Aircraft Wing Model In Subsonic Air Flow, 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 ...
Spacecraft Coating-Induced Charging: A Materials And Modeling Study Of Environmental Extreme, 2010 Johns Hopkins University
Spacecraft Coating-Induced Charging: A Materials And Modeling Study Of Environmental Extreme, Michelle M. Donegan, Jennifer L. Sample, Jr Dennison, R. Hoffman
All Physics Faculty Publications
As mankind reaches to explore extreme environments in space, the application of ceramics surface coatings is increasing. The 2005 mission concept for Solar Probe used a unique design to achieve the necessary thermal control for a very close approach to the solar corona, including the use of a highly refractory, electrically insulating ceramic coating over a carbon-carbon composite heat shield. The proposed trajectory takes the spacecraft from a Jovian fly-by to within 4 solar radii of the Sun, spanning 5 orders of magnitude in solar radiation and solar wind plasma density as well as spacecraft temperatures from <100 K to >2000 K. Using ...100>
Pilot Source Study: An Analysis Of Pilot Backgrounds And Subsequent Success In Us Regional Airline Training Programs, 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 ...
Multifunctional Polymer Synthesis And Incorporation Of Gadolinium Compounds And Modified Tungsten Nanoparticles For Improvement Of Radiation Shielding For Use In Outer Space, 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.
Autonomous Optimal Deorbit Guidance, 2010 Iowa State University
Autonomous Optimal Deorbit Guidance, Morgan Baldwin
Graduate Theses and Dissertations
The objective of this dissertation is to solve an optimal deorbit guidance problem given initial orbit and vehicle parameters as inputs. Currently, the problem is computationally intensive to solve and approximate methods such as impulsive maneuvers are utilized. The problem is formulated as a fuel-optimal control problem that allows for a variety of terminal conditions at entry interface (EI). Using optimal control methods, the engine on time, engine off time as well as the direction of the thrust vector are solved for a variety of circular and elliptic initial orbits. Single and multiple burn maneuvers for both circular and elliptic ...
A Fast Ascent Trajectory Optimization Method For Hypersonic Air-Breathing Vehicles, 2010 Iowa State University
A Fast Ascent Trajectory Optimization Method For Hypersonic Air-Breathing Vehicles, Oscar Jaime Murillo
Graduate Theses and Dissertations
The objective of this dissertation is to investigate a fast and reliable method to generate three-dimensional optimal ascent trajectories for hypersonic air-breathing vehicles. The problem is notoriously difficult because of the strong nonlinear coupling amongst aerodynamics, propulsion, vehicle attitude and trajectory state. As such an algorithm matures, the ultimate goal is to realize optimal closed-loop ascent guidance for hypersonic air-breathing vehicles. The problem is formulated as a fuel-optimal control problem. The corresponding necessary conditions are given. It is shown how the original problem of search for the optimal control commands can be reduced to a univariate root-finding problem at each ...
Multiscale Modeling Of Tio2 Nanoparticle Production In Flame Reactors: Effect Of Chemical Mechanism, 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 ...
Experimental Study Of Inhomogeneous Deformation In Bulk Metallic Glass And Their Composite During Wedge-Like Cylindrical Indentation, Hui Wang
Graduate Theses and Dissertations
Bulk metallic glasses (BMGs) are amorphous metals with impressive mechanical properties, such as high elastic strain up to 2%, high strength (up to 2% of Young's modulus) and high hardness. Their weight normalized properties exceed the high strength to weight ratio of titanium alloys. Because of the lack of crystalline defects such as grain boundaries and dislocations, they have good corrosion resistance and good formability. The unique die molding properties of BMGs render them as excellent candidates for micro-scale machine parts, pressure sensor, golf clubs and casings. BMG's also exhibit enhanced plastic creep resistance, since homogeneous plastic deformation ...
An Uncertainty Quantification Of The Variation Of Internal Heat Transfer Coefficients And The Effect On Airfoil Life, 2010 University of Central Florida
An Uncertainty Quantification Of The Variation Of Internal Heat Transfer Coefficients And The Effect On Airfoil Life, Jan H. Marsh
Electronic Theses and Dissertations
Uncertainty in accurately knowing applied internal heat transfer coefficients inside of a cooling passage can lead to variability in predicting low cycle fatigue life of a turbine vane or blade. Under-predicting a life value for a turbine part can have disastrous effects on the engine as a whole, and can negate efforts in innovative design for advanced cooling techniques for turbine components. Quantification of this fatigue life uncertainty utilizing a computational framework is the primary objective of this thesis. Through the use of probabilistic design methodologies a process is developed to simulate uncertainties of internal heat transfer coefficient, which are ...
Integration And Test Of A Refrigerant-Based Cold-Gas Propulsion System For Small Satellites, 2010 Missouri University of Science and Technology
Integration And Test Of A Refrigerant-Based Cold-Gas Propulsion System For Small Satellites, Ryan Alan Pahl
"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 ...
Management Of A University Satellite Program With Focus On A Refrigerant-Based Propulsion System, 2010 Missouri University of Science and Technology
Management Of A University Satellite Program With Focus On A Refrigerant-Based Propulsion System, Shawn W. Miller
"The Missouri University of Science and Technology Satellite (M-SAT) design team has established a satellite program to develop a pair of satellites to perform an autonomous formation flight mission. The resulting configuration was assembled for the Air Force Research Lab University Nanosat Program. This document, written by the Program Manager and former member of the Propulsion subsystem, is a description of the management process used by the team to develop a satellite configuration. Included in the document is a discussion of team organization, techniques for managing a program, and lessons learned during the 2007 to 2008 timeframe. The managing techniques ...
Simulations Of Flow Over Wind Turbines, 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 ...
Real-Time On-Board Object Tracking For Cooperative Flight Control, 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 ...
Analysis Of The Theta-D Filter As Applied To Hit-To-Kill Interceptors And Satellite Orbit Determination, 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
"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 ...
A Numerical Investigation Of Flowfield Modification In High-Speed Airbreathing Inlets Using Energy Deposition, 2010 Missouri University of Science and Technology
A Numerical Investigation Of Flowfield Modification In High-Speed Airbreathing Inlets Using Energy Deposition, Matthew Flynn Rohweder
"Energy deposition in front of dual-mode ram/scramjet engines is numerically investigated utilizing two-dimensional CFD for its potential to modify inlet/isolator flow-fields for engine start/unstart control and for its general potential for generating large-scale flow-field modification in such flows. A simplified (high Mach number) constant-area duct geometry is initially defined in order to test the feasibility of the concept; the results from this initial investigation demonstrates possible beneficial effects of depositing energy upstream of a thermally choked duct in terms of causing massive changes in flow patterns, including the reestablishment of supersonic flow throughout the duct. This study ...
Quantification Of Uncertainty In Aerodynamic Heating Of A Reentry Vehicle Due To Uncertain Wall And Freestream Conditions, 2010 Missouri University of Science and Technology
Quantification Of Uncertainty In Aerodynamic Heating Of A Reentry Vehicle Due To Uncertain Wall And Freestream Conditions, Benjamin R. Bettis
"The primary focus of this study is to demonstrate an efficient approach for uncertainty quantification of surface heat flux to the spherical non-ablating heatshield of a generic reentry vehicle due to epistemic and aleatory uncertainties that may exist in various parameters used in the numerical solution of hypersonic, viscous, laminar blunt-body flows with thermo-chemical non-equilibrium. Two main uncertainty sources were treated in the computational fluid dynamics (CFD) simulations: (1) aleatory uncertainty in the freestream velocity and (2) epistemic uncertainty in the recombination efficiency for a partially catalytic wall boundary condition. The Second-Order Probability utilizing a stochastic response surface obtained with ...