Aerospace Engineering Commons^™

Capillary-Driven Flows Along Rounded Interior Corners, Yongkang Chen, Mark M. Weislogel, Cory L. Nardin

Mechanical and Materials Engineering Faculty Publications and Presentations

The problem of low-gravity isothermal capillary flow along interior corners that are rounded is revisited analytically in this work. By careful selection of geometric length scales and through the introduction of a new geometric scaling parameter Tc, the Navier–Stokes equation is reduced to a convenient∼O(1) form for both analytic and numeric solutions for all values of corner half-angle α and corner roundedness ratio λ for perfectly wetting fluids. The scaling and analysis of the problem captures much of the intricate geometric dependence of the viscous resistance and significantly reduces the reliance on numerical data compared with several previous solution methods …

Integrated Guidance And Control Of Missiles With Θ-D Method, Ming Xin, S. N. Balakrishnan, Ernest J. Ohlmeyer

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A new suboptimal control method is proposed in this study to effectively design an integrated guidance and control system for missiles. Optimal formulations allow designers to bring together concerns about guidance law performance and autopilot responses under one unified framework. They lead to a natural integration of these different functions. by modifying the appropriate cost functions, different responses, control saturations (autopilot related), miss distance (guidance related), etc., which are of primary concern to a missile system designer, can be easily studied. A new suboptimal control method, called the θ-D method, is employed to obtain an approximate closed-form solution to this …

Rideshare Conference, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "RideShare Conference" from October 11, 2006.

A New Approach To Satellite Power Systems, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "A New Approach To Satellite Power Systems" from October 8, 2006.

Suitsat-2, Lou Mcfadin, Frank Bauer

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Lou McFadin and Frank Bauer titled "SuitSat-2" from October 8, 2006.

Stanford University’S Small Satellite Program: Amsat Space Symposium, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Stanford University’s Small Satellite Program: AMSAT Space Symposium" from October 7, 2006.

Optimization Of Active Rendezvous Trajectories By Genetic Algorithms, Marie Emmanuelle Ricour

Master's Theses - Daytona Beach

Trajectory optimization is and will remain a hot topic in the engineering field. Because analytical or exact solutions are often difficult and sometimes impossible to compute, there is a need for alternative and efficient methods. UnderWater Vehicles (UWV) trajectories and rendezvous trajectories of continuous low-thrust spacecraft are examined. One of the methods to solve such problems is the Genetic Algorithm (GA) method. In this work, a GA has been developed using Matlab®. It treats possible solutions to the studied problems as individuals and eventually converges to an optimal or near optimal solution. Genetic Algorithms have been used previously to solve …

Evaluation Of Probabilistic Methodology For Predicting Satellite Tracking Resources, Matthew Lynn Stubbe

Master's Theses - Daytona Beach

This research evaluates a probabilistic methodology for estimating the ability of satellite tracking networks to provide tracking and data acquisition services to large constellations of satellites. This approach, developed by Hagar is evaluated using Monte Carlo simulations of optimal satellite contact scheduling on a tracking network for a certain class of satellites. The actual results of the scheduled Monte Carlo simulations were then compared to the predicted values computed with Hagar's methodology for a range constellation and network sizes. Comparison methods include percent difference, a Wilcoxon signed ranks test and a Mann-Whitney U test.

The Monte Carlo simulations were run …

Flow Control Of Airfoil At Post-Stall Conditions By Multiple Frequency Applied Saado Jets, A. Şamil Demirsöz

Mechanical & Aerospace Engineering Theses & Dissertations

Flow separation over lifting aerodynamic components, such as airfoils and wings, occurs during stall conditions which are caused by adverse changes (i.e.; high angle of attack, inflow conditions, etc.) in the operating conditions of aerodynamic components. During stall conditions, the flow over airfoil loses its momentum, creating high pressure zones on the upper surface of the airfoil and even a small increase in pressure causes the fluid particles to stop and separate to a low pressure zone. In order to eliminate the flow separation, the low momentum flow should be removed in order to maintain the high momentum and low …

Come-Back Competition: 2006 Summary, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by Professor Bob Twiggs titled "Come-Back Competition: 2006 Summary" from September 23, 2006.

Arliss 2006 Cansat: Da Vinci, Matsunaga Lab, Tokyo Institute Of Technology

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by the Matsunaga Lab of Tokyo Institute of Technology titled "ARLISS 2006 CanSat: Da Vinci" from September 23, 2006.

Arliss 2006 Report, Tohoku University Sekiguteam

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by the Tohoku University Sekiguteam  titled "ARLISS 2006 Report" from September 23, 2006.

Arliss 2006: University Of Tokyo & Seoul National University, Team Snut

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created Team SNUT titled "ARLISS 2006: University of Tokyo & Seoul National University" from September 23, 2006.

Samurai, University Of Tokyo Rover Team

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by the University of Tokyo Rover Team titled "Samurai" from September 23, 2006.

Cbc-03: Nihon University, Yuta Chiba, Yuta Kujira

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by Yuta Chiba and Yuta Kujira titled "CBC-03: Nihon University" from September 23, 2006.

Airsat Project: Design And Construction Of An Autonomous Atmospheric Probe, Jornados De Jovenes Cientificos

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by the Jornadas de Jóvenes Científicos titled "AIRSat Project: Design and construction of an autonomous atmospheric probe" from September 23, 2006.

T. I. Tech Arliss Team: Spopovic, Tokyo Insititute Of Technology Arliss Team

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by the Tokyo Insititute of Technology ARLISS Team titled "T. I. Tech ARLISS Team: Spopovic" from September 23, 2006.

Arliss 2006: Comeback Competition Report, Tohoku University Yashago Team

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by the Tohoku University Yashago Team titled "ARLISS 2006: Comeback Competition Report" from September 22, 2006.

Result Of Arliss "Coolrunning Ver. 3", Osamu Kitagawara, Yusuke Saisoh

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by Osamu Kitagawara and Yusuke Saison titled "Result of ARLISS CoolRunning Ver. 3" from September 22, 2006.

Aoyama Gakuin University: I Can Fly, Kuninori Togai, Satoshi Adachi, Naoki Kitabayashi

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by the Aoyama Gakuin University Space Club on September 22, 2006.

Mavericks & 2007 International Civilian Space Competition, Thomas M. Atchison

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Thomas M. Atchison titled "Mavericks & 2007 International Civilian Space Competition" from September 22, 2006.

Error Allocation In Complex Systems Design, Robert A. Mcdonald

Aerospace Engineering

A fidelity trade environment was conceived, formulated, developed, and demonstrated. This development relied on the advancement of enabling techniques including error propagation, metamodeling, and information management. These techniques were integrated with an existing commercial systems design framework and an intuitive graphical interface to create a fidelity trade environment. A sensitivity approach to the propagation of error through complex systems was developed. This approach relied on the system sensitivity matrix to model the behavior of a complex system as a whole. In verification tests, the sensitivity approach provided approximate results substantially similar to a Monte Carlo approach that was many orders …

Lightweight In-Plane Actuated Deformable Mirrors For Space Telescopes, Michael J. Shepherd

Theses and Dissertations

This research focused on lightweight, in-plane actuated, deformable mirrors, with the ultimate goal of developing a 20- meter light gathering aperture for space telescopes. The 0.127 meter diameter deformable mirror small scale testbed was modelled infinite elements using MSC.Nastran software and then used as a basis for a quasi-static controller. Experimental tracking of Zernike tip, tilt, and defocus modes was accomplished. The analytical solutions to plate-membrane and beam-string ordinary differential equations were developed. A simplified approach to modelling the axisymmetric cases was also presented. A novel static control strategy, the Modal Transformation Method, was developed to form Zernike surfaces within …

Dynamics And Control Of Tethered Satellite Formations For The Purpose Of Space-Based Remote Sensing, Kurt A. Vogel

Theses and Dissertations

This dissertation assesses the utility of tethered satellite formations for the space-based remote sensing mission. Energy dissipation is found to have an adverse effect on foundational rigid body (Likins-Pringle) equilibria. It is shown that a continuously earth-facing equilibrium condition for a fixed-length tethered system does not exist since the spin rate required for the proper precession would not be high enough to maintain tether tension. The range of required spin rates for steady-spin motion is numerically defined here, but none of these conditions can meet the continuously earth-facing criteria. Of particular note is the discovery that applying certain rigid body …

Scaling Flight Tests Of Unmanned Air Vehicles, Jeevani I. Abeygoonewardene

Theses and Dissertations

Increasing technological advances and research interest in unmanned air vehicles (UAVs), have led to the need for having safe, inexpensive and effective means of experimenting with their fight performance and surveillance capabilities. Work has previously been done in areas of controlling, analyzing, and predicting cooperative and autonomous operations of UAVs and other vehicles. In addition, there are well established guidelines for scaling experiments in fluid mechanics, where geometric, kinematic and dynamic similarity is obtained by formulating problems in terms of non dimensional variables using dimensional analysis. However, little or no work has been done in developing experiments or guidelines for …

Development Of A Low-Latency, High Data Rate, Differential Gps Relative Positioning System For Uav Formation Flight Control, Stephen J. Comstock

Theses and Dissertations

In order for Unmanned Aerial Vehicles (UAVs) to be able to fly missions currently performed by manned aircraft, they must be able to conduct in-flight refueling. Additionally, significant fuel savings can be realized if multiple UAV's are able to fly in precise formation and align wingtip vortices. In either case, the precise relative position between the aircraft must be known to an accuracy of only a few centimeters. Previous research at the Air Force Institute of Technology culminated in the development of a relative positioning system for manned aircraft. This thesis presents the development of the next-generation system designed for …

Dual Fine Tracking Control Of A Satellite Laser Communication Uplink, Louis A. Noble

Theses and Dissertations

A dual fine tracking control system (FTCS) is developed for a single aperture optical communication receiver to compensate for high frequency disturbances affecting tracking of two incident laser communication beams. The optical communication receiver resides within a payload module aboard a geosynchronous satellite, while each laser communication transmitter is housed within a module aboard a high altitude unmanned aerial vehicle (UAV). In addition to platform specific disturbances, the impact of atmospheric optical disturbances affecting tracking error are investigated. The system dynamics and FTCS are modeled and evaluated in MATLAB and SIMULINK. An optimal controller is developed to mitigate these disturbances …

Development And Testing Of A High-Speed Real-Time Kinematic Precise Dgps Positioning System Between Two Aircraft, Christopher J. Spinelli

Theses and Dissertations

This research involves the design, implementation, and testing of a high-speed, real-time kinematic, precise differential GPS positioning system for use in airborne applications such as automated aerial-refueling and close formation flying. Although many of the current ambiguity resolution techniques use the residuals from the least squares position estimation to determine the true ambiguity set, this thesis presents a novel approach to the ambiguity resolution problem, called the minimum indicator. Instead of assuming the ambiguity set with the lowest residuals is the true set, other special characteristics of the residuals are examined. This increases the confidence that the algorithm has selected …

Structural Analysis Of The Rigidizable Inflatable Get-Away-Special Experiment, Anna E. Gunn-Golkin

Theses and Dissertations

The purpose of this research was to validate the structural integrity of the Rigidizable Inflatable Get-Away-Special Experiment (RIGEX) and make appropriate improvements to the design, motivated by static and dynamic analysis results. RIGEX is designed to advance the use of rigidizable inflatable structures in the space environment by providing three sets of on-orbit test data on the structural characteristics of three thermoplastic composite tubes. This thesis discusses the RIGEX structural analysis. The term structural analysis refers to the development of a detailed finite element model and the tests for which the model was used. The finite element model provided an …

Modeling Fracture In Z-Pinned Composite Co-Cured Laminates Using Smeared Properties And Cohesive Elements In Dyna3d, Jason K. Freels

Theses and Dissertations

The purpose of the present research was three-fold: 1) gain a more sophisticated understanding of the response of co-cured composite joints with and without through-thickness reinforcement (TTR), 2) compare the behavior of specimens reinforced with various sizes and densities of reinforcement, and 3) use experimental data to verify the existing DYNA3D smeared property model. Double cantilever beam, end-notch flexure and T-section specimens reinforced with 0.011" diameter z-pins at 2% and 4% volume densities were tested to determine the mode I, mode II and mixed mode (I and II) behavior. Results were added to preliminary research in which tests were conducted …