Aerospace Engineering Commons^™

Optimization Of Induced-Power From Dynamic Inflow Theory With Realistic Constraints, Chad File

All Theses and Dissertations (ETDs)

Finite-state induced-inflow theory is used to develop an analytic formulation for general performance of the lifting rotor with arbitrary loading. The theory incorporates conventional blade-element theory for blade lift and provides the integrated loads and the induced-power of the rotor in terms of an arbitrary number of rotor controls such as conventional collective and cyclic pitch as well as higher harmonic radial and azimuthal pitch. The theory provides the basis for a classical quadratic optimization with realistic constraints that is applied to determine minimum induced-power for a variety of available control combinations, rotor trim constraints, and operating conditions. The findings …

Design Considerations And Requirements For In-Flight Refueling Of Unmanned Vehicles, Ian R. Mcandrew, Kenneth Witcher

Publications

The need to refuel in-flight has become a significant part of military strategy for air forces to work at further distances from safe shores. The use of Unmanned Vehicles is increasing and expected to be the principal part of military deployment. This paper will address the concepts and requirements for applying refueling unmanned vehicles in a military context for supporting fixed and rotor aircraft. Design aspects of human factors in the process are considered, reviewed and solutions proposed to allow for the first generation of designs to be developed. Furthermore, the practical and operational limitations will be addressed as part …

Orbital Debris Removal Technologies: A Hybrid Electrodynamic Tether And Ion Beam Shepherd Satellite Design For Fuel Efficient Contactless Debris Removal, JöRn Mumme

Doctoral Dissertations and Master's Theses

Space debris poses a serious threat to humanities efforts at space exploration as well as the expanding uses for earth-orbiting satellites. This thesis investigates the proposed technologies for the debris's removal both large and small. Focus is applied to the large debris removal technologies since the small size category is dominated by the ORION laser system. Furthermore, the large debris objects pose the most destructive threat upon impact to satellites. Electrodynamic tethers (EDT) as well as their control strategies, ion-beam shepherds (IBS), and tradition thruster methods are investigated for effectiveness and feasibility. Hybrid combinations of these technologies are investigated in …

Comm-Components Of Link Equation, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs on "Comm-Components of Link Equation" from April 10, 2013.

Broncoblade: An Open Source Wind Turbine Blade Analysis Tool, Alex R. Quinlan

Masters Theses

This thesis reports the development and validation of BroncoBlade, a horizontal axis wind turbine analysis tool. BroncoBlade prepares finite element models and integrates them with an aeroelastic simulator. Analysis results for the SNL100-00 baseline blade are evaluated against reference results published by Sandia National Laboratories. Variations on the SNL100-00 blade incorporating carbon fiber are compared to the baseline blade.

An Experimental Investigation Of The Stol Performance Of Cal Poly's Amelia In The Nfac, Jonathan Andrew Lichtwardt

Master's Theses

Results from Cal Poly's recent wind tunnel test, during the Winter of 2011-2012, in the 40- by 80-foot test section at the National Full-Scale Aerodynamics Complex (NFAC) at NASA Ames Research Center are presented. AMELIA, the Advanced Model for Extreme Lift and Improved Aeroacoustics, is the first full-span, cruise efficient, short take-off and landing (CESTOL) model incorporating leading- and trailing-edge blowing wing circulation control and over-the-wing mounted turbine propulsion simulators (TPS) to date. Testing of the 10 foot span model proved successful and was the result of a 5 year NASA Fundamental Aeronautics Program Research Announcement. The test generated extensive …

Enabling Rapid Conceptual Design Using Geometry-Based Multi-Fidelity Models In Vsp, Joel Brian Belben

Master's Theses

The purpose of this work is to help bridge the gap between aircraft conceptual design and analysis. Much work is needed, but distilling essential characteristics from a design and collecting them in an easily accessible format that is amenable to use by inexpensive analysis tools is a significant contribution to this goal. Toward that end, four types of reduced-fidelity or degenerate geometric representations have been defined and implemented in VSP, a parametric geometry modeler. The four types are degenerate surface, degenerate plate, degenerate stick, and degenerate point, corresponding to three-, two-, one-, and zero- dimensional representations of underlying geometry, respectively. …

Muscle Synergies Improve Estimation Of Knee Contact Forces During Walking, Benjamin J. Fregly, Jonathan P. Walter, Allison Kinney, Scott A. Banks, Darryl D. D'Lima, Thor F. Besier, David G. Lloyd

Mechanical and Aerospace Engineering Faculty Publications

This study investigates whether use of subject-specific muscle synergies can improve optimization predictions of muscle excitation patterns and knee contact forces during walking. Muscle synergies describe how a small number of neural commands generated by the nervous system can be linearly combined to produce the broad range of muscle electromyographic (EMG) signals measured experimentally. By quantifying the interdependence of individual EMG signals, muscle synergies provide dimensionality reduction for the neural control redundancy problem. Our hypothesis was that use of subjectspecific muscle synergies to limit muscle excitation patterns would improve prediction of muscle EMG patterns at the hip, knee, and ankle …

Nasa Magnetospheric Multiscale Mission Tablesat 1c, Joshua Chabot, Joseph Kelley, Michael Johnson

Honors Theses and Capstones

The NASA Magnetospheric MultiScale (MMS) mission (to be launched in 2014) consists of four spin-stabilized spacecraft flying in precise formation. The MMS spacecraft, which have wire booms up to 60 m long, are analyzed using the UNH MMS TableSat IC, a limited 3-DOF rotation (full spin, limited nutation) table top prototype of the MMS spacecraft. A PID controller is implemented on TableSat IC to observe the effects of spin rate and nutation control on the experimental satellite bus and scaled booms. Nutation and spin are implemented independently and the behavior of the test bed with and without SDP booms is …

Development Of Cfd Models For The Purposes Of Exploring Free Surface Wave Phenomena, Leonard P. Stoehr

Masters Theses

With the push for finding alternative, green energy sources, the harnessing of energy from ocean and lake waves is becoming a more researched field. To fully understand the behavior of wave interactions and optimize designs to extract this energy, it is necessary to develop computer models that can accurately replicate this behavior. A case is presented in which previous work done using the wave tank found in the Western Michigan University fluids lab is examined. The case involves harnessing the energy generated by ocean waves through the usage of plates of different shapes resting horizontally on the water’s surface. The …

Application Of Archimedes In Three Dimensions And To Solid Mechanics, Jonathan Aziz

Renée Crown University Honors Thesis Projects - All

ARCHIMEDES is a computerized learning system that has helped Syracuse University students overcome the challenges of Engineering Statics since 2009. Its success has motivated application of ARCHIMEDES to three dimensional problems and to problems in Solid Mechanics. Other learning software was investigated before seven Solid Mechanics problems were written for ARCHIMEDES. A 3D graphical interface was developed and evaluated by a field test of student volunteers. Student preferences for various features in 3D learning software were obtained. It is clear from student responses that having a 3D scene to manipulate improves visualization of the problem, mitigating the ambiguity of a …

Syllabus For Space Systems Engineering 120: Satellites And Space Systems I (Spring 2013), Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

Professor Bob Twiggs' 2013 spring syllabus for Space Systems Engineering 120: Satellites and Space Systems I.

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Pilots For Space Tourism, Robert A. Goehlich, Jay K. Anderson, Nathan N. Harrold, Joseph A. Bemis, Mike T. Nettleingham, Joshua M. Cobin, Bradley R. Zimmerman, Ben L. Avni, Michael D. Gonyea, Nicholas Y. Ilchena

Applied Aerospace Science

This article sheds light on the key player needed for any space tourism adventure: the pilot who flies the spacecraft. The paper addresses the potential benefits of including a pilot at the controls when designing a space tourism spacecraft. It examines the basic qualifications and advanced skills required of space tourism pilots and discusses key training requirements for selected pilots and space pilots’ pay and benefits. In addition, the research concludes that, just as the pioneers of passenger transport in aviation entertained and captured the interest of their passengers, the space pilot should have the skills of a tour guide.

Investigation Of Pulse Detonation Engines; Theory, Design And Analysis, Jeff Vizcaino

Doctoral Dissertations and Master's Theses

Detonation and constant volume combustion has been known to the scientific community for some time but only recently has active research been done into its applications. Detonation based engines have received much attention in the last two decades because of its simple design and potential benefits to the aerospace industry. It is then the goal of this study to provide a background into detonation theory and application and establish the basis for future detonation based research at Embry-Riddle Aeronautical University. In this paper we will discuss the experimental aspects of building, testing, and analysis of a pulsed detonation tube …

A Preliminary Study Of Acoustic Prediction Technology Based On Detached Eddy Simulations For Supersonic Jets Impinging On Flat Plates, Yuvraj Dewan

Doctoral Dissertations and Master's Theses

An application of an existing industry tool to study supersonic jets impinging on at plates is shown. This industry tool is the commercially available CFD package ANSYS FLUENT. The supersonic jet studied is perfectly expanded with a Mach number of 1.5, and it impinges on a flat surface 4 nozzle throat diameters from the jet exit. All turbulence modeling is done using a hybrid RANS/LES technique known as Delayed Detached Eddy Simulation (DDES). A transient solution is calculated using the pressure-based coupled solver formulation with the second-order bounded central-upwind spatial discretization and second-order implicit time marching scheme. Flow features like …

Incorporating Industry Needs Into The Development Of An Undergraduate Degree In Commercial Space Operations, Yash Bipinchandra Mehta

Doctoral Dissertations and Master's Theses

The rapid expansion of the commercial space industry, not unlike the aviation industry in the early 20^th century, has left the industry facing unique challenges. As companies continue to expand, the need for a well-trained workforce becomes critical. The needed workforce must be specifically educated to enter the commercial space industry at graduation. To have a successful industry, a workforce must be trained in skills that meet the industry's needs. In that regard, this study consisted of a survey of leaders in the commercial space industry to identify the different skill-sets sought by the industry. The results of the …

An Investigation To Advance The Technology Readiness Level Of The Centaur Derived On-Orbit Propellant Storage And Transfer System, Nathan L. Silvernail

Doctoral Dissertations and Master's Theses

This research was carried out in collaboration with the United Launch Alliance (ULA), to advance an innovative Centaur-based on-orbit propellant storage and transfer system that takes advantage of rotational settling to simplify Fluid Management (FM), specifically enabling settled fluid transfer between two tanks and settled pressure control. This research consists of two specific objectives: (1) technique and process validation and (2) computational model development. In order to raise the Technology Readiness Level (TRL) of this technology, the corresponding FM techniques and processes must be validated in a series of experimental tests, including: laboratory/ground testing, microgravity flight testing, suborbital flight testing, …

Measuring Acoustic Attenuation Of Polymer Materials Using Drop Ball Test, Yi Zhang

Doctoral Dissertations and Master's Theses

Polymers are often used for vibration damping and energy absorption. The effect of a material in reducing the strength of sound waves traveling through it is called acoustic attenuation. In the past, attenuation has mostly been evaluated in the MHz frequency range, using a pulse generator and transmitting transducer as the wave source. However, most real acoustic activities occur at frequencies up to a few hundred kHz. Here, a simple drop ball mechanism is used to generate acoustic source waves in the kHz range, and the attenuation capacities of several solid materials are measured. The recorded waveforms substantially differ between …

Nonlinearity Index Analysis Of Periodic-Chaotic Stall-Spin Aircraft Motion, Daniel Paul Tapolcai

Mechanical & Aerospace Engineering Theses & Dissertations

This thesis explores the application of nonlinearity index theory to the nature of stalling and spinning aircraft motions. Nonlinear dynamic phenomena related to stall and spin have been a concern to flight engineers and pilots for generations. Considerable past work has been directed to detect and understand the cause and nature of these phenomena. Methods such as bifurcation analysis, Volterra expansion series, and nonlinear simulation are a few of the nonlinear approaches developed to study this topic. Traditionally, however, linear analysis is the most widely used approach for studying aircraft dynamical behavior under a given set of acceptable conditions. This …

Investigation Of Buoyant Transport Systems For Martian Exploration, Jake A. Tynis

Mechanical & Aerospace Engineering Theses & Dissertations

This thesis has investigated the feasibility of utilizing hydrogen-filled balloons as transport systems to accelerate robotic exploration of Mars. Assuming that a fixed robotic base is established at a Mars surface location that is accessible to water ice, electrolysis of in situ water to produce hydrogen is straight forward. A recent Master's thesis determined that global wind patterns at Mars were strong at most times of the year and predictable. On that basis, it was possible to investigate the feasibility of employing surface-launched, hydrogen-filled balloons to transport 100 kg payloads over great distances and to otherwise inaccessible locations throughout Mars. …