Aerospace Engineering Commons^™

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.

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 …

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 …

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 …

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.

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.

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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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 …

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. …

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 …

Characterization Of A Spiral Microfluidic Focusing Device For Continuous Single Cell Impedance-Based Cytometry Applications, Daniel Riley

Mechanical & Aerospace Engineering Theses & Dissertations

A major focus in the field of cell characterization is the quantification of cell dielectric properties in order to develop low-cost, portable microfluidic devices that can, among other things, perform point-of-care detection of rare diseases and complete blood counts. Impedance-based cytometry has become an advantageous tool to ascertain these properties, wherein it is important that cells pass through the same point in a channel cross-section one at a time to ensure accurate and repeatable readings. This study documents the assessment of an 8-loop 160 μm (W) x 80 μm (H) spiral microchannel used to focus 10 μm polystyrene particles. In …

Micro--Piv Measurements And Numerical Simulations Of Induced Charge Electro-Osmosis Around A Conducting Metal Rod, William George Rosen

Mechanical & Aerospace Engineering Theses & Dissertations

The induced charge electro-osmotic (ICEO) flow around a conducting metal rod positioned in the center of a microchannel was analyzed through physical experimentation and numerical simulation. The experimental set up consisted of a straight microchannel connecting two fluid reservoirs with a square wave AC electric field applied across the microchannel. The electric field for the experimental tests ranged from 100 V /cm to 200 V/cm at frequencies from 500 Hz to 1.5 kHz. The numerical simulations used a similar geometric setup but were exposed to both a direct current (DC) and alternating current (AC) applied electric field. The electric field …

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. …

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 …

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 …

Communications: Moving Data, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs on "Communications: Moving Data" from March 24, 2013.

Evaluation Of The Thorax Of Manduca Sexta For Flapping Wing Micro Air Vehicle Applications, Brian C. Cranston

Theses and Dissertations

The tobacco hornworm hawkmoth (Manduca sexta) provides an excellent model from which to gather knowledge pertaining to the development of a Flapping Wing Micro Air Vehicle (FWMAV). One of the major challenges in design of a FWMAV is the energy demanding nature of low Reynolds number flapping flight. Therefore, an understanding of the power required by the flight muscles to actuate the wings is essential for the design of a FWMAV. The M.sexta wing/thorax mechanism was evaluated as a mechanical system in order to gain insight to the mechanical power required to produce the full natural wing stroke. A unique …

Power Requirements For Bi-Harmonic Amplitude And Bias Modulation Control Of A Flapping Wing Micro Air Vehicle, Justin R. Carl

Theses and Dissertations

Flapping wing micro air vehicles (FWMAV) have been a growing field in the research of micro air vehicles, but little emphasis has been placed on control theory. Research is ongoing on how to power FWMAVs where mass is a major area of concern. However, there is little research on the power requirements for the controllers to manipulate the wings of a FWMAV. A novel control theory, BABM, allows two actuators to produce forces and moments in five of the FWMAV's six DOF. Several FWMAV prototypes were constructed and tested on a six-component balance. Data was collected for varying control parameters …

Opto-Mechanical Design Of A Chromotomographic Imager Direct-Vision Prism Element, Timothy E. Coon

Theses and Dissertations

Chromotomographic Imaging (CTI) offers advantages in remote sensing by resolving intensity distribution spatially, spectrally, and temporally. The Chromotomography Experiment (CTEx) at the Air Force Institute of Technology (AFIT) explores the application of CTI as a space-based observer. Previous work in instrument development has revealed many of the intricacies of component fabrication and how they impact the resolving of image data. The proposed CTEx instrument has as its chromatic dispersion element a direct-vision prism (DVP) that is made to rotate in order to achieve multiple projection angles. Analysis of previous research established the need for a more accurate characterization of the …

Characterization Of Rotating Detonation Engine Exhaust Through Nozzle Guide Vanes, Nick D. Debarmore

Theses and Dissertations

A RDE has higher thermal efficiencies in comparison to its traditional gas turbine counterparts. Thus, as budgets decrease and fuel costs increase, RDEs have become a research focus for the United States Air Force. An integration assembly for attaching the first NGV section from a T63 gas turbine engine to a 6 inch diameter RDE was designed and built for this study. Pressure, temperature, and unsteadiness measurements were completed in this study to characterize the exhaust flow of the RDE through the NGVs. The experiment found that stagnation pressure dropped an average of 4% through the NGVs, and that unsteadiness …

Computational Simulation Of Explosively Generated Pulsed Power Devices, Mollie C. Drumm

Theses and Dissertations

Technology and size constraints have limited the development of the end game mechanisms of today's modern military weapons. A smaller, more efficient means of powering these devices is needed, and explosive pulsed power devices could be that answer. While most prior research has been in the experimental field, there is a need for more theory-based research and a computer modeling capability. The objective of this research was to use experimental data collected by the US Army at Redstone Arsenal from their ferroelectric generator (FEG) design in combination with the ALEGRA-EMMA code to develop a computer model that can accurately represent …

Feasibility Analysis On The Utilization Of The Iridium Satellite Communications Network For Resident Space Objects In Low Earth Orbit, John R. Claybrook

Theses and Dissertations

In recent years, space has become more congested and contested, particularly in low Earth orbit (LEO), generating the need for a low-latency capability to provide precise orbital knowledge and accurate space situational awareness information. This thesis investigates the feasibility of resident space objects (RSOs) in LEO communicating continuously with ground operators or users through the Iridium Satellite Communications Network. Due to the problem's complexity and required time for computation, a test-industry technique called Design of Experiments is implemented in order to efficiently study the feasibility of the communication link. Specifically, an optimal response surface method is chosen to design the …

Using Hysteretic Energy To Evaluate Damping Characteristics Of Hard Coating On Titanium, Colin C. Engebretsen

Theses and Dissertations

Current methods of material damping evaluation consist of bending tests involving half-power bandwidth base excitation or free decay methods measured by laser vibrometer. These methods are accompanied by complex, nonlinear strain evaluation; they are vulnerable to undesired air damping; and they require less than commonplace equipment. The measurement of hysteretic energy loss in axial cyclic loading alleviates these difficulties. By using common tensile testing machines, strain is kept linear and air damping is of no concern. Furthermore, the static test section allows for simplified environmental variation for high temperature or high humidity testing. This study set forth to advance and …

Application Of Finite Element To Evaluate Material With Small Modulus Of Elasticity, Boyce H. Dauby

Theses and Dissertations

This thesis describes the development of a series of models utilizing the commercial finite element suite ABAQUS specifically to apply towards the study of biological tissue. The end goal is to be able to obtain the material properties of the Manducca Sexta, a biological inspiration for flapping wing micro-air vehicles. Two finite element models were used to analyze the results of two prior studies of other researchers. A flat punch elastic model examined boundary effects and confirmed that the point of indentation was far enough removed from the boundary. The hyperelastic spherical indentation experiment examined the effects of coefficient of …