Aerospace Engineering Commons^™

Effect Of Sustainable And Composite Materials On The Mechanical Behavior Of Sandwich Panels Under Edgewise Compressive Loading, Justin A. Tafoya

Master's Theses

Over the last three decades, the aerospace industry has gradually shifted from metals to composites in many different applications due to the lightweight properties of composite materials. Some benefits of composites include higher strength-to-weight ratio and corrosion resistance. At this point in time, the composite industry researchers are focusing on renewable and sustainable materials (bio-composites). By understanding the structural capabilities of bio-composites that have been used for centuries, new developments of sustainable materials will spark more interest throughout the industry. Bio-composites include fibers such as hemp, bamboo, flax, etc. The high demand for bio-composites in composite structures can also reduce …

Aircraft De-Icing System Using Thermal Conductive Fibers, Min Soon Park

Doctoral Dissertations and Master's Theses

The accumulation of ice on the leading edges of aircraft wing poses complications for flight control as drag is increased with a tendency for higher relative turbulence over the wing. Pre-emptive and reactive ice removal techniques have been employed in the past by electromechanical, thermal, chemical and pneumatic methods. In this thesis, a carbon fiber fabric is utilized as a heating de-icer for composites aircraft wing surface structures. Two prototypes are constructed, tested to generate temperature profiles, and an appropriate heating voltage is selected for effective de-icing via distinct avenues of heating system configurations. The heat transfer efficiency of the …

A Contribution Toward Better Understanding Of Overbanking Tendency In Fixed-Wing Aircraft, Nihad E. Daidzic

Journal of Aviation Technology and Engineering

The phenomenon of overbanking tendency for a rigid-body, fixed-wing aircraft is investigated. Overbanking tendency is defined as a spontaneous, unbalanced rolling moment that keeps increasing an airplane’s bank angle in steep turns and must be arrested by opposite aileron action. As stated by the Federal Aviation Administration, the overbanking tendency may lead to a loss of control, especially in instrument meteorological conditions. It was found in this study that the speed differential over wing halves in horizontal turns indeed creates a rolling moment that achieves maximum values for bank angles between 45 and 55 degrees. However, this induced rolling moment …

The Influence Of Cornering On The Vortical Wake Structures Of An Inverted Wing, James Keogh, Graham Doig, Sammy Diasinos, Tracie Barber

Aerospace Engineering

The aerodynamic performance of inverted wings on racing-car configurations is most critical when cornering; however, current wind tunnel techniques are generally limited to the straight-line condition. The true cornering condition introduces complexity because of the curvature of the freestream flow. This results in an increase in the tangential velocity with increasing distance from the instantaneous centre of rotation and causes the front wing to be placed at a yaw angle. Numerical simulations were used to consider an 80% scale front wing when steady-state cornering with radii ranging from 60m to 7.5 m, and yaw angles ranging from 1.25° to 10°. …

Computational Fluid Dynamics Simulation Of Intracranial Aneurysms - Comparing Size And Shape, Zifeng Yang, Hongtao Yu, George P. Huang, Ryan Schwieterman, Bryan Ludwig

Mechanical and Materials Engineering Faculty Publications

Objective: To study the hemodynamics of an anatomic internal carotid artery aneurysm derived from a patient-specific model and then manipulate into two phantom morphologies: one growing uniformly by size and the other changing shape unevenly. Methods: The computational model of the saccular, internal carotid artery, aneurysm was constructed from 3D rotational, digitally subtracted, catheter angiography images. Computational fluid dynamics simulations were performed under pulsatile cardiac flow conditions. Velocity vectors, streamlines, pressure, and wall shear stress (WSS) and its variance distributions were quantitatively visualized. Results: The maximum pressure and WSS from the time-averaged distribution on the inside saccular surface of the …

Waste And Duplication In Nasa Programs: The Need To Enhance U.S. Space Program Efficiency, Bert Chapman

Libraries Faculty and Staff Scholarship and Research

The U.S. Government faces acute budgetary deficits and national debt problems in the Obama Administration. These problems have been brought about by decades of unsustainable government spending affecting all agencies including the National Aeronautics and Space Administration. (NASA). An outgrowth of this fiscal profligacy is the presence of wasteful and duplicative programs within NASA that prevent this agency from achieving its space science and human spaceflight objectives. These problems occur due to mismanagement of these programs from NASA and the creation of these programs by the U.S. Congress and congressional committees. This occurs because congressional appropriators tend to be more …

Does Material Choice Drive Sustainability Of 3d Printing?, Jeremy Faludi, Zhongyin Hu, Shahd Alrashed, Christopher Braunholz, Suneesh Kaul, Leulekal Kassaye

Dartmouth Scholarship

Environmental impacts of six 3D printers using various materials were compared to determine if material choice drove sustainability, or if other factors such as machine type, machine size, or machine utilization dominate. Cradle-to-grave life-cycle assessments were performed, comparing a commercial-scale FDM machine printing in ABS plastic, a desktop FDM machine printing in ABS, a desktop FDM machine printing in PET and PLA plastics, a polyjet machine printing in its proprietary polymer, an SLA machine printing in its polymer, and an inkjet machine hacked to print in salt and dextrose. All scenarios were scored using ReCiPe Endpoint H methodology to combine …

Economic Interrelationships And Impacts Of The Aviation/Aerospace Industry In The State Of Florida Using Input-Output Analysis, Kelly A. Whealan-George

Doctoral Dissertations and Master's Theses

The study provided a detailed description of the interrelatedness of the aviation and aerospace industry with principal industries in Florida and Volusia County (VC) using Input-Output (IO) analysis. Additionally, this research provided an economic impact analysis of the creation of a university research park in Daytona Beach (DB). The economic impact measures included not only direct economic output and industry employment descriptions but also described the multiplier effects in the form of indirect and induced impacts using data for 2012.

This research concluded the average labor income of the aviation and aerospace industry was higher than average labor income in …

Energy Use & Generation, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs on "Energy Use & Generation" from January 19, 2015.

Autonomous Satellite Recovery Vehicle, William Lewis, Devonte Grantham, Francisco Pastrana, Shane Williams, Joshua Moffett, Jessy Law, Kyle Ouellette, Janet Marnane

Aviation / Aeronautics / Aerospace International Research Conference

In collaboration with ERFSEDS, we would like to send a small satellite attached to a quad-copter as the payload for ERFSEDS rocket which will reach an altitude of 10,000 feet. The quad-copters objective will be to collect atmospheric data as it descends. Our plan is to 3-D print a new chassis for the quad-copters electronic components and arms that will allow the quad-copter to fold its arms inwards to meet the required space constraints. After launching the rocket, the satellite will be deployed at the target altitude and begin collecting data once jettisoned from the rocket. Once reaching 2,000 feet …

Atmospheric Weather Balloon For Near Space Research, Francisco F. Pastrana, Devonte Grantham, Shane M. Williams, Jessy Law, Jennifer Nason, Janet Marrnane

Aviation / Aeronautics / Aerospace International Research Conference

Atmospheric Weather Balloon for Near Space Research

The Society for S.P.A.C.E. has been working on the development of a weather balloon that will reach a height of 80 to 100 thousand feet and will collect data from the atmosphere. The weather balloon is attached to a Styrofoam box that contains an Arduino board controlling a set of sensors that will measure: temperature, humidity, atmospheric pressure, wind speed and direction.

The data will be collected and transmitted through an Xbee antenna that will provide us with remote monitoring capabilities. The data and images gathered will aid understanding of the characteristics and …

Suborbital Spaceflight: A Student Team’S Plan To Send A Rocket To Space, Bryce Chanes, William Carpenter, Julio Benavides, Matthew Haslam, Brenda Haven

Aviation / Aeronautics / Aerospace International Research Conference

The Eagle Space Flight Team was created with the goal of becoming the first undergraduate team to design, build, and launch a rocket capable of suborbital spaceflight. In order to achieve this goal, the team will have to design a rocket capable of atmospheric flight at speeds over Mach 5 and launch it on one of the largest amateur rocket motors ever made. Over the next three years, the team will progress towards accomplishing this feat through a series of incremental test flights. Before the space flight, the team will build three sub-scale rockets designed to reach altitudes of 30,000’, …

Low Fidelity Flight Simulation In Collegiate Aviation, Vladimir N. Risukhin

Aviation / Aeronautics / Aerospace International Research Conference

Aviation college pilot training programs, lessons and exercises contain portions that do not require training in sophisticated and highly expensive full flight simulators and flight training devices (FTD) with high fidelity of simulation, or in real aircraft flights. Relatively inexpensive personal-computer-based flight simulation facilities named low fidelity simulators (LFS) can boost development of aircraft pilots’ cognitive and behavioral skills. The paper attempts to reveal how the LFS can support aviation college flight training and research activities. In the Western Michigan University College of Aviation, peer mentoring technique proven to be helpful in higher education institutions has been applied to flight …

Microcontrollers In The Aviation Classroom, Padraig Houlahan

Aviation / Aeronautics / Aerospace International Research Conference

Modern commercial aircraft are increasingly dependent on digital technologies that detect sensor data and pilot control movements, interpret them, and then issue appropriate control signals to remote motors that move control surfaces. Because such technologies are innately complex, it would appear there is an unacceptably large academic burden on introducing them into the undergraduate pilot's curriculum .

However, in recent years there has been an explosion of interest in using micro-controllers in academic teaching (high-school and undergraduate levels) and in hobby applications, resulting in a large, online, freely available knowledgebase of techniques and solutions. Here, I demonstrate how easy it …

Unlocking The Mysteries Of Flight: From The Top Down, Juan Merkt

Aviation / Aeronautics / Aerospace International Research Conference

Traditionally, principles of flight are taught from the bottom-up. That is, we start by examining underlying causes (properties of air) and later move up to top consequences (aircraft performance). This traditional approach is analogous to that used by airplane designers and is most obvious in theory of flight textbooks for pilots. The problem with a bottom-up approach is that it introduces basic concepts as isolated “parts” without providing a “big picture” context. This can lead to poor understanding among student pilots. I suggest an opposite approach. Rather than starting with the underlying causes of flight, we can unravel basic principles …

Thinking Rather Than Panicking About The Current Drone Threat, Tom Foley, Tyrone Groh

Aviation / Aeronautics / Aerospace International Research Conference

Originally titled "UAS Threats in Sport Venues," the authors opted to expand their focus to better to all threats from UASs, and to encourage better preparation for and responses to such threats. Foley and Groh discuss different strategies.

Developing A Robust Balance For Wingsuit Aerodynamic Research, Timothy A. Sestak

Aviation / Aeronautics / Aerospace International Research Conference

Research on wingsuit aerodynamics requires specialized wind tunnel equipment. There is the potential for the relatively large ram-air inflated fabric airfoils being examined to flap and oscillate uncontrolled in the wind tunnel airflow. This chaotic combination of motion and forces could damage the fragile precision balances currently used. Due to the relatively recent development of wingsuit flight as an active sport, there is very little background literature on wingsuit aerodynamics, wingsuit testing, and the equipment and sensors required. A new balance design, able to accurately measure and record basic lift and drag forces while also being able to withstand the …

Insights Into Uas Accidents And Incidents, Robert Joslin

Aviation / Aeronautics / Aerospace International Research Conference

The proliferation and extension of unmanned aircraft systems from military to civil and public use applications has rapidly outpaced the safety analysis that is normally associated with the introduction of a new and novel aircraft. Insights into the types of anomalous events associated with accidents and incidents involving civil and public use unmanned aircraft systems operating in the National Airspace System were derived from an information synthesis of archival publically available reports from the FAA Preliminary Reports of Unmanned Aircraft System Accidents and Incidents database, as recorded in the Aviation Safety Information and Analysis Sharing system. The vast majority of …

Human Factors Considerations In Autonomous Lethal Unmanned Aerial Systems, Kristine Kiernan

Aviation / Aeronautics / Aerospace International Research Conference

The United States military is committed to the development of complete autonomy in unmanned vehicles, including armed unmanned aerial systems (UAS). The design and deployment of autonomous lethal UAS raises ethical issues that have implications for human factors. System design, procedures, and training will be impacted by the advent of autonomous lethal UAS. This paper will define relevant vocabulary, review the literature on robot ethics as it applies to the military setting, discuss various perspectives in the research community, address levels of UAS autonomy, and discuss implications for operator training, responsibility, and human-machine interaction. Familiarity with these ethical issues and …

Time-Resolved Argon Theta-Pinch Plasma Properties By Line Ratio Method With Collisional-Radiative Model, Warner C. Meeks, Joshua L. Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Effect Of A Dc Preionization Source On Energy Deposition In A Pulsed Inductive Plasma, Ryan A. Pahl, Joshua L. Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

A Low-Cost, Software Defined, Ground-Based Radio Frequency Beacon Receiver (Rfbr) For Measuring Ionosphere Tec And Amplitude And Phase Scintillation, Jacob Gunther, Chad Fish, Charles Swenson, Tim Neilsen, Brent Haslem, Bryan Hansen, Kelby Davis, Steve Higley, Todd Parris, Don Thompson, Charles Rino, Keith Groves

Space Dynamics Laboratory Publications

By monitoring the effects of the ionosphere on multiple space originating radio frequency (RF) beacons, characterizing parameters can be derived which can then be ingested into global assimilative models to improve ionospheric specification and to estimate ionosphere-induced degradation of communication and navigation signals across the electromagnetic spectrum. This paper describes the requirements, design and construction of a ground-based beacon receiver for measuring total electron concentration and amplitude and phase scintillation of the ionosphere. The design achieves very low cost by using the latest in commercial RF and software defined radio technology. The receiver can simultaneously observe three tones spanning ultra-high …

Aerodynamic Testing And Development Of Sunswift Eve, Simon Ambrose, Graham Doig

Aerospace Engineering

The current understanding of the aerodynamic performance of Sunswift’s solar-electric race car eVe is limited, despite the design and manufacture of the vehicle in 2012-13. This paper describes an investigation into the aerodynamic behaviour of the vehicle and details the successive design and development of drag minimisation strategies. A study of the ex­ternal airflow around the vehicle was undertaken through a computational fluid dynamics analysis, with validation offered through the results of real-world track testing. Particular reference is made to the Sunswift team’s successful long-range electric vehicle land speed record attempt on 23 July 2014. A predicted 10% reduction in …

Numerical Investigation On Charring Ablator Geometric Effects: Study Of Stardust Sample Return Capsule Heat Shield, Haoyue Weng, Alexandre Martin

Mechanical Engineering Faculty Publications

Sample geometry is very influential in small charring ablative articles where 1D assumption might not be accurate. In heat shield design, 1D is often assumed since the nose radius is much larger than the thickness of charring. Whether the 1D assumption is valid for the heat shield is unknown. Therefore, the geometric effects of Stardust sample return capsule heat shield are numerically studied using a material response program. The developed computer program models material charring, conductive heat transfer, surface energy balance, pyrolysis gas transport and orthotropic material properties in 3D Cartesian coordinates. Simulation results show that the centerline temperatures predicted …

A Multi-Scale Based Model For Composite Materials With Embedded Pzt Filaments For Energy Harvesting, A.E. El-Etriby, M.E. Abdel-Meguid, K.M. Shalan, Tarek Hatem, Yehia Bahei-El-Din

Centre for Advanced Materials

Ambient vibrations are major source of wasted energy, exploiting properly such vibration can be converted to valuable energy and harvested to power up devices, i.e. electronic devices. Accordingly, energy harvesting using smart structures with active piezoelectric ceramics has gained wide interest over the past few years as a method for converting such wasted energy. This paper provides numerical and experimental analysis of piezoelectric fiber based composites for energy harvesting applications proposing a multi-scale modeling approach coupled with experimental verification. The multi-scale approach suggested predicting the behavior of piezoelectric fiber-based composites use micromechanical model based on Transformation Field Analysis (TFA) to …

Intelligent Control Of Miniature Holonomic Vertical Take-Off And Landing Robot, Mohammad A. Jaradata, Mohamed Al-Fandia, Omar Alkhatiba, Yousef Sardahi

All Engineering Faculty Research

This paper discusses the development of a fuzzy based controller for miniaturized unmanned aerial vehicle (UAV).This controller is designed to control the center-of-gravity (CoG) in a new configuration of coaxial miniaturized flying robot (MFR). The idea is to shift the CoG by controlling two pendulums located in perpendicular directions; each pendulum ends with a small mass. A key feature of this work is that the control algorithm represents the original nonlinear function that describes the dynamics of the proposed system. The controller model incorporates two cascaded subsystems: PD and PI fuzzy logic controllers. These two controllers regulate the attitude and …

Identification Of Geostationary Satellites Using Polarization Data From Unresolved Images, Andy Speicher

Electronic Theses and Dissertations

In order to protect critical military and commercial space assets, the United States Space Surveillance Network must have the ability to positively identify and characterize all space objects. Unfortunately, positive identification and characterization of space objects is a manual and labor intensive process today since even large telescopes cannot provide resolved images of most space objects. Since resolved images of geosynchronous satellites are not technically feasible with current technology, another method of distinguishing space objects was explored that exploits the polarization signature from unresolved images.

The objective of this study was to collect and analyze visible-spectrum polarization data from unresolved …

The Milton Lehman Papers, Milton Lehman

Finding Aids

Milton Lehman (1917-1966) was a free-lance writer, contributing about 250 articles to national magazines such as Saturday Evening Post, Life, Reader’s Digest, McCall’s, Look, The York Times, and other periodicals, books and newspapers. He wrote a biography of Robert H. Goddard that was published in 1963. He was helped throughout the seven year writing process by Esther C. Goddard, Goddard’s wife, who supplied him with transcripts of Goddard’s notes, notebooks, diaries, reports and correspondence and with photographs of his work as well as her own recollections. Lehman interviewed people from all parts of Goddard’s life; his childhood, schooling, early Clark …

Cavity Ignition In Supersonic Flow By Spark Discharge And Pulse Detonation, Timothy M. Ombrello, Campbell D. Carter, Chung-Jen Tam, Kuang-Yu Hsu

United States Air Force: Publications

Ignition of an ethylene fueled cavity in a supersonic flow was achieved through the application of two energy deposition techniques: a spark discharge and pulse detonator (PD). High-frequency shadowgraph and chemiluminescence imaging showed that the spark discharge ignition was passive with the ignition kernel and ensuing flame propagation following the cavity flowfield. The PD produced a high-pressure and temperature exhaust that allowed for ignition at lower tunnel temperatures and pressures than the spark discharge, but also caused significant disruption to the cavity flowfield dynamics. Under certain cavity fueling conditions a multiple regime ignition process occurred with the PD that led …

Absorption Properties Of Type-Ii Inas/Inassb Superlattices Measured By Spectroscopic Ellipsometry, P T. Webster, N A. Riordan, S Liu, E H. Steenbergen, R A. Synowicki, Y H. Zhang, S R. Johnson

United States Air Force: Publications

Strain-balanced InAs/InAsSb superlattices offer access to the mid- to long-wavelength infrared region with what is essentially a ternary material system at the GaSb lattice constant. The absorption coefficients of InAs/InAsSb superlattices grown by molecular beam epitaxy on (100)-oriented GaSb substrates are measured at room temperature over the 30 to 800 meV photon energy range using spectroscopic ellipsometry, and the miniband structure of each superlattice is calculated using a Kronig-Penney model. The InAs/InAsSb conduction band offset is used as a fitting parameter to align the calculated superlattice ground state transition energy to the measured absorption onset at room temperature and to …