Aerospace Engineering Commons^™

Computational Aerodynamics And Anatomical Characterization Of Laryngotracheal Stenosis In Children, William Poynot

LSU Master's Theses

Laryngotracheal stenosis (LTS) is a health condition in which an obstruction in the upper trachea can cause breathing difficulties and increased incidence of infection, among other symptoms. Occurring most commonly due to intubation in infants, LTS often requires corrective surgery. Currently, clinical methods of assessing the blockage region are simplistic and subjective, and it is challenging to determine the most effective surgical strategy for any given patient. In the present work, a comprehensive methodology is proposed for characterizing the stenosis region both in terms of its anatomical parameters and its corresponding aerodynamic properties. The combination of computational fluid dynamics (CFD) …

Julia Language Ephemeris And Physical Constants Reader For Solar System Bodies, Julia Mihaylov, Renee Spear

Undergraduate Research Symposium - Prescott

This presentation was the forerunner a second paper by the authors for the AAS/AIAA conference in January 2019, and is not available for download. For a description of the first presentation, see the authors' Discovery Day 2018 - Presentation.

Publicly released in 2012, the Julia language is a relatively new, open source dynamic language. One major benefit of Julia is its combined capabilities of both dynamic and static coding languages. It nearly matches the computational efficiency of static languages, such as FORTRAN or C, and exceeds that of dynamic languages, such as MATLAB or Python. Additionally, unlike Python, Julia …

Design Of A Heavy Lift Rc Aircraft - Society Of Automotive Engineers (Sae) Aero Design® West Competition Team, Jiyoung Hwang, Phillip Nielsen

Undergraduate Research Symposium - Prescott

The SAE Aero West design competition challenges undergraduate students to design and build an RC aircraft that will fly with the maximum number of passengers and luggage possible. The ERAU SAE team focuses on simulation-based research and project methods such as Computational Fluid Dynamics (CFD), aircraft optimization, and Finite Element Analysis (FEA). Designing and manufacturing a well-designed heavy lift aircraft and competing with other groups will give experience in solving engineering problems. The Aerodynamics team is currently focusing on score optimization, aircraft performance and configuration. The propulsion team is constructing a test rig to test various propellers and motors to …

Design Of A Thrust Stand For Low Power Electric Propulsion, John Norton

Undergraduate Research Symposium - Prescott

Electric propulsion (EP) has been gaining popularity due to the high efficiencies and specific impulse. These thrusters all follow the same general idea of converting stored electrical potential energy to kinetic energy for the craft; typically, this is accomplished by the acceleration of gas particles through three main methods, electrothermal, electromagnetic, and/or electrostatic. The specific impulse is the change of momentum per unit of propellant expended. While chemical propulsion produces a high change in momentum, they use much more propellant mass than an electric thruster. EP devices will typically produce very low thrust, which makes it difficult to measure thrust …

Eagle Aero Sport: Student-Built Aircraft, Rachael Bradshaw, Nick Bartholet

Undergraduate Research Symposium - Prescott

Eagle Aero Sport (EAS) is the first student operated aircraft build team at Embry-Riddle Aeronautical University. Our team allows students to gain hands-on experience in all aspects of aircraft production including: aircraft assembly, design engineering, management of production operations, finance, marketing, and team building skills. Through research, and consulting with the Experimental Aircraft Association, our airplane of choice is the Van’s RV-12. EAS is modifying the airplane to add real time flight test instrumentation for research. These instruments will gather data for aerodynamic, structural, as well as aircraft performance experiments. Presently, EAS is progressing with Build Team 60% complete and …

Investigation Of The Mechanical Behavior Of Non-Conventional Laminates: Anisotropy Of Tensile Strength In Coupons With Quasi-Isotropic Stiffness Characteristics, Israel Oluwatunmise Ayodele

Theses and Dissertations

Advanced composites have emerged as viable structural solutions over the years and have therefore become implemented in several applications, notably aerospace structures. In modern aircraft structures, they have been gradually introduced to both secondary and primary components. Laminated composites used in such applications have generally been restricted to those with straight fibers, that are aligned to only a handful of pre-selected fiber orientations; 0˚, 45˚, 90˚ and -45˚. Recent advances in the technology of laminated composites have however indicated the possibility to harness significantly higher structural gains by allowing the use of other fiber orientations, and even implementing curvilinear fibers …

Impulsive Dynamics And Control Of The Inertia-Wheel Pendulum, Nilay Kant, Ranjan Mukherjee

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The dynamics of the inertia-wheel pendulum, when subjected to impulsive inputs, can be described by algebraic equations. Optimal sequences of these inputs, that minimize their infinity norm, are designed for rest-to-rest maneuvers. The results are applied to the well-studied swing-up problem, and high-gain feedback is used for continuous approximation of the inputs and simulation of the impulsive dynamics. Analytical and simulation results establish a direct link between high wheel velocities during swing-up and control strategies that take the pendulum directly to the upright configuration. They also indicate that optimal trajectories resemble those of energy-based controllers and can be designed to …

Explosive Dust Test Vessel Comparison Using Pulverized Pittsburgh Coal, Jacob Miller, Jay Schafler, Phillip R. Mulligan, Robert Eades, Kyle A. Perry, Catherine E. Johnson

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Explosions of coal dust are a major safety concern within the coal mining industry. The explosion and subsequent fires caused by coal dust can result in significant property damage, loss of life in underground coal mines and damage to coal processing facilities. The United States Bureau of Mines conducted research on coal dust explosions until 1996 when it was dissolved. In the following years, the American Society for Testing and Materials (ASTM) developed a test standard, ASTM E1226, to provide a standard test method characterizing the “explosibility” of particulate solids of combustible materials suspended in air. The research presented herein …

Effects Of Nearwall Modeling In The Improved-Delayed-Detached-Eddy-Simulation (Iddes) Methodology, Rohit Saini, Nader Karimi, Lian Duan, Amsini Sadiki, Amirfarhang Mehdizadeh

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The present study aims to assess the effects of two different underlying RANS models on overall behavior of the IDDES methodology when applied to different flow configurations ranging from fully attached (plane channel flow) to separated flows (periodic hill flow). This includes investigating prediction accuracy of first and second order statistics, response to grid refinement, grey area dynamics and triggering mechanism. Further, several criteria have been investigated to assess reliability and quality of the methodology when operating in scale resolving mode. It turns out that irrespective of the near wall modeling strategy, the IDDES methodology does not satisfy all criteria …

Finite-Time Sliding Mode And Super-Twisting Control Of Fighter Aircraft, Kaushik Raj, Venkatesan Muthukumar, Sahjendra N. Singh, Keum W. Lee

Electrical & Computer Engineering Faculty Research

The development of two nonlinear robust higher-order flight control systems for roll-coupled maneuvers of fighter aircraft with uncertain parameters is discussed in this article. The objective is to independently control the output variables (roll angle, pitch angle and sideslip angle) using aileron, elevator and rudder control surfaces. For a nominal model of aircraft, first a finite time stabilizing (FTS) control law, based on the notion of geometric homogeneity, is designed. Then for robust control in the presence of parameter uncertainties, (i) a discontinuous sliding mode (DSM) control law and (ii) a super-twisting (STW) continuous control law is designed. It is …

A Heuristic Method For Task Selection In Persistent Isr Missions Using Autonomous Unmanned Aerial Vehicles, Christopher C. Olsen

Theses and Dissertations

The Persistent Intelligence, Surveillance, and Reconnaissance (PISR) problem seeks to provide timely collection and delivery of data from prioritized ISR tasks using an autonomous Unmanned Aerial Vehicle (UAV). In the literature, PISR is classified as a type of Vehicle Routing Problem (VRP), often called by other names such as persistent monitoring, persistent surveillance, and patrolling. The objective of PISR is to minimize the weighted revisit time to each task (called weighted latency) using an optimal task selection algorithm. In this research, we utilize the average weighted latency as our performance metric and investigate a method for task selection called the …

Floating Active Baffles, System And Method Of Slosh Damping Comprising The Same, Dae Won Kim, Rudy L. Baum, Vijay Santhanam, Balaji Sivasubramanian, Sathya Gangadharan

Publications

This disclosure provides a system for damping slosh of a liquid within a tank, a baffle for use in the system, and a method of damping slosh using the system. The system includes a plurality of baffles. Each baffle has a body configured to substantially float upon the liquid. Each baffle also has an activation material received along at least a portion of the body. The activation material is magnetically reactive provided in a quantity sufficient to enable the body to be manipulated in the presence of a magnetic field (M). The system further includes an actuator configured to pro­vide …

Telemetry Subsystem With Higher Access Duration For Leo Satellites, Jose L. Garcia

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Jose L. Garcia on September 10, 2018.

Techedsat 7 And 8-Nasa Missions For Earth Observation, Andrew Pham

STAR Program Research Presentations

Big results can come from small satellites, and Technology Educational Satellite 8 or TES-8 is the latest small satellite in the TechEdSat series from NASA Ames Research Center. TechEdSat is a collaborative program, in which advanced university students have a chance to work directly with researchers on NASA Space Projects. Thanks to the assistance of students from several universities around the country every year, TechEdSat has helped NASA develop Nano-satellite technologies and evaluate new ideas for future spacecraft. TES-8 is the eighth satellite of the continuing TechEdSat series. On December 01, 2018 TES-8 followed a Commercial Resupply Service mission to …

Self-Assembly Of Protein Fibrils In Microgravity, Dylan Bell

Theses and Dissertations

Deposits of insoluble protein fibrils in human tissue are associated with amyloidosis and neurodegenerative diseases. Different proteins are involved in each disease; all are soluble in their native conformation in vivo, but by molecular self-assembly, they all form insoluble protein fibril deposits with a similar cross -sheet structure. The study of molecular self-assembly is also of interest to origin of life. The development of cellular activity was dependent upon the creation of large complex molecular structures in the chemical and environmental conditions present when life originated. Although life probably arose in a planetary environment, microgravity is known to effect cellular …

Three-Dimensional Wall Effects In A Scramjet Cavity Flameholder, Evan P. Oren

Theses and Dissertations

Scramjets, or supersonic combustion ramjets, are a key component for the development of powered hypersonic vehicles. The flameholding strategy used in this engine creates a recirculation region by creating a cavity in one side of the combustor. This highly unsteady region is difficult to interrogate through conventional means. A novel optical observation technique called hyperspectral imaging has been developed to examine the scramjet combustion chamber. The hyperspectral camera is capable of generating an interferogram at hundreds to thousands of wavelengths. These data are integrated across the line-of-sight with no information on three-dimensional (3D) location of origin. A model must be …

Application Of Spectral Solution And Neural Network Techniques In Plasma Modeling For Electric Propulsion, Joseph R. Whitman

Theses and Dissertations

A solver for Poisson's equation was developed using the Radix-2 FFT method first invented by Carl Friedrich Gauss. Its performance was characterized using simulated data and identical boundary conditions to those found in a Hall Effect Thruster. The characterization showed errors below machine-zero with noise-free data, and above 20% noise-to-signal strength, the error increased linearly with the noise. This solver can be implemented into AFRL's plasma simulator, the Thermophysics Universal Research Framework (TURF) and used to quickly and accurately compute the electric field based on charge distributions. The validity of a machine learning approach and data-based complex system modeling approach …

Investigation Of A Pressure Wave Supercharger For An Industrial Diesel Engine, Brian A. Beasley

Theses and Dissertations

Internal combustion engines suffer from decreased performance as altitude is in- creased. This performance decrease can be overcome by increasing the pressure in the engine's intake manifold. Typically, this is accomplished with a turbocharger or supercharger. However, mechanical compression devices such as these suffer from decrease compression efficiency as the size of the device decreases. The size of the compression device scales with the amount of mass ow through the device, and the amount of mass ow is proportional to the size of the engine. This means a small turbocharger for a small engine is less efficient than a larger …

Navigation With Artificial Neural Networks, Joseph A. Curro Ii

Theses and Dissertations

The objective of this dissertation is to explore the applications for Artificial Neural Networks (ANNs) in the field of Navigation. The state of the art for ANNs has improved significantly so now they can rival and even surpass humans in problems once thought impossible. We present different methods to augment, combine, or replace existing Navigation filters with ANN. The main focus of these methods is to use as much existing knowledge as possible then use ANNs to extend the current knowledge base. Next, improvements are made for a class of Artificial Neural Network (ANN)s which provide covariance called Mixture Density …

Reconstruction Of The 3d Temperature And Species Concentration Spatial Distribution Of A Jet Engine Exhaust Plume Using An Infrared Fourier Transform Spectrometer Hyperspectral Imager, Mason D. Paulec

Theses and Dissertations

The measurement of combustion byproducts is useful for determining pollution of any fuel burning application, efficiency of combustion, and determining detectability of aircraft exhausts. Both intrusive and non-intrusive techniques have been utilized to measure these quantities. For the majority of the non-intrusive techniques, the absorption and emission spectra of the gases are utilized for measurements. For this research, the use of the Telops Infrared Fourier Transform Spectrometer (IFTS) Hyperspectral Imager (HSI) was explored within the scope of combustion diagnostic methods, as an option for remote measurements of a jet turbine to determine concentration of species and temperature of the combustion …

Simplex Control Methods For Robust Convergence Of Small Unmanned Aircraft Flight Trajectories In The Constrained Urban Environment, Michael D. Zollars

Theses and Dissertations

Constrained optimal control problems for Small Unmanned Aircraft Systems (SUAS) have long suffered from excessive computation times caused by a combination of constraint modeling techniques, the quality of the initial path solution provided to the optimal control solver, and improperly defining the bounds on system state variables, ultimately preventing implementation into real-time, on-board systems. In this research, a new hybrid approach is examined for real-time path planning of SUAS. During autonomous flight, a SUAS is tasked to traverse from one target region to a second target region while avoiding hard constraints consisting of building structures of an urban environment. Feasible …

Thermochemical Non-Equilibrium Models For Weakly Ionized Hypersonic Flows With Application To Slender-Body Wakes, Matthew P. Clarey

Theses and Dissertations

The current resurgence of interest in hypersonic technologies has warranted an inquiry into the commonly employed thermochemical non-equilibrium models within computational fluid dynamic (CFD) simulations. Additionally, research has historically focused on forebody flowfields, while studies of the complex wake structure have remained elusive. Although the forebody is of significance for vehicle analysis, the wake presents many exploitative characteristics. This dissertation aimed to address these two deficits. First, two three-temperature non-equilibrium models were developed, increasing the fidelity of hypersonic solutions above that of the legacy two-temperature model. The models were then investigated via zero-dimensional simulations, to detail the non-equilibrium processes, and …

Optimal Finite Thrust Guidance Methods For Constrained Satellite Proximity Operations Inspection Maneuvers, Eric R. Prince

Theses and Dissertations

Algorithms are developed to find optimal guidance for an inspector satellite operating nearby a resident space object (RSO). For a non-maneuvering RSO, methods are first developed for a satellite subject to maximum slew rates to conduct an initial inspection of an RSO, where the control variables include the throttle level and direction of the thrust. Second, methods are developed to optimally maneuver a satellite with on/off thrusters into a natural motion circumnavigation or teardrop trajectory, subject to lighting and collision constraints. It is shown that for on/off thrusters, a control sequence can be parameterized to a relatively small amount of …

Satellite Articulation Sensing Using Computer Vision, David H. Curtis

Theses and Dissertations

Autonomous on-orbit satellite servicing benefits from an inspector satellite that can gain as much information as possible about the primary satellite. This includes performance of articulated objects such as solar arrays, antennas, and sensors. A method for building an articulated model from monocular imagery using tracked feature points and the known relative inspection route is developed. Two methods are also developed for tracking the articulation of a satellite in real-time given an articulated model using both tracked feature points and image silhouettes. Performance is evaluated for multiple inspection routes and the effect of inspection route noise is assessed. Additionally, a …

Development And Application Of Quadratic Constitutive Relation And Transitional Crossflow Effects In The Wray-Agarwal Turbulence Model, Hakop Jack Nagapetyan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Computational Fluid Dynamics (CFD) has now become an almost indispensable tool for modern engineering analysis of fluid flow over aircrafts, turbomachinery, automobiles, and many other industrial applications. Accurate prediction of turbulent flows remains a challenging problem. The most popular approach for simulating turbulent flows in complex industrial applications is based on the solution of the Reynolds-Averaged Navier-Stokes (RANS) equations. RANS equations introduce the so called “Reynolds or turbulent stresses” which are generally modeled using the Boussinesq approximation known as “Turbulence modeling.” Despite their development over a century, the turbulence models used with RANS equations still need much improvement. The first …

Clean-Fuel E-Vtol Air Mobility Vehicles For Unmanned And Manned Operations, Larry D. Mccarroll, Brian Morrison, Bruce J. Holmes D.E., Faiaa, Fraes, Henry Vu

National Training Aircraft Symposium (NTAS)

Imagine for a moment, having your very own safe, affordable, clean-fuel, point-to-any point vehicle for travel in the 21st-century 3-dimensional airspace system. Your ultra-reliable e-VTOL allows commuters to leave behind the constraints of hub-and-spoke airports, and the congestion of interstates, turnpikes and freeways. Facilitating Inter- and Intra-urban travel, such as downtown-to-airport, or metropolis-to-metropolis, or home-to-work. Perfect for dense urban environments worldwide. And all while offering the clean power of hydrogen for zero-emission travel.

This vision for efficient, clean, delay-free mobility has been talked about for decades, but always waived aside as some kind of futurist vision. This future requires tackling …

Evaluating The Impact Of Nextgen’S Air Traffic System On Aviation Security, Linda V. Weiland, G. Wei

Publications

Networked Next Generation Air Transportation System (NextGen) opened the gate to digital National Airspace System (NAS) in cyberspace. Air traffic improvements from NextGen system, accompanied by the risk of long-standing cyberattack issue in information technology industry became an increasingly challenging matter to the aviation community and Air Traffic Management (ATM), as cybersecurity challenges in the NextGen system could affect NextGen's principle assurance of safety and security in air transportation. The technological shift of NAS infrastructure from traditional radar-based systems to networking system of systems leads to a review, revision and redefinition of current policies, standards regelations, cultures and norm to …

Quadrotor Swarm Arena (Quasar) Development Of A Swarm Control Testbed, Shane T. Stebler, William Mackunis

Beyond: Undergraduate Research Journal

Swarm control systems are increasingly popular in the robotics industry and academia due to their many potential applications. The goal of the Quadrotor Swarm Arena (QuaSAr) project is to construct a quadrotor swarm control testbed to provide researchers with the tools needed to experimentally investigate this emerging science. This testbed is equipped with a motion capture system, test control station, and numerous quadrotor UAVs. MATLAB-Simulink is utilized for control law development, data processing, and test control. This configuration allows researchers to test developing control law in a 'plug and play' manner as control development and test control are all completed …

An Analysis Of Harmonic Airloads Acting On Helicopter Rotor Blades, Iftekhar A. Riyad

LSU New Orleans Theses and Dissertations

Rotary wing aircrafts in any flight conditions suffer from excessive vibration which makes the passengers feel uncomfortable and causes fatigue failure in the structure. The main sources of vibration are the rotor harmonic airloads which originate primarily from the rapid variation of flow around the blade due to the vortex wake. In this thesis, a mathematical model is developed for rotor blades to compute the harmonic airloads at rotor blades for two flight conditions vertical takeoff and landing, and forward flight. The sectional lift, drag, and pitching moment are computed at a radial blade station for both flight conditions. The …

Remote Sensing Of Soil Moisture Using S-Band Signals Of Opportunity: Model Development And Experimental Validation, Marvin Jesse, Benjamin Nold, James L. Garrison

The Summer Undergraduate Research Fellowship (SURF) Symposium

Root zone soil moisture (RZSM) is a vital aspect in meteorology, hydrology, and agriculture. There are currently some methods in passive and active remote sensing at L-band, but these methods are limited to a sensing depth of approximately 10 cm. Observing RZSM (water in the top meter of soil) will require lower frequencies, thus presenting significant difficulties for a spaceborne instrument, because of the required antenna size, the presence of radio-frequency interference (RFI), and competition for spectrum allocations (in the case of active radar). Bistatic radar using Signal of Opportunity (SoOp) (e.g. digital satellite transmitters) provides an opportunity for remote …