Aerospace Engineering Commons^™

Task Optimization Utilizing Digital Transformation Concepts - Automation Project Execution Via Agile Methodology, Anthony Steven Maiello

Theses and Dissertations

Task Optimization via the use of automated process improvements is becoming more widespread as more industries lean into the concepts surrounding digital transformation. This shift also necessitates a complementary adaptation in project management methodologies to support the rapid and ever-changing environment, requirements, and innovations. This thesis examines the effectiveness of Agile methodology in managing digital automation projects, with a specific focus placed on process improvements with systems engineering. It accomplished this by contrasting the original model, designed and derived utilizing traditional project management techniques, with the proposed model which is a direct result of the application of Agile project practices. …

Stability And Control Flight Testing Of A Modified Cessna 172, Tatiana Dirrigl Forbes

Theses and Dissertations

The Cessna 172N is a small, fixed-wing, single-engine aircraft. The modified Cessna 172N included a swapped engine to a Lycoming O-360-A4M, tuned exhaust, and variable timing ignition installed. Test flights on this aircraft were performed order to evaluate the stability and control characteristics of the Cessna 172N, and compare them with the regulations in the Title 14 CFR Part 23 Airworthiness Standards for Normal, Utility, Acrobatic, and Commuter Category Airplanes. The flight test consisted of four separate tests performed during a single flight, departing from and returning to Melbourne Orlando International airport (KMLB). The data was collected through static and …

Optimization Of High-Order Statistical Moment Combinations To Best Represent Spray Flow Particle Probability Density Functions, Amanda Lynn Myers

Theses and Dissertations

Characterizing spray flows has been an issue of interest for years, particularly in regards to fuel injection in engines. Droplet velocity and diameter, among other characteristics, are crucial to understanding spray flows. One approach for determining these quantities in a spray is using a statistical approach that solves for the moments of droplet characteristics as they evolve in space and time. A theoretical probability density function (PDF) can be formulated using various combinations of moments which evolve according to derived moment transport equations (thus evolving the PDF), using the principle of maximum entropy as closure to the system. Building upon …

Accelerating Machine Learning Inference For Satellite Component Feature Extraction Using Fpgas., Andrew Ekblad

Theses and Dissertations

Running computer vision algorithms requires complex devices with lots of computing power, these types of devices are not well suited for space deployment. The harsh radiation environment and limited power budgets have hindered the ability of running advanced computer vision algorithms in space. This problem makes running an on-orbit servicing detection algorithm very difficult. This work proposes using a low powered FPGA to accelerate the computer vision algorithms that enable satellite component feature extraction. This work uses AMD/Xilinx’s Zynq SoC and DPU IP to run model inference. Experiments in this work centered around improving model post processing by creating implementations …

Marss: Multi-Agent Reinforcement Learning For Satellite Swarms, Nicholas J. Yielding

Theses and Dissertations

Multi-agent systems and swarms in spacecraft formation flying are of ever-increasing importance in a contested space environment—use of multiple spacecraft to contribute to a cooperative mission potentially increases positive outcomes on orbit, while autonomy becomes an ever more important requirement to reduce reaction time in dynamic situations and lower the burden on space operators. This research explores difficult swarm Guidance Navigation and Control (GNC) scenarios using Deep Reinforcement Learning (DRL). DRL polices are trained to provide guidance inputs to agents in multi-agent swarm environments for completing complex, teamwork focused objectives in geosynchronous orbit. An example scenario is explored for a …

A New Algorithm For Encounter Generation: Encounters From Actual Trajectories (Enact), James Anthony Ritchie Iii

Theses and Dissertations

There is ongoing research at the Federal Aviation Administration (FAA) and other private industries to examine a concept for delegated separation in multiple classes of airspace to allow unmanned aircraft systems (UAS) to remain well clear of other aircraft. Detect and Avoid (DAA) capabilities are one potential technology being examined to maintain separation. To evaluate these DAA capabilities, input traffic scenarios are needed, but current approaches are limited by the breadth of the traffic recordings available. This thesis derives a new mathematical algorithm that uses great circle navigation equations in an Earth spherical model and an accurate aircraft performance model …

Uncertainty Quantification And Constraint Of Chemical Kinetic Mechanisms Based On Flow Reactor Experiments, Ana Victoria Kock

Theses and Dissertations

The chemical kinetic model is one of key sub-models for computational fluid dynamics (CFD) simulation for optimizing and designing various combustors/engines. Detailed chemical kinetic models can consist of hundreds of species and thousands of elementary reaction steps. Considering the complexity in these detailed chemical kinetic models, it is important to quantify and minimize the uncertainties in the kinetic parameters. The uncertainties in the kinetic models can then be compared to uncertainties tied to experimental measurements. This approach has been frequently applied for relatively simple combustion parameters (e.g., laminar flame speed, ignition delay time), however it has not been well utilized …

Design Of A Test Frame And Its Corresponding Test Methods For A Deployable Composite Boom, William Luther Montgomery

Theses and Dissertations

Deployable composite booms (DCB) are an advanced class of support beams growing in applications including solar collectors and solar sails. DCBs can be coiled or folded into a compact footprint and the ability to be deployed, and in some design, concepts redeployed, making them optimal components for aerospace where weight and volume are finite resources. DCBs are a cutting-edge technology that has yet to be perfected with a need for longer booms with increased stiffnesses to accommodate the latest proposed designs. Atomic-6 has proposed a 16-foot boom manufactured using an autoclave process which aims to reach the goal of producing …

Uav-Deployable Sensing Network For Rapid Structural Health Monitoring, Joud Satme

Theses and Dissertations

Natural disasters and extreme weather events pose significant threats to the structural integrity and safety of civil and environmental infrastructure. In this context, Structural Health Monitoring (SHM) emerges as a pivotal discipline, intersecting engineering, technology, and disaster resilience. SHM's mission is to provide real-time, data-driven insights into the condition of critical infrastructure, encompassing bridges, buildings, dams, and transportation networks. These systems not only expedite assessment, but also wield substantial influence in mitigating catastrophic disasters. As the frequency and intensity of extreme weather conditions escalate due to climate change, the need for robust and proactive SHM strategies becomes increasingly apparent. Moreover, …

Pattern-Of-Life Modeling With Automatic Dependent Surveillance-Broadcast (Ads-B), Sarah J. Bolton

Theses and Dissertations

This dissertation and research were sponsored by the Air Force Research Laboratory Layered Sensing Exploitation Branch (AFRL/RYA) to investigate the utility of using the data found within aircraft secondary radar to make predictions about aircraft characteristics and intent. The research focuses on making predictions on aircraft characteristics using only the kinetic data within one type of secondary radar, Automatic Dependent Surveillance-Broadcast (ADS-B), as a surrogate for primary radar. The results from this research provide a means to reduce the reliance on a type of aircraft tracking that is vulnerable to cyber attack and other integrity concerns.

Gas Permeability Of 3d Stitched Composites For Cryogenic Applications, Shuvam Saha

Theses and Dissertations

This research aims to investigate the influence of 3D through-thickness stitching on the gas permeability and transverse microcracking of cryogenically cycled carbon/epoxy composites. 3D through-thickness stitching can be used to improve the interlaminar properties of polymer matrix composites (PMCs) and produce lightweight, unitized structures for cryogenic storage tanks. To fully utilize stitched composite structures for these applications, their inherent gas permeability challenges must be understood. Therefore, in this study, the stitched composites' damage evolution and gas permeability was experimentally characterized under a) pure thermal stress, b) thermal and uniaxial mechanical stress, and c) thermal and biaxial mechanical stress. Helium gas …

Application Of An Adaptive Controller On An Air-Bearing Vehicle-Manipulator System, Samuel Thomas Lovelace

Theses and Dissertations

The growing demand for on-orbit servicing and assembly as well as orbital debris capture and removal poses many engineering challenges. One primary challenge is that of position and attitude control of a spacecraft-manipulator system while performing these operations. Standard control approaches may be used for cases where the dynamics of the objects that the spacecraft-manipulator system interacts with are known are still plausible. However, there will likely be some uncertainty and lack of knowledge of the dynamic properties of orbital debris and parts required for servicing. Therefore, many have proposed the use of adaptive control schemes which can recalculate the …

Analysis Of The Performance, Recertification, And Sustainability Of A Cessna 172n Modified With An O-360-A4m Powerplant, Variable Timing Electronic Ignition, And Tuned Exhaust, Kelsey Lee Kaht

Theses and Dissertations

The purpose of this thesis is to discuss the performance, modification, and recertification of the test aircraft, a Cessna 172N that has been equipped with an O-360-A4M power plant, tuned exhaust, and variable timing electronic ignition, and to compare the aircraft to a stock aircraft and other high-performance aircraft to determine the feasibility of the modifications. 65 knot, 80 knot, and 95 knot steady state climb and 2000 ft and 5000 ft level acceleration tests were performed with the test aircraft at the Melbourne Orlando International Airport. The weather was clear with calm wind, and there was only one issue …

Design And Analysis Of Asymmetric “String-Of-Pearls” Common Repeating-Ground-Track Satellite Constellations For Missions Requiring Regional Coverage, Nathaniel Choo

Theses and Dissertations

Satellite constellation design must balance many factors that emerge from multiple sources, including environmental hazards and competing mission objectives. The dynamic nature of space systems makes the problem of ‘optimal’ satellite constellation design even more challenging. Restricting satellite constellation designs to predefined geometric frameworks can alleviate many challenges associated with the design problem; however, it raises an important question: which geometric framework performs best for each mission set? This research leverages simulations, metaheuristics, and mathematical programming techniques to address this question for missions focusing on Earth-observation of one or more regions.

First, this research captures the current state of satellite …

Effects Of Alternative Jet Fuels On Aerospace-Grade Composites: Experimental And Modeling Studies, Naoufal Harich

Theses and Dissertations

The aviation industry aims to reduce its environmental impact through innovation and research. The usage of composite materials for multiple primary structures represents one such measure. Several alternative fuels were approved and used along with the Federal Aviation Administration (FAA). These alternative fuels are produced from wastes and biomasses. Some alternative fuels were initially only approved as drop-in fuels, meaning they must be blended with conventional fuels to operate. Fuel tanks are usually embedded into the wing structure, which is mainly made of composite materials. These composites tend to absorb fluids it encounters through their matrix phase. The absorption behavior …

Developing Systems Engineering And Machine Learning Frameworks For The Improvement Of Aviation Maintenance, Fatine Elakramine

Theses and Dissertations

This dissertation develops systems engineering and machine learning models for aviation maintenance support. With the constant increase in demand for air travel, aviation organizations compete to maintain airworthy aircraft to ensure the safety of passengers. Given the importance of aircraft safety, the aviation sector constantly needs technologies to enhance the maintenance experience, ensure system safety, and limit aircraft downtime. Based on the current literature, the aviation maintenance sector still relies on outdated technologies to maintain aircraft maintenance documentation, including paper-based technical orders. Aviation maintenance documentation contains a mixture of structured and unstructured technical text, mainly inputted by operators, making them …

Evaluation Of Early Maturing Cultivars, Optimal Harvest Timing, And Canopy Reflectance Of Peanut To Maximize Grade And Yield, Joseph Bryan Whittenton

Theses and Dissertations

Peanut digging timing is difficult to predict due to indeterminate growth and peanut pods maturing underground, resulting in the need to research methods that provide consistent measurements, while reducing time and effort for farmers and researchers. Experiments were conducted to evaluate the accuracy of the Maturity Index 1 and Maturity Index 2 in predicting peanut grade, the accuracy of the North Carolina 2 degree day method in predicting peanut yield, and remote sensing vegetative indices sensitivity equivalence (SEq) to peanut Maturity Index 2 and harvest grade (TSMK) for cultivars IPG-914 and Georgia-06G in Mississippi.

Maturity Index 1 and …

Accident Investigation On In-Flight Loss Of Control Due To Configuration Change On Piper Arrow, Basilio Caruso

Theses and Dissertations

Between 2012 and 2021, NTSB has identified over 2200 accidents due to loss of control. The majority of which happened while flying in the pattern. The most challenging phase of a flight is the take-off and landing. During these phases, the pilot initiates a change of configuration of the airplane by lowering or retracting the flaps. Lowering the flaps slows down the plane and increases the lift of the wing but also changes the longitudinal free response of the aircraft. The pitch changes of the plane require the pilot to promptly compensate to keep straight and level flight and avoid …

A Study To Determine Performance Characteristics Of The Mississippi Cowling - Piper Archer Vs. Piper Warrior, Zilvinas Visockas

Theses and Dissertations

Today, aviation is one of the most technologically advanced and innovative sectors in the world. With fast-depleting natural resources, increasing environmental pollution, and continuous growth in fuel cost, efficiency has become industry’s top priority. Engineers are making gradual improvements that offer overall increase in aircraft’s performance. Drag is critical factor in aviation as it directly impacts aircraft’s fuel efficiency, range, and speed. During the design phase, engineers invest significant effort and expense in attempting to minimize the drag profile by implementing aerodynamic shapes and constantly reducing component weights. One of the real-life examples of such engineering attempts is Piper Archer, …

Smartphone Video Guidance Sensor In High-Altitude Uav Precision Landing, Joao Leonardo Silva Cotta

Theses and Dissertations

The Smartphone Video Guidance Sensor (SVGS) is an emerging technology developed by NASA Marshall Space Flight Center that uses a vision-based approach to accurately estimate the six-state position and orientation vectors of an illuminated target of known dimensions with respect to a coordinate frame fixed to the camera. SVGS is a software-based sensor that can be deployed using a host platform’s resources (CPU and camera) for proximity operations and formation flight of drones or spacecraft. The SVGS output is calculated based on photogrammetric analysis of the light blobs in each image; its accuracy in linear and angular motion at different …

Rendezvous And Proximity Operations In Cis-Lunar Space, Khalid Jebari

Theses and Dissertations

As interest in Moon exploration grows and efforts to establish an orbiting outpost intensify, accurate modeling of spacecraft dynamics in cis-lunar space is becoming increasingly important. Contrary to satellites in Low Earth Orbit (LEO) where it takes around 5 ms to communicate back and forth with a ground station, in the Moon’s orbit it can take up to 2.4 seconds to do so. This delay in communication can make the difference between a successful docking and a catastrophic collision for a remotely controlled satellite. Moreover, due to the unstable nature of trajectories in cis-lunar space, it is necessary to design …

Trajectory Energy Management For Ectol: Examination Of Battery Discharge Under Two Flight Profiles, Denner Campos Cunha

Theses and Dissertations

The expanding industry of electric airplanes presents a significant regulatory challenge for aviation authorities worldwide. The first step towards achieving a precise Trajectory Energy Management (TEM) is to understand how the powertrain behaves during the operation. Therefore, this work examined the battery performance of an eCTOL, the Pipistrel Velis Electro, under two different prescribed flight profiles and take-off weights. Flight 1, a destination trip profile, was conducted with a gross weight of 1146 lbs and a constant power setting of 22 kW during the cruise segment, while Flight 2, a local training flight profile, was conducted with a gross weight …

Flight Test Evaluation Of The B-1b Lancer For The Heavy Bomber Mission, Robert William Gates

Theses and Dissertations

Copyright held by author

Determining Performance Characteristics From The Mississippi Cowling - Piper Warrior Vs. Piper Archer, Soufiane Ait Yahia

Theses and Dissertations

Today, Piper is one of the most used aircraft in the general aviation sector. The history of Piper Aircraft has been the subject of numerous books and research projects with over 80 years of aviation industry leadership. For aviation fanatics, the Cherokee is synonymous with Piper Aircraft Corporation. The Piper PA-28 Cherokee is a family of two-seat or four-seat light aircraft built for air taxi, flight training, and personal use. The original Piper Cherokees PA-28- 150 and PA-28-160 received their type certificate from the Federal Aviation Administration back in 1960 and the series remains in production to this day. Multiple …

Climb Performance Testing Of The Pa-28-180 Utilizing Saw-Tooth Method And Level Acceleration Method, Paige Elizabeth Christensen

Theses and Dissertations

This thesis details the test methods, data reduction methods, and flight data analysis conducted in the climb performance evaluation of the PA-28-180 “Piper Arrow.” The main objective of this thesis was to quantitatively compare the climb performance requirements detailed in the former regulation, CAR 3.85a to the current regulation, 14 CFR 23.2120, utilizing Saw-Tooth steady climb method conducted at various airspeeds. The report also evaluates the Level Acceleration method at reciprocating headings, and qualitatively assesses the usefulness of testing multiple headings on a general aviation aircraft at multiple altitudes. The Saw-Tooth Climb and Level Acceleration flights were conducted on January …

The Effect Of Biodiesel Blend Composition On Jet Aircraft Airframe Fuel System Components & Materials, Elise Aurora Medhus

Theses and Dissertations

In the aviation industry, biodiesel is a clean-burning alternative to petroleum-based jet fuel and has been shown to reduce particle emissions from aircraft engines. This thesis studies the impact of biodiesel on aircraft airframe fuel system components & materials with corrosion-resistant surface treatments. The goal is to identify areas for optimization to increase the use of higher blends in jet aircraft engines to further reduce emissions. The work performed involved testing the corrosion resistance of several aluminum samples, steel samples, and non-metallic materials in numerous biodiesel blends ranging from B05 to B100. The testing method used was the Assessment of …

Modeling Of Turbulent Flow In Pipe Systems With Compound Bends, Stella Smithe

Theses and Dissertations

A practical CFD k-epsilon realizable model is applied to four pipe systems with various 90° bend configurations to examine velocity profile evolution and total pressure losses within the pipe systems. The pipe systems compared are a configuration with a single 90° L-bend, as well as three additional pipe configurations composed of dual 90° bends, all with total length x/D=16.7. The dual bend configurations studied are: a 180° turning U-bend, a 0° total turning S-bend, and a dual 90° out-of-plane, compound C-bend. The CFD model was benchmarked against experimental data from a straight pipe and a pipe configuration with a single …

Evaluation Of Preferential Vaporization Characteristics Of Isolated Single Droplet Combustion In A Converging Channel, Claire Elizabeth Dixon

Theses and Dissertations

Preferential vaporization of isolated single droplets was evaluated in this study. A previously verified lab-scale experiment using flow acceleration to counteract the effects of buoyancy in a converging channel with a decreasing cross section was utilized to investigate the single isolated droplet combustion. The previous experimentation revealed differences between results and values predicted by a one-dimensional numerical simulation. To investigate if the observed differences were the result of turbulent flow and the development of a boundary layer within the channel, a model was designed and analyzed in Ansys Fluent.

The developed Ansys simulation indicated that turbulent flow and growth of …

Actuation And Sensing Applications Of Piezoelectric Transducers, Connor Griffin

Theses and Dissertations

Piezoelectric materials, defined by their ability to display a charge across their surface in response to mechanical strain, are great for use in actuation and sensing applications. Actuation applications include acoustic devices, motors and vibration damping while sensing applications include pressure sensors, medical devices, energy harvesting and structural health monitoring (SHM). The use of piezoelectric actuation and sensing across the lifecycle of aerospace metals is currently an expanding field with use cases beginning with the manufacturing process and ending with SHM.

The research presented in this thesis had three goals: (i) to develop methods for implementation of piezoelectric actuation in …

Design Of A Miniaturized Cubesat Tt&C Patch Antenna, Thomas A. Butterick

Theses and Dissertations

This effort explored the design of miniaturized rectangular microstrip patch antennas for application as a telemetry, tracking, and control (TT&C) on a CubeSat. The motivation for this research was the Grissom-P CubeSat mission planned by AFIT. The TT&C antenna selected for the mission exceeded the allotted size by over a factor of two. The studies performed included analyses of simply reducing aperture size, altering substrate permittivity, and layered approaches to antenna miniaturization. The primary approach to miniaturization was based on a virtually shorted patch antenna. Other approaches included an edge-shorted, slotted patch and the use of corner truncations for improved …