Aerospace Engineering Commons^™

Technology: The Air And Space Force's Barrier To Innovation, William F. Cosgrove

Space and Defense

The Department of Defense is a rank-and-file institution that values orders adherence and a zero-error mentality, which has led commanders to be risk averse. This is exemplified in the cybersecurity realm, with controls attempting to protect all information, including uncontrolled unclassified information. Efforts that attempt to employ a new or different type of information technology are made very difficult by a number of existing policies. Additionally, customer surveys, service initiatives, and open user complaints have revealed dissatisfaction with Department of the Air Force (DAF) IT services. The millennial and post-millennial generations are the most technologically adept, yet the majority of …

A Great Nuclear Rejuvenation: What China Can Do With An Expanded Nuclear Arsenal, Grant Van Robays, Chloe Reynolds, Will Jackson, Tom Hammerle

Space and Defense

China's hypersonic glide vehicle test in October 2021 prompted widespread concern in the general public and within the defense intelligence community. General Mark A. Milley, Chairman of the Joint Chiefs of Staff, said the test was "very close" to a Sputnik moment.1 More than mere power projection by the People's Republic of China (PRC) and Chinese Communist Party ( CCP), the hypersonic test is an exemplification of rapid advancements in Chinese strategic nuclear forces writ large. Improved nuclear weapons capabilities will offer Beijing greater leverage in regional and international disputes with an increased capacity to coerce and compel adversaries into …

Editor's Note, Michelle Black

Space and Defense

No abstract provided.

Table Of Contents, Space And Defense

Space and Defense

Table of contents for Volume 14 issue 1 of Space and Defense

Front Matter, Space And Defense

Space and Defense

No abstract provided.

How Education Sats Started & A Youth Amsat-Na Program Proposal, Robert J. Twiggs, Nick Pugh

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "How Education Sats Started & A Youth Amsat-NA Program Proposal" from October 21, 2023.

Uas Risk Analysis In And Around Airports, Prasad Pothana, Jack Thornby, Michael Ullrich, Sreejith Vidhyadharan, Paul Snyder

Petroleum Engineering Posters and Presentations

No abstract provided.

State Space Modeling And Estimation Of Flexible Structure Using The Theory Of Functional Connections, Carlo Lombardi, Riccardo Bevilacqua

Student Works

In this work, we present a novel method to model the dynamics of a continuous structure based on measurements taken at discrete points. The method is conceived to provide new instruments to address the problem of flexible dynamics modeling in a spacecraft, where an effective mathematical representation of the non-rigid behavior of the is of critical importance in the design of an effective and reliable attitude estimation and control system. Both the measurements and the model that describes the structure can be affected by uncertainty. The purpose of the developed method is to estimate the position and the velocity of …

Stability Of Deep Neural Networks For Feedback-Optimal Pinpoint Landings, Omkar S. Mulekar, Hancheol Cho, Riccardo Bevilacqua

Student Works

The ability to certify systems driven by neural networks is crucial for future rollouts of machine learning technologies in aerospace applications. In this study, the neural networks are used to represent a fuel-optimal feedback controller for two different 3-degree-of-freedom pinpoint landing problems. It is shown that the standard sum-ofsquares Lyapunov candidate is too restrictive to assess the stability of systems with fuel-optimal control profiles. Instead, a parametric Lyapunov candidate (i.e. a neural network) can be trained to sufficiently evaluate the closed-loop stability of fuel-optimal control profiles. Then, a stability-constrained imitation learning method is applied, which simultaneously trains a neural network …

Using Machine Learning To Predict Hypervelocity Fragment Propagation Of Space Debris Collisions, Katharine Larsen, Riccardo Bevilacqua

Student Works

The future of spaceflight is threatened by the increasing amount of space debris, especially in the near-Earth environment. To continue operations, accurate characterization of hypervelocity fragment propagation following collisions and explosions is imperative. While large debris particles can be tracked by current methods, small particles are often missed. This paper presents a method to estimate fragment fly-out properties, such as fragment, velocity, and mass distributions, using machine learning. Previous work was performed on terrestrial data and associated simulations representing space debris collisions. The fragmentation of high-velocity fragmentation can be modeled by terrestrial fragmentation tests, such as static detonations. Recently, stereoscopic …

Communicating The Need To Communicate - Lessons Learned From Failure Point To A Need For Systems Perspectives, Calvin J. Fong, Elizabeth Matranga, Dianne J. Deturris

College of Engineering Summer Undergraduate Research Program

Failure investigation reports indicate that a systems perspective is needed to reduce failure in aerospace missions.

The failures occurred not because of a technical problem but because not enough communication was occurring.

Additive Manufacturing And Characterization Of Auxetic Structures, Jayesh P. Moore, Stephanie R. Ruzicka

College of Engineering Summer Undergraduate Research Program

An auxetic structure is an arrangement of unit cells that under a uniaxial load experiences expansion in both the longitudinal and transverse directions, resulting in a negative Poisson’s ratio (NPR). Research in auxetics has led to new insights into how non-linear mechanical reactions can be applied to various engineering fields. This project utilized stereolithography (SLA) 3D printing to manufacture auxetic test specimens to analyze of geometry-driven NPRs. With the distinctive mechanical properties of auxetic structures and vast applications, the future of product development of these geometries seems promising.

Hardware-In-The-Loop Reaction Wheel Testbed With Camera Vision, Abigail Romero, Harvey Perkins, Stephen Kwok-Choon

College of Engineering Summer Undergraduate Research Program

Reaction wheels are widely used in aerospace systems as a method of attitude control. This research was focused on the design, development, and testing of a hardware-in-the-loop reaction wheel testbed that can be used for research and teaching applications related to satellite navigation and control. This project successfully utilized commercial off-the-shelf components to develop a reaction wheel capable of controlling the orientation of a freely rotating platform, as well as tracking objects using computer vision.

Mechanical Design And Fabrication Of Rotating Test Stand For Supersonic Wind Tunnel, Suren I. Sanai, Sam Groom, Peter Kim, Nandeesh Hiremath

College of Engineering Summer Undergraduate Research Program

This research project focuses on the design and manufacturing of a rotating test stand for the Cal Poly Supersonic Wind Tunnel (SSWT). In order to establish essential design parameters, the project employs compressible flow isentropic relationships to calculate the Mach number within the test section and determine static pressures. This comprehensive effort integrates preliminary design and manufacturing processes, utilizing CAD designs and a range of machinery for component fabrication, while also highlighting initial testing of the rotating test stand's ability to withstand predicted aerodynamic loads. As part of the research's future work, rigorous structural stability testing and the implementation of …

Development Of User Interface And Testing Harness, Jacob Amezquita, William Albertini

College of Engineering Summer Undergraduate Research Program

No abstract provided.

Interfacial Thermomechanical Behavior Of Hybrid Carbon Fibers, Sriraj Srihari

Doctoral Dissertations and Master's Theses

The carbon fiber/epoxy interface is of great importance in composite design due to its load transfer mechanisms from the weak epoxy to the stronger fiber. Improving the strength of the interface reduces the risk of failure at the interface and improves the load transfer to the fiber. In this study, two types of nano-species ZnO nanowires and nickel-based metal organic frameworks were grown on carbon fibers to improve the interfaces. The interfacial mechanics of the enhanced fibers are evaluated using nanoindentation studies. Composite samples with Aeropoxy matrix and vertically aligned fibers are fabricated for this purpose. A Bruker TI-980 TriboIndenter …

Online Aircraft System Identification Using A Novel Parameter Informed Reinforcement Learning Method, Nathan Schaff

Doctoral Dissertations and Master's Theses

This thesis presents the development and analysis of a novel method for training reinforcement learning neural networks for online aircraft system identification of multiple similar linear systems, such as all fixed wing aircraft. This approach, termed Parameter Informed Reinforcement Learning (PIRL), dictates that reinforcement learning neural networks should be trained using input and output trajectory/history data as is convention; however, the PIRL method also includes any known and relevant aircraft parameters, such as airspeed, altitude, center of gravity location and/or others. Through this, the PIRL Agent is better suited to identify novel/test-set aircraft.

First, the PIRL method is applied to …

Switching Methods For Three-Dimensional Rotational Dynamics Using Modified Rodrigues Parameters, Matthew Jarrett Banks

Mechanical & Aerospace Engineering Theses & Dissertations

A rigid body in space has three degrees of rotational freedom. As a result, a minimum of three independent parameters is required to define the three-dimensional orientation of a rigid body. As is well known, every set of three independent parameters has at least one orientation where mathematical or geometrical singularities are encountered; therefore, when the use of a three-parameter representation is desired, a method for singularity avoidance must also be considered. A common practice for singularity avoidance is to switch between parameter sets whose singularities occur at different orientations. With this in mind, modified Rodrigues parameters (MRP) are considered …

Studies Of Flowfields And Dynamic Stability Characteristics Of A Quadrotor, Engin Baris

Mechanical & Aerospace Engineering Theses & Dissertations

Electric multirotor air vehicles have become a pervasive technology and research topic in industry, academia, and daily life, and small quadrotors are one of the most preferred designs in the multirotor marketplace. However, the configuration of the quadrotors makes aerodynamic interaction effects one of the key factors of the vehicle performance in both hover and non-axial forward flight conditions.

In the present work, aerodynamic characteristics of the cross-configured small quadrotor in hover, edgewise, and maneuvering flight modes were investigated in detail by performing static and dynamic wind tunnel tests at various RPM levels, wind speeds, pitch and yaw angles, and …

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, …

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 …

Rigid Body Constrained Motion Optimization And Control On Lie Groups And Their Tangent Bundles, Brennan S. Mccann

Doctoral Dissertations and Master's Theses

Rigid body motion requires formulations where rotational and translational motion are accounted for appropriately. Two Lie groups, the special orthogonal group SO(3) and the space of quaternions H, are commonly used to represent attitude. When considering rigid body pose, that is spacecraft position and attitude, the special Euclidean group SE(3) and the space of dual quaternions DH are frequently utilized. All these groups are Lie groups and Riemannian manifolds, and these identifications have profound implications for dynamics and controls. The trajectory optimization and optimal control problem on Riemannian manifolds presents significant opportunities for theoretical development. Riemannian optimization is an attractive …

The Investigation Of A Likely Scenario For Natural Tornado Genesis And Evolution From An Initial Instability Profile, Alexios Nicolas Philippou, Kakkattukuzhy M. Isaac

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A likely mechanism for the little-understood tornado genesis is proposed and its numerical implementation is presented. The Burgers-Rott vortex with its axis in the vertical direction is introduced as an instability mechanism, and the flow field then evolves under the influence of the atmospheric pressure, temperature and density variations with altitude. Buoyancy effects are implemented using the Boussinesq model. Results are presented and discussed for a set of conditions including mesh type and size, different turbulence models, and a few different boundary conditions. Post-processed results of the transient simulations including animations contain a wealth of information to help analyze tornado …

The Effect Of Through Thickness Reinforcement Angle On The Disbonding Behavior In Skin-Stringer Configuration, Christopher John Morris

Mechanical & Aerospace Engineering Theses & Dissertations

Post-cure through thickness reinforcement is a method used to increase the mechanical properties of composite laminates in the transverse direction. This study conducted a test on skin-stringer structures bonded together in three configurations using an epoxy or thermoplastic adhesive at the interface with reinforcing pins inserted through the laminate thickness located at the edge of the stringer at differing angles between -30º and 30º. The fabrication of these samples in configurations B and C consisted of the use of carbon fiber prepeg laminate at a ply orientation of [0₂90₂]_2s for the skin and [0 90] …

Atomic Insights Into The Structural Properties And Displacement Cascades In Ytterbium Titanate Pyrochlore (Yb2ti2o7) And High-Entropy Pyrochlores, M. Mustafa Azeem, Qingyu Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Pyrochlore oxides ((Formula presented.) are potential nuclear waste substrate materials due to their superior radiation resistance properties. We performed molecular dynamics simulations to study the structural properties and displacement cascades in ytterbium titanate pyrochlore ((Formula presented.)) and high-entropy alloys (HEPy), e.g., (Formula presented.), (Formula presented.), and (Formula presented.). We computed lattice constants (LC) ((Formula presented.)) and threshold displacement energy (Ed). Furthermore, the calculation for (Formula presented.) and ionic radius ((Formula presented.)) were performed by substituting a combination of cations at the A and B sites of the original pyrochlore structure. Our simulation results have demonstrated that the lattice constant is …

A Holistic Approach To Include Sic And Design The Optimal Extrudate Catalyst For Hydrogen Production–Reforming Routes, Ali M. Alkadhem, Fernanda Tavares, Natalia Realpe, Gontzal Lezcano, Arief Yudhanto, Mohammad Subah, Vasco Manaças, Jacek Osinski, Gilles Lubineau, Pedro Castaño

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Reforming processes are the backbone of hydrogen production routes, given the flexibility of their feedstock, such as methane, carbon dioxide, ammonia, waste plastics, or biomass. Heat transfer is a drawback at the industrial scale, reducing efficiency. We incorporate SiC in the technical composite, extrudate catalyst and develop a holistic approach to optimize and understand the effect of each constituent and its mixtures. We apply Ni-Ce as an active phase, bentonite or kaolin as a binder, alumina as a filler, and carborundum as the heat-transport carrier. We characterize the extrudate catalysts using various techniques, including crushing strength and thermal conductivity. We …

Faster, Cheaper, And Better Cfd: A Case For Machine Learning To Augment Reynolds-Averaged Navier-Stokes, John Peter Romano Ii

Mechanical & Aerospace Engineering Theses & Dissertations

In recent years, the field of machine learning (ML) has made significant advances, particularly through applying deep learning (DL) algorithms and artificial intelligence (AI). The literature shows several ways that ML may enhance the power of computational fluid dynamics (CFD) to improve its solution accuracy, reduce the needed computational resources and reduce overall simulation cost. ML techniques have also expanded the understanding of underlying flow physics and improved data capture from experimental fluid dynamics.

This dissertation presents an in-depth literature review and discusses ways the field of fluid dynamics has leveraged ML modeling to date. The author selects and describes …

Stafford Collection Review, The Conservation Center, Southwestern Oklahoma State University

Library Grants

This report evaluating the Thomas P. Stafford Collection has been made possible in part by a grant from the National Endowment for the Humanities.

Seeing Inside Shocked Plastic-Bonded Explosives, Dhanalakshmi Sellan, Lawrence Salvati, Siva Kumar Valluri, Dana D. Dlott, Xuan Zhou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A new method is described to study how microstructures within a plastic-bonded explosive (PBX) interact with shock waves to produce hot spots, and to identify the critical hot spots that grow into a deflagration. A unique feature of this method is that it allows us to see every crystal in the PBX during the shock. We used an HMX-based PBX fabricated into a wafer about one crystal thick so there are no crystals hidden from view. The wafer is embedded in a transparent polymer in a traveling wave geometry, and a microscope with a laser flyer launcher and a nanosecond …