Aerospace Engineering Commons^™

Additively Manufactured Flexible Piezoelectric Wave-Based Multifunctional Sensor, Rishikesh Srinivasaraghavan Govindarajan

Doctoral Dissertations and Master's Theses

The demand for acoustic wave-based sensors has rapidly increased in the aerospace, chemical, gas, and biological fields due to their versatility in sensing measurands. This study aims to develop a flexible piezoelectric sensor exhibiting enhanced piezoelectric properties using additive manufacturing techniques that can detect mechanical strains and gas or volatile organic compounds (VOCs) by incorporating functional material into the sensing layer. This research explores piezoelectric substrate fabrication through diverse additive manufacturing techniques, including new material development made of polymer/nano-fillers with electrodes that are filled using different printing techniques. Notably, the design of the interdigital transducer (IDT) in the piezoelectric sensor …

In Situ Synthesis, Characterization And Photocatalytic Efficacy Of Silver-Enhanced Mxene And Graphene Nanocomposites, Kishore Chand, M. Mustafa Azeem, Muhammad Nazim Lakhan, Mukhtiar Ahmed, Muhammad Jehanzaib Aslam, Ahmer Hussain Shah

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The emergence of 2D materials has significantly expanded the wide range of nanomaterials with diverse applications. Notably, their high conductivity, catalytic efficiency, and hydrophobicity have fueled heightened research interests for water treatment applications. This research aimed to investigate the synthesis and characterization of MXene and reduced graphene oxide (rGO) nanocomposites with silver nanoparticles (Ag) for enhanced catalytic activity in the decomposition of Direct Blue-24 dye. In this study, we employed well-established methods, previously documented in the literature, to prepare two distinct nanocomposites. Novel nanocomposites, namely reduced graphene oxide–silver nanoparticles (rGO–Ag) and MXene–silver nanoparticles (MXene–Ag), were synthesized using the hydrothermal and …

Flying Wing Aerodynamic Design And Airbrake Integration, Philip Lawson Mantz

Mechanical & Aerospace Engineering Theses & Dissertations

During the 2022-2023 Academic year, the defense contractor, AeroVironment, tasked the Unmanned Aerial Systems Laboratory at Old Dominion University with designing an autonomous drone platform. A brief summary of the aerodynamic requirements included that the drone should cruise at a target cruise speed of 30m/s, the drone would operate up to an altitude of 1500m and be able to land within a 20m radius of a designated landing spot. The laboratory chose a flying wing model. Additionally, the aircraft would have an airbrake system integrated into the platform.

The aerodynamic requirements were configurated through the use of a ‘constraint diagram’. …

Alternative Applications Of Composite Materials To Reduce Radar Cross Section, Mark Patterson

Mechanical & Aerospace Engineering Theses & Dissertations

The use of carbon nanoparticles and graphene in composite materials has created a foundational shift in enhancing performance across mechanical, thermal, and electrical properties. Such applications are vital in the aerospace industry. However, there has not been such a focus on the material use for reducing radar cross section (RCS). Historically, RCS is minimized by designing sharp geometric shapes to deflect or dissipate the incoming electromagnetic waves away from the receiving antenna. However, these designs are not always optimized for aerodynamics. The goal of this research is to understand the application of composite materials and specifically carbon nanotubes (CNTs) to …

A Study Of Directionality Effects In Three-Beam Coaxial Titanium Wire-Based Laser Metal Deposition, Remy Mathenia, Braden Mclain, Todd Sparks, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Coaxial wire-based laser metal deposition is a versatile and efficient additive process that can achieve a high deposition rate in the manufacturing of complex structures. In this paper, a three-beam coaxial wire system is studied, with particular attention given to the effects of the deposition direction and laser beam orientation on the resulting bead geometry symmetry. With the three-beam laser delivery, the laser spot pattern is not always symmetric with respect to the deposition direction. Single titanium beads are deposited in different directions and at varying deposition rates, and the bead profile is quantitatively scored for multiple symmetry measures. Through …

Analytical And Fem Models For Thermal Analysis And Residual Stresses Using Wire Arc-Based Welding And Additive Manufacturing Of Sus304, Muhammad Arif Mahmood, Usman Tariq, Mihai Oane, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Austenitic stainless steel, also known as SUS304, has a wide industrial application. The resultant residual stresses and deformation due to arc welding play a critical role in an in-service SUS04 part failure. Various experimental studies have been presented to predict residual stresses and part deformation. However, these techniques are expensive and time-consuming owing to the trial-and-error approach, limiting their application to industrial applications. Based on the emergent need, this study introduces two simulation models based on analytical and FEM techniques for thermal distribution and residual stress estimation. The experimentally calibrated models results have been implemented for SUS304 multi-pass arc welding. …

Engine Performance Of An Electric Airplane With Partial Battery Capability, Hannah Yasmine Scrivens

Theses and Dissertations

As electric aircraft are developed and certified, knowledge of electric aircraft performance during complete or partial battery failures can be useful to determine an aircraft’s limitations and capabilities of completing an emergency landing, especially during takeoff and low-altitude climbs, as well as fully characterizing the potential aircraft performance. The results of this research will be useful in developing regulations and procedures pertaining to energy reserves and emergencies. This paper presents the results of a Pipistrel electric airplane climb power ground test that was conducted by the author and Florida Tech faculty. In the test, one of the airplane’s batteries was …

Study On Pilot Response Time To Reject Takeoff With One Engine Inoperative (Oei), Lydia Savitri Scrivens

Theses and Dissertations

The FAA regulation 14 CFR § 25.109 defines accelerate-stop testing for transport-category multiengine aircraft. It specifies that testing must include 2-second distance equivalent at engine failure speed VEF to simulate time taken for pilot to reject takeoff. However, pilot response time is widely debated. The purpose of this study is to determine pilot response time in rejecting a takeoff due to the failure of one engine during the takeoff roll.

Seven multiengine rated pilots participated in this study, which was conducted in a Baron 58 in the X-Plane 12 flight simulator. During the recruiting process, test subject candidates provided their …

Using A Neural Network To Remove Noise From Images, Anvar Asatilloyevich Ravshanov

Chemical Technology, Control and Management

This article proposes modern approaches to the problem of noise reduction in images using neural networks and also analyses the possibilities of noise reduction using neural networks. The convolutional neural network model and the Mediana, Sobel filter were considered for image denoising. The quality improvement of the trained neural network and the comparison with classical noise reduction methods have been carried out.

Disk Engine With Circumferential Swirl Radial Combustor, Brian T. Bohan, Marc D. Polanka, Bennett Staton

AFIT Patents

A disk engine and system configured to provide high power at a reduced axial length is disclosed herein. The disk engine includes a radial compressor, a compressor discharge manifold positioned circumferentially about compressor, a combustion chamber positioned within the discharge manifold and a radial turbine positioned radially inward of the combustion chamber.

Sliding Mode Control With Chattering Reduction, Suryamshu Ramesh

Doctoral Dissertations and Master's Theses

Sliding Mode Control is a powerful nonlinear control methodology that can handle parametric uncertainties and external disturbances. However, the discontinuous and high-frequency switching nature of the control law introduces the chattering phenomenon, which leads to potential actuator degradation, alterations to the desired response characteristics and, sometimes, instability during control implementation. The main objective of this thesis is to study Sliding Mode Control with chattering reduction. The Sliding Mode Control law involves an equivalent control component and a discontinuous control component. A disturbance estimation is performed based on Lyapunov analysis and adaptive control techniques and then included in the control law …

Board 125: Work In Progress: Faculty Experiences And Learning Through Oral-Assessment Implementation In Engineering Courses, Minju Kim, Carolyn L. Sandoval, Josephine Relaford-Doyle, Torus Washington Ii, Saharnaz Baghdadchi, Nathan Delson, Marko Lubarda, Alex M. Phan, Curt Schurgers, Huihui Qi

Psychology Faculty Articles and Research

This WIP qualitative research paper explores faculty experiences with implementing oral exams in high-enrollment undergraduate engineering courses at a research university. With a primary goal to improve conceptual mastery, as well as a desire to ensure academic integrity in the sudden move to remote instruction at the height of the pandemic, a group of faculty in Mechanical and Aerospace Engineering and Electrical and Computer Engineering departments implemented oral assessments in their own engineering courses across several quarters. They formed a research group with educational developers in a teaching and learning center on campus, and investigated the impact of oral assessments …

Turbine Cooling System With Energy Separation, James L. Rutledge, Matthew N. Fuqua, Carol M. Bryant

AFIT Patents

A method and system for cooling an engine and/or vehicle using energy separation is disclosed herein. An energy separation device is operable for separating a compressed gaseous coolant stream into a first relatively cooler coolant flow stream and a second relatively hotter coolant flow stream. The relative cooler coolant flow stream is directed to a first region requiring increased cooling and the relative hotter coolant flow stream is directed to a second region requiring lower cooling than the first region in the engine or vehicle.

Using Dft On Ultrasound Measurements To Determine Patient-Specific Blood Flow Boundary Conditions For Computational Hemodynamics Of Intracranial Aneurysms, Hang Yi, Zifeng Yang, Luke Bramlage, Bryan Ludwig

Mechanical and Materials Engineering Faculty Publications

Boundary conditions (BCs) is one pivotal factor influencing the accuracy of hemodynamic predictions on intracranial aneurysms (IAs) using computational fluid dynamics (CFD) modeling. Unfortunately, a standard procedure to secure accurate BCs for hemodynamic modeling does not exist. To bridge such a knowledge gap, two representative patient-specific IA models (Case-I and Case-II) were reconstructed and their blood flow velocity waveforms in the internal carotid artery (ICA) were measured by ultrasonic techniques and modeled by discrete Fourier transform (DFT). Then, numerical investigations were conducted to explore the appropriate number of samples (N) for DFT modeling to secure the accurate BC by comparing …

F56: Rocket Thrust Vector Control, Ethan Douglas Anderson, Yiming Trent Jia, Sahil Sampat

Mechanical Engineering

This Final Design Review (FDR) report compiles relevant information regarding the Rocket Thrust Vector Control senior project as sponsored by Ethan Anderson from Cal Poly Space Systems (CPSS). Documented in this report is our progress from the months following our Critical Design Review (CDR) completion. This consists of a brief overview of the design our thrust vector control (TVC) system and its subassemblies with design changes noted, a thorough walkthrough of our procurement, manufacturing, and assembly process for creating our verification prototype (including software), a breakdown of how we verified each of our specifications through inspection and testing and the …

A Hardware-In-The-Loop Star Tracker Test Bed, Ashley Haraguchi

Master's Theses

As the use of small satellites for advanced space missions continues to grow, the importance of low mass and cost three-axis attitude stabilization systems increases as well, with these systems requiring high accuracy attitude knowledge. Star trackers provide the most accurate attitude knowledge of any type of attitude sensor, but the high cost, size, and weight of commercial star trackers can be prohibitive to small satellite missions. Many simple star trackers have been developed using commercial off-the-shelf camera sensors and processing hardware, but the challenge remains in testing and characterizing these devices. A common solution is night sky tests, in …

Automatic Mass Balancing Of A Spacecraft Attitude Dynamics Simulator With Six Sliding Masses, Amelia J. Gilman

Master's Theses

The goal of this thesis is to investigate automatic mass balancing methods for spacecraft attitude dynamics simulators, create a hardware design for a mass balancing system, and assemble the hardware on the Cal Poly Spacecraft Attitude Dynamics Simulator (SADS). Spacecraft attitude dynamics simulators replicate the torque-free environment of space with ground-based hardware. The SADS is mounted on a spherical air bearing, and includes a pyramid of four reaction wheels. The air bearing allows frictionless, unbounded rotation about the vertical axis, and 30 degrees about the horizontal axes. The torque-free configuration of the SADS can be used to test spacecraft attitude …

Improving Aerospace System Robustness Integration Of Singular Value Decomposition And Network Centrality, Ricardo S. Contreras

Master's Theses

This thesis presents an approach to understanding and enhancing the robustness of aerospace systems through the integration of network analysis, Design Structure Matrix (DSM), Singular Value Decomposition (SVD), and robustness simulation techniques. This methodology called the Importance Hierarchy method, provides a comprehensive framework for decomposing the interactions of aerospace systems, focusing on identifying and evaluating critical components and interactions.

The Importance Hierarchy method was used to study the Autonomous Flight Termination Unit (AFTU) by analyzing its components and interdependencies. The AFTU was selected because it recently completed a Preliminary Design Review (PDR), and its design and operational functions were well-known. …

Rover On A Chip (Roach) Debris Utility & Solar Shell Technology (Dusst), Joshua Aaron Tuttobene, Jacquelyn Rose Banh, Nathan Christopher Chapman, Tanner Casey Wells

Mechanical Engineering

The Rover on A Chip project’s Debris Utility and Solar Shell Technology team’s final design is outlined in this document. Starting with the design of our system, this document highlights important progress made since the Critical Design Review and fully describes our final design and verification of our final prototype. We then justify these design choices by testing multiple functionalities and conditions to ensure they will meet all of our specifications. Next, we describe in detail our procurement manufacturing method for the project. Lastly, we wrap up by discussing recommendations and the next steps for the project moving forward.

Since …

A Model For Spacecraft Relative Motion Using Continuous Periodic Thrust, Philip Alan Hittepole

Dissertations

A model for modifying the relative orbit of a deputy satellite with respect to a chief satellite in a near-circular orbit using continuous periodic thrust is presented. This model is built on the Lovell-Spencer relative orbital elements (ROEs). The four linear ROEs (xr, yr, ar, and Az) can be linearly modified. The two angular ROEs (Er and ) can be set to advance at a desired, constant rate. Each ROE can be modified individually but may cause intra-orbit variations in other ROEs which return to their original values at the end of a thrust cycle. A method to easily calculate …

Short Arc Initial Orbit Determination For Leo Objects And The Impact Of Observation Eelevation On Predictive Accuracy, Alexis Digregorio

Master's Theses

The expansion of space activities has led to an increase in congestion. With this increase, there has been a growing emphasis on the importance of space situational awareness. Without it, the space environment can become hazardous, with increasing threats of collision and debris generation. As the utilization of space continues to grow, effective methods for tracking objects to maintain situational awareness must also be considered. One approach to tracking objects in space involves a series of steps, including optical observations and orbit estimations using initial orbit determination methods, followed by additional observations and continuous tracking. However, a challenge with this …

Team F16: Autonomous Research Plane, Andrew Sugamele, Andrew Whitacre, Nicholas Toal, Cole Bushur

Mechanical Engineering

The autonomous research plane is a remote-controlled plane used for both in-flight data collection and to explore new manufacturing methods for Design Build Fly, an engineering club on campus. The club does not have the resources or time to implement data collection for their competition plane, so we built a plane in parallel, following similar rules to mimic the work and schedule that the club would use during their season. We first did research and analysis to determine the structure of the plane, geometry of wings, sizing of the tail, and what airfoil to choose. The manufacturing process included making …

Sizing Wind Tunnel Heater For High Enthalpy Conditions, Justin M. Slavick

Master's Theses

This paper determines the feasibility of adding a heater to an existing blowdown supersonic wind tunnel to unlock new high-enthalpy test applications, considering cost and power requirements at a variety of different states. This process includes both modeling the current range of test section properties in Cal Poly's blowdown wind tunnel and determining the new range of properties that a heat exchanger could induce. These results are verified with a computational fluid dynamics study. Additionally, sublimation and ablation properties of materials are explored to create appropriate models to study atmospheric re-entry once the heat exchanger is implemented.

It is found …

Pkt-Sin: A Secure Communication Protocol For Space Information Networks With Periodic K-Time Anonymous Authentication, Yang Yang, Wenyi Xue, Jianfei Sun, Guomin Yang, Yingjiu Li, Hwee Hwa Pang, Robert H. Deng

Research Collection School Of Computing and Information Systems

Space Information Network (SIN) enables universal Internet connectivity for any object, even in remote and extreme environments where deploying a cellular network is difficult. Access authentication is crucial for ensuring user access control in SIN and preventing unauthorized entities from gaining access to network services. However, due to the complex communication environment in SIN, including exposed links and higher signal delay, designing a secure and efficient authentication scheme presents a significant challenge. In this paper, we propose a secure communication protocol for SIN with periodic k-time anonymous authentication (named PkT-SIN) that allows satellite users to anonymously authenticate to ground stations …

Exploring The Feasibility Of The Resonance Corridor Method For Post Mission Disposal Of High-Leo Constellations, Payton G. Porter

Master's Theses

In the upcoming decade, the proliferation of high-LEO constellations is expected to exceed 20,000 objects, yet comprehensive Post Mission Disposal (PMD) strategies for these constellations are currently lacking. With the inherent challenges of efficiently deorbiting satellites from High-LEO orbits, there arises an urgent need to explore innovative approaches. Building upon insights garnered from the ReDSHIFT project and anticipating the proliferation of high-LEO constellations such as OneWeb, TeleSat, and GuoWang, this thesis delves into the potential viability of the Resonance Corridor Method for PMD. The investigation encompasses key metrics, including deorbit timelines and $\Delta v$ requirements to meet regulatory standards or …

The Pressure Distribution Of Rotating Cylinders Using An Onboard Wireless Data Acquisition System, Nathan Eller

Master's Theses

This thesis presents a novel, cost-effective method for mapping the pressure distribution on a rotating cylinder in cross flow, a phenomenon central to the Magnus effect. Utilizing commercial-off-the-shelf (COTS) micro-electromechanical system (MEMS) pressure sensors, a high-resolution data acquisition system was developed and integrated into a rotating cylinder model. Compared to traditional approaches, such as slip rings or one-off designs, this method proved significantly cheaper and faster while achieving comparable or superior resolution. The experimental setup, including a modified continuous rotation technique and adaptable model design, facilitated rapid testing across a broad range of Reynolds numbers and reduced frequencies, exceeding the …

Preliminary Analysis Of A 12u Astronomy Cubesat, Charles Van Steenwyk

Master's Theses

The explosion of exoplanet astronomy has led to thousands of new discoveries and opportunities to be explored. The ability to capture images and perform meaningful science has resulted in an abundance of follow-on missions, surveys, and fostered a community of amateur astronomers in the last ten years. This success mirrors the development of CubeSats, which have proved an immensely popular way for students of all levels to access space and collect data. Multiple CubeSats have been developed to observe and characterize single exoplanet tran- sits, showing that this class of mission is possible. However, there is currently no mission designed …

Heat Sink With Fins And Phase Change Material For Cooling Of High-Power Electronic Devices, Farooq Fakher Mahmoud

Theses

Electronics are integral to modern life, present in everything from household appliances to advanced computers. The performance and reliability of these devices are closely tied to their operating temperatures. High-power operations can lead to significant heating, necessitating effective thermal management to enhance functionality and prevent failure. This requirement drives the demand for efficient heat sinks, which dissipate the heat generated by these devices. Phase change material (PCM)-based heat sinks have become a popular passive cooling solution, increasingly replacing traditional heat sinks.

This research investigates finned PCM-based heat sinks using numerical simulations validated by existing literature and experimental data. Gallium is …

The Effect Of Atomic Oxygen On Additively Manufactured Materials, Ryan Grogan

Master's Theses

Additive manufacturing (AM) is a rapidly developing manufacturing method utilized in fields such as the aerospace industry. In-space AM is a technology of interest for the future of spaceflight, including on-orbit manufacturing. However, AM materials are subject to defects that may impact their performance in space-based applications. How these defects change the material’s reaction to the space environment, specifically atomic oxygen (AO), has only recently been explored. AO is a highly corrosive, dominant constituent in low Earth orbit that causes continuous erosion of spacecraft surfaces. The effect of AO on various AM materials is investigated in this thesis. Stainless steel, …

Developing A Lean Spacecraft Test And Evaluation Architecture For A Contested Space Domain, Stephen K. Tullino

Theses and Dissertations

The US Space Force (USSF) is currently investigating possible opportunities to improve the testing paradigm of spacecraft in order to get assets on-orbit faster, while maintaining suitable quality to meet mission needs in a contested space environment. To support this goal, USSF’s approach to test and evaluation (T&E) is centered around the concept of integrated test. In this research, the space text lexicon is defined, addressing the ambiguities on exactly what integrated test is with respect to spacecraft systems development and on-orbit mission assurance. This research considered any statistical trends in categorical discrepancies (i.e., anomalies) during prelaunch integration and test …