Natural 2d Layered Mineral Cannizzarite With Anisotropic Optical Responses,
2022
Missouri University of Science and Technology
Natural 2d Layered Mineral Cannizzarite With Anisotropic Optical Responses, Arindam Dasgupta, Xiaodong Yang, Jie Gao
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Cannizzarite is a naturally occurring mineral formed by van der Waals (vdW) stacking of alternating layers of PbS-like and Bi2S3-like two-dimensional (2D) materials. Although the PbS-type and Bi2S3-type 2D material layers are structurally isotropic individually, the forced commensuration between these two types of layers while forming the heterostructure of cannizzarite induces strong structural anisotropy. Here we demonstrate the mechanical exfoliation of natural cannizzarite mineral to obtain thin vdW heterostructures of PbS-type and Bi2S3-type atomic layers. The structural anisotropy induced anisotropic optical properties of thin cannizzarite flakes are explored through angle-resolved polarized Raman scattering, linear dichroism, and polarization-dependent anisotropic third-harmonic generation. …
Project Management And Systems Engineering Framework For Educational Cubesat Missions,
2022
California Polytechnic State University, San Luis Obispo
Project Management And Systems Engineering Framework For Educational Cubesat Missions, Bailey Garrett
Master's Theses
The rising complexity of CubeSat missions and the unique challenges faced by educational CubeSat programs lead to high rates of mission failure. Implementing project management and systems engineering practices can alleviate these challenges and improve mission success rates for educational CubeSat developers. However, existing project management and systems engineering resources are too cumbersome and often assume the student has a base-level understanding of project management and systems engineering fundamentals. A new universal project management and systems engineering framework was created and tailored specifically to the needs of an educational CubeSat mission. The framework was designed to accommodate first-time CubeSat developers, …
Effects Of Atomic Oxygen On Outgassing Of Silicone Materials,
2022
California Polytechnic State University, San Luis Obispo
Effects Of Atomic Oxygen On Outgassing Of Silicone Materials, Samuel Westrick
Master's Theses
An important consideration for spacecraft material selection is the space environment that the spacecraft will be operating in. Two features of the space environment that drive material selection are material outgassing and the presence of atomic oxygen in low Earth orbit (LEO). Materials that are considered for use in space are tested to be able to understand how they’ll outgas on orbit and how they’ll respond to interactions with atomic oxygen. However, testing to understand how atomic oxygen interaction with a material will affect how the material will outgas is rare and not standardized. This thesis used a vacuum chamber …
The Design And Development Of A Miniature Gridded Ecr Ion Thruster,
2022
Western Michigan University
The Design And Development Of A Miniature Gridded Ecr Ion Thruster, Nicholas Nuzzo
Masters Theses
Plasma propulsion, a specific subset of electric propulsion (EP), is a class of space propulsion that produces plasma by excitation of a propellant at or above its ionization energy. This ionized propellant is then accelerated by an externally applied field (magnetic and/or electric) and produces thrust. There is an increasing need for miniaturization in spacecraft technology and the use of plasma EP devices in space propulsion. These systems provide an advantage over traditional chemical propulsion solutions which are less efficient and have more mass. Miniaturization of EP devices allows missions to have more space and mass available for their payloads …
A Comparative Evaluation Of Oxidation And Combustion Phenomena In Ti-6al-4v Exposed To Earth Re-Entry And Arc-Jet Test Environments,
2022
University of Texas at El Paso
A Comparative Evaluation Of Oxidation And Combustion Phenomena In Ti-6al-4v Exposed To Earth Re-Entry And Arc-Jet Test Environments, Arlene Smith
Open Access Theses & Dissertations
The Ti-6Al-4V alloy is widely used in aerospace applications for its beneficial combination of properties. However, this alloy has high solubility for oxygen and thus a high reactivity. Recovered data contained within the Columbia artifacts suggests that this alloy underwent an accelerated degradation and combustion reaction when exposed to the high enthalpy, low-pressure surroundings experienced during reentry into Earth's atmosphere. Arc-jet testing has provided a simulated aerothermodynamic heating environment to mimic what the spacecraft endured. When the effect of thermal alteration on this alpha-beta phase alloy was investigated during previous studies, optical metallography and microhardness tests revealed inconsistencies between samples …
Artificial Neural Network For Predicting Heat Transfer Rates In Supercritical Carbon Dioxide,
2022
Embry-Riddle Aeronautical University
Artificial Neural Network For Predicting Heat Transfer Rates In Supercritical Carbon Dioxide, Vinusha Dasarla Giri Babu
Doctoral Dissertations and Master's Theses
Supercritical carbon dioxide as a working fluid in a closed Brayton cycle is proving to be more efficient than a conventional steam-based Rankine engine. Understanding the heat transfer properties of supercritical fluids is important for the design of a working engine cycle. The thermophysical properties of supercritical fluids tend to vary non-linearly near the pseudo-critical region. Traditionally, empirical correlations are used to calculate the heat transfer coefficient. It has been shown in the literature and within our own studies that these correlations provide inaccurate predictions near the pseudo-critical line, where heat transfer may be deteriorated or enhanced, resulting from strong …
A Mechanically Intelligent Hosing-Drone,
2022
University of Nevada, Las Vegas
A Mechanically Intelligent Hosing-Drone, Blake Hament
UNLV Theses, Dissertations, Professional Papers, and Capstones
This manuscript presents a ”mechanically intelligent” approach to designing a Hosing-Drone for heavy-duty pressure washing. Spraying a hose creates strong reaction forces and torques. Previously demonstrated spraying robots are over-engineered to be very massive with huge inertias. These high inertias ”wash out” the reaction from the spraying. In the proposed approach, the contributions from all observable fluid dynamics, fluid structure interactions, and aerodynamics are studied individually and for the coupled system. Experimental data is collected and fit to dynamic models. These models are used to design a smaller, lighter, more agile vehicle than has been previously demonstrated. An impedance controller …
Advanced Generalized Predictive Control And Its Application To Tiltrotor Aircraft For Stability Augmentation And Vibration Reduction,
2022
Old Dominion University
Advanced Generalized Predictive Control And Its Application To Tiltrotor Aircraft For Stability Augmentation And Vibration Reduction, Thomas Glen Ivanco
Mechanical & Aerospace Engineering Theses & Dissertations
The goals of this research were to restore generalized predictive control (GPC) capability at NASA and within the community, to better understand GPC and its performance relative to other options, and to improve upon the capability of GPC. Unique to this research is the comparison of GPC with other control options including PID controllers, optimal control theory, and other versions of the similar AutoRegressive moving average model with eXogenous inputs (ARX) models. Similar to GPC, ARX models use an experimentally acquired system identification to characterize the input/output relationship between controls and response measurements. Because this relationship is determined from acquired …
Analysis Of Propeller Designs Focusing On Lowering Sound Pressure Level Through Reduced Tip Loading,
2022
Air Force Institute of Technology
Analysis Of Propeller Designs Focusing On Lowering Sound Pressure Level Through Reduced Tip Loading, Luca A. Zeitvogel
Theses and Dissertations
This research focused on potential design optimizations for small propellers. Designs sought to reduce noise generated without sacrificing efficiency by “unloading” the propeller tip by reducing angle of attack near the tip. To see if nearfield performance improvements translated to a reduction in farfield sound pressure level, farfield experimental acoustic testing was performed on propellers that had been measured experimentally in the nearfield. The farfield results provided limited insight due to an equipment malfunction during testing. However, a large data set was obtained, which provides opportunities for future analyses. A computational simulation sought to recreate some of the nearfield experiments …
Compact Electrospray Propulsion Systems For Small Form-Factor Satellites: An Orbital Performance Survey & Platform Design,
2022
University of Texas at El Paso
Compact Electrospray Propulsion Systems For Small Form-Factor Satellites: An Orbital Performance Survey & Platform Design, Alberto Meza
Open Access Theses & Dissertations
Over the past decades, small form-factor satellites such as CubeSats have remained as one of the most accessible platforms to reach space for universities, research institutions, private and governmental entities to perform a wide range of missions. This paper presents a survey into the design and implementation of an electrospray rail thruster, to be integrated to the CubeSat platform. The design investigated features propellant tanks for each individual thruster embedded inside the rail of a standard 1U CubeSat. The capabilities of utilizing the electrospray thruster as an attitude & determination control system was also investigated in which, a pointing accuracy …
Cryogenic Flow Boiling Heat Transfer On Additively Manufactured Liquid Rocket Engine Cooling Channels,
2022
University of Texas at El Paso
Cryogenic Flow Boiling Heat Transfer On Additively Manufactured Liquid Rocket Engine Cooling Channels, Debra Jazmin Ortega
Open Access Theses & Dissertations
The enhancement of flow boiling heat transfer is critical because it can solve thermal management issues seen across all engineering and manufacturing applications. Even though advancements are being made, more studies are needed to understand the behavior of forced convective boiling further.Currently, there are four major issues in the field of regenerative cooling of liquid rocket engines. 1. The cooling channels are typically manufactured using conventional machining, while aerospace industries are currently exploring the additive manufacturing approach. 2. The experimental critical heat flux values for cryogenic fluids are either lower or very close to the model predictions; however, the effect …
2022 Summer-Fall Graduate Recognition Program,
2022
The University of Alabama in Huntsville
2022 Summer-Fall Graduate Recognition Program, Propulsion Research Center, Robert Frederick
PRC Graduate Recognition
This program includes the graduate recognition program for summer and fall 2022. Includes photographs, upcoming events, recent publications, and student profiles.
Stress-Based Topology Optimization Of Pi Preform-Bonded Composite Laminate Structure,
2022
Florida Institute of Technology
Stress-Based Topology Optimization Of Pi Preform-Bonded Composite Laminate Structure, Iwan Broodryk
Theses and Dissertations
The purpose of this work is to explore the stress-based topology optimization of structure that utilizes laminated composites and 3D woven Pi preform joints. Simple geometry, loading, and boundary conditions are considered. At a finite element level, an aggregate stress ratio is developed for Pi joint and acreage laminate elements. A basic descent method of moving asymptotes (BDMMA) algorithm is created to solve all optimization problems. Topology results for two different stress-based formulations and a compliance minimization problem are compared, followed by an in-depth analysis at a Pi joint and laminate level.
Analysis Of Proposed Active Radiation Shielding Design Concept For Spacecraft,
2022
Florida Institute of Technology
Analysis Of Proposed Active Radiation Shielding Design Concept For Spacecraft, Claire Mechmann
Theses and Dissertations
A need exists to protect the crew of interplanetary spacecraft from lethal doses of Galactic Cosmic Radiation (GCR) and Solar Energetic Particles (SEPs). As plans progress to send humans beyond lower Earth orbit (LEO) and outside of Earth’s protective magnetosphere, agencies involved in this endeavor find themselves confronted with the obstacle of shielding the crew from this harmful radiation. A proposed active shielding concept design has been suggested, utilizing charged dielectric capacitors to deflect incoming charged particles. This analysis will examine the feasibility of the proposed design and offer potential materials useful for application. The results should prove informative for …
Accelerated Aging Of Adhesively Bonded Composite Joints For Use In Material Screening And Selection During Development: A Review And Case Study,
2022
Florida Institute of Technology
Accelerated Aging Of Adhesively Bonded Composite Joints For Use In Material Screening And Selection During Development: A Review And Case Study, Marie Danielle Flanigan
Theses and Dissertations
Adhesively bonded structures are used in many high-tech industries such as aerospace, automotive, and defense. The application of these joints using composite adherends has increased in recent years because of improved strength-to-weight ratio, design flexibility, and lower concern for corrosion. Quality acceptance of these structures largely depends on reliability and durability which includes influence of environmental service conditions on long-term behavior. Characterization of long-term behavior presents a difficult challenge to those involved in material selection and design due to the long service life of the joint compared to the development time available and complexity of the degradation mechanisms. Therefore, different …
Comparison Of Stability And Control Characteristics Of The Pipistrel Virus Sw And Pipistrel Velis Electro,
2022
Florida Institute of Technology
Comparison Of Stability And Control Characteristics Of The Pipistrel Virus Sw And Pipistrel Velis Electro, Sean Gregory Gunther
Theses and Dissertations
This document finds the stability and control affects of electric powerplant conversion on a pre-existing internal combustion powered Pipistrel Virus SW through comparison with the Pipistrel Velis Electro. Testing included analysis of both static and dynamic stability on the longitudinal and lateral-directional axes of the airplane. Due to the light sport airplane being used in testing, some of the intedended tests were unable to be performed, however, conclusions were still capable of being made. The primary conclusion is that electric conversion of an airframe has no significant negative consequences, with the airplane still exhibiting positive stability on all three axes. …
Piper Pa-28-181 Archer Iii Tail #931ec Flight Test Stability, Control And Performance,
2022
Florida Institute of Technology
Piper Pa-28-181 Archer Iii Tail #931ec Flight Test Stability, Control And Performance, Steven Allan Sutton
Theses and Dissertations
The following flight test was conducted as part of the culmination requirement for the Master of Science, Flight Test Engineer degree program from Florida Institute of Technology. The flight was conducted to gather data and produce a flight test report on the data gathered. The flight test plan consisted of a series of both Stability and Handling test point as well as basic aircraft performance points. The testing was planned to be accomplished over a single flight, for reasons discussed later in this report. The flight departed on the morning of 26 September, 2022 out of Bob Sikes Airport, KCEW, …
Developmental Evaluation Of The B-1b Aircraft,
2022
Florida Institute of Technology
Developmental Evaluation Of The B-1b Aircraft, Jonathon Malycke
Theses and Dissertations
The purpose of this test was to perform a Developmental Phase IIA evaluation of the B-1B Lancer for the land-based, long-range, all-weather ground attack mission. One two-hour ground evaluation, one simulator and one flight totaling 7.5 hours was conducted under daylight, visual meteorological conditions from Dyess Air Force Base (AFB) in Abilene, Texas (337th Test and Evaluation Squadron). All test objectives were completed except the low altitude flight evaluation, landing pattern operations, and AFCS operations due to weather, maintenance and time constraints. The test aircraft was representative of a production B-1B aircraft and included a Sniper Targeting Pod and a …
Carbon Fibers From Bio-Based Precursors Derived From Renewable Sources,
2022
Clemson University
Carbon Fibers From Bio-Based Precursors Derived From Renewable Sources, Sagar Kanhere
All Dissertations
Carbon fibers have the highest strength and modulus among all known fibers and are used as reinforcements in high-performance composites [1]. Carbon fibers also have a very low density relative to metals. Therefore, carbon fibers possess ultrahigh specific strength and modulus, which make them desirable for high-performance light-weight composites. A vast majority of commercial carbon fibers are produced from PAN precursors that are expensive, which limits the use of PAN-derived carbon fibers to aerospace applications (e.g., airplanes). However, for costsensitive applications, there is a need for low-cost, moderate performance carbon fibers. Lignin is a low-cost by-product of pulping and biorefining …
Dynamic Analysis, Characterization, And Design Of Rigid-Flex Pcb Robotics,
2022
Clemson University
Dynamic Analysis, Characterization, And Design Of Rigid-Flex Pcb Robotics, John Bell
All Dissertations
The era of space exploration is driven by and fuels large advances in technological progress.
Over the last decade, engineering practices for spacecraft, space structures, robotics, software and
hardware, manufacturing techniques, and the implementation of new and novel materials has been
revolutionized. Space exploration pushes the envelope in terms of technological capabilities and
robotic systems (rovers) become lighter, smaller, and more capable of sustaining damage. This
dissertation aids in the advancement of design knowledge for a class of rovers characterized by
their chassis architecture: rigid-flex printed circuit board (PCB) robotics. These rovers leverage
the printed circuit cards as the structural …
