Uv Space Imager Enclosure Coating,
2022
California Polytechnic State University, San Luis Obispo
Uv Space Imager Enclosure Coating, David Silva Cortez, Victor Alexander Rempel Dekhtyar, Maria L. Muñoz
Mechanical Engineering
The goal of this project is to reduce the amount of stray light entering an ultraviolet (UV) imager through absorption. This report outlines the use of ZnO nanoparticles mixed in an epoxy matrix for use in a CubeSat enclosure. Through testing, our team verified that the ZnO and epoxy coating experienced a peak absorption between 360-370 nm. The epoxy mixture with the .75% by weight ZnO nanoparticles absorbed up to 99.9 % of UV light at its peak. The effect on material properties, such as Young’s modulus and ultimate tensile strength, was also tested. Tensile tests demonstrated that adding ZnO …
Method And Simulation Of On-Orbit Sub-Microthrust Evaluation,
2022
California Polytechnic State University, San Luis Obispo
Method And Simulation Of On-Orbit Sub-Microthrust Evaluation, Jonathan Hood
Master's Theses
With the advent of smaller satellites, along with the need for less than 0.1 μN precision attitude control for interferometry and imaging missions, finer micro- to sub-micro- thrusters have become an area of high interest. As thrusters are developed and ground-tested, it is necessary to evaluate their thrust performance on-orbit. On-orbit measurements offer actual thrust performance in mission conditions, free from ground facility vibrations and miniaturization restraints, and allow a thruster system to achieve a NASA Technology Readiness Level (TRL) of 7-8. A review is conducted of existing and proposed ground and on-orbit thrust measurement techniques. Experimental gaps and complementary …
Low-Cost Uav Swarm For Real-Time Object Detection Applications,
2022
California Polytechnic State University, San Luis Obispo
Low-Cost Uav Swarm For Real-Time Object Detection Applications, Joel Valdovinos Miranda
Master's Theses
With unmanned aerial vehicles (UAVs), also known as drones, becoming readily available and affordable, applications for these devices have grown immensely. One type of application is the use of drones to fly over large areas and detect desired entities. For example, a swarm of drones could detect marine creatures near the surface of the ocean and provide users the location and type of animal found. However, even with the reduction in cost of drone technology, such applications result costly due to the use of custom hardware with built-in advanced capabilities. Therefore, the focus of this thesis is to compile an …
Aerodynamics And Aeroacoustics Optimization Of Vehicle’S Side Mirror Base And Exhaust Pipe,
2022
United Arab Emirates University
Aerodynamics And Aeroacoustics Optimization Of Vehicle’S Side Mirror Base And Exhaust Pipe, Moath Nayef Mohamed Zaareer
Theses
This thesis is concerned with studying two different vehicle parts in terms of aerodynamics and aeroacoustics. Two main factors determine the efficiency and luxury of the vehicle, the low aerodynamic forces and low noise emission. The aerodynamic drag coefficient is concerned with how easy a vehicle can travel through the air; the lower the value, the less fuel is needed to move the vehicle forward and less air resistance the vehicle faces. The aerodynamic lift coefficient is related to vehicle ground stability, and the more negative the value is, the higher the vehicle's stability. Moreover, the aeroacoustics is concerned with …
Static Testing Of Hybrid Rocket Engine Using Biomass Waste,
2022
United Arab Emirates University
Static Testing Of Hybrid Rocket Engine Using Biomass Waste, Saleh Mohammed Musaed Badi
Theses
This work investigates experimentally for the first time the performance of two solid biomass wastes as propellants for a Hybrid Rocket Motor based on the combustion and propulsion parameters such as combustion chamber pressure, thrust force, chamber temperature, combustion characteristics, and flame length generated. The main objective of this study is to examine the performance of the proposed biomass fuels (Date stone powder and Jojoba waste powder) in comparison with typical hydrocarbon fuels. To make an accurate comparison, Paraffin Wax-based propellant was used in this study as a reference fuel to compare with biomass performance using the same testing facility …
Tini-Based Bi-Metallic Shape-Memory Alloy By Laser-Directed Energy Deposition,
2022
Missouri University of Science and Technology
Tini-Based Bi-Metallic Shape-Memory Alloy By Laser-Directed Energy Deposition, Yitao Chen, Cesar Ortiz Rios, Braden Mclain, Joseph William Newkirk, Frank W. Liou
Materials Science and Engineering Faculty Research & Creative Works
In this study, laser-directed energy deposition was applied to build a Ti-rich ternary Ti–Ni–Cu shape-memory alloy onto a TiNi shape-memory alloy substrate to realize the joining of the multifunctional bi-metallic shape-memory alloy structure. The cost-effective Ti, Ni, and Cu elemental powder blend was used for raw materials. Various material characterization approaches were applied to reveal different material properties in two sections. The as-fabricated Ti–Ni–Cu alloy microstructure has the TiNi phase as the matrix with Ti2Ni secondary precipitates. The hardness shows no high values indicating that the major phase is not hard intermetallic. A bonding strength of 569.1 MPa was obtained …
Performance Study Of Post-Processed Additively Manufactured Low Thrust Nozzles,
2022
Air Force Institute of Technology
Performance Study Of Post-Processed Additively Manufactured Low Thrust Nozzles, Tyler W. Gerhold
Theses and Dissertations
This research explores metal post-processing techniques to effectively reduce the large anomalous protrusions found in small additively manufactured low thrust rocket nozzles. Research has found that nozzles of this kind can experience losses in thrust of over 40%. Analytic theory of adiabatic nozzle flow with viscous losses for additively manufactured nozzles does not align with what has been found when tested experimentally. Compressible flow losses, such as shock wave formation inside the nozzle diverging cone, are likely the leading causes of such loss. Reduction in nozzle irregularities can likely yield results seen in analytic theory with similar performance to traditional …
Dual-Band Selective Circular Dichroism In Mid-Infrared Chiral Metasurfaces,
2022
Missouri University of Science and Technology
Dual-Band Selective Circular Dichroism In Mid-Infrared Chiral Metasurfaces, Haotian Tang, Daniel Rosenmann, David A. Czaplewski, Xiaodong Yang, Jie Gao
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Most chiral metamaterials and meta surfaces are designed to operate in a single wavelength band and with a certain circular dichroism (CD) value. Here, mid-infrared chiral meta surface absorbers with selective CD in dual-wavelength bands are designed and demonstrated. The dual-band CD selectivity and tunability in the chiral meta surface absorbers are enabled by the unique design of a unit cell with two coupled rectangular bars. It is shown that the sign of CD in each wavelength band can be independently controlled and flipped by simply adjusting the geometric parameters, the width and the length, of the vertical rectangular bars. …
Natural Layered Mercury Antimony Sulfosalt Livingstonite With Anisotropic Optical Properties,
2022
Missouri University of Science and Technology
Natural Layered Mercury Antimony Sulfosalt Livingstonite With Anisotropic Optical Properties, Ravi P.N. Tripathi, Jie Gao, Xiaodong Yang
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Naturally occurring layered mineral livingstonite is identified as a new type of van der Waals (vdW) heterostructure based 2D material, consisting of two commensurately modulated alternating layers of HgSb2S4 and Sb2S4. The heterostructures of livingstonite crystal are prepared as thin flakes via mechanical exfoliation method. The prepared livingstonite crystals are further investigated in the context of vibrational, linear, and nonlinear optical properties, including anisotropic Raman scattering, wavelength-dependent linear dichroism (LD) transition effect, birefringence, and anisotropic third-harmonic generation (THG). Owing to the monoclinic crystal structure, livingstonite crystals exhibit strong anisotropic vibrational and optical responses. In contrast to conventional vdW heterostructures, the …
Flow And Heat Transfer In Swirl Tubes — A Review,
2022
Institute of Aerospace Thermodynamics, University of Stuttgart
Flow And Heat Transfer In Swirl Tubes — A Review, Florian Seibold, Phillip M. Ligrani, Bernhard Weigand
PRC-Affiliated Research
The development of modern gas turbines for aircraft propulsion and power generation demands ever-increasing efficiency, which can be achieved by rising the turbine inlet temperature. Therefore, turbine components and especially the leading edge of turbine blades are exposed to particular high thermal loads with temperatures that are well above the melting point of the material. As a result, efficient cooling techniques are essential. Swirling flows in cyclone cooling systems are a promising technique for internal turbine blade leading edge cooling since they promise high heat transfer rates in combination with relatively uniform heat transfer distributions. The current paper presents a …
Aerodynamics And Turbulent Wake-Flow Characteristics Of Owls During Flapping Flight,
2022
Coastal Carolina University
Aerodynamics And Turbulent Wake-Flow Characteristics Of Owls During Flapping Flight, Krishnamoorthy Krishnan
Electronic Theses and Dissertations
Owls exhibit unique flight capabilities in the low Reynolds number flow regime which is prone to complex viscous flow phenomena. They possess unique feather features and flexible wing structures which are postulated to help them fly nearly silently and stably at low speeds in a complex flow setting. Understanding the aerodynamics of owls could pave the way to enhance the future designs of small flying vehicles. Though it has been a focus of research over multiple decades, no conclusive agreement has been attained on the aerodynamic mechanisms associated with owl flight. Particularly, the aerodynamics of flapping owl flight is severely …
Updates And Improvements To The Satellite Drag Coefficient Response Surface Modeling Toolkit,
2022
Missouri University of Science and Technology
Updates And Improvements To The Satellite Drag Coefficient Response Surface Modeling Toolkit, Phillip Logan Sheridan, Smriti Nandan Paul, Guillermo Avendaño-Franco, Piyush M. Mehta
Mechanical and Aerospace Engineering Faculty Research & Creative Works
For satellites in the Low Earth Orbit (LEO) region, the drag coefficient is a primary source of uncertainty for orbit determination and prediction. Researchers at the Los Alamos National Laboratory (LANL) have created the so-called Response Surface Modeling (RSM) toolkit to provide the community with a resource for simulating and modeling satellite drag coefficients for satellites with complex geometries (modeled using triangulated facets) in the free molecular flow (FMF) regime. The toolkit fits an interpolation surface using non-parametric Gaussian Process Regression (GPR) over drag coefficient data computed using the numerical Test Particle Monte Carlo (TPMC) method. The fitted response surface …
Thermal Management Using Liquid-Vapor Phase Change In Nanochannels,
2022
Syracuse University
Thermal Management Using Liquid-Vapor Phase Change In Nanochannels, Sajag Poudel
Dissertations - ALL
Superior wettability of porous medium marks their potential to be used in the field of thermal management employing phase-change heat transfer. Comprehending the phenomena of wicking and liquid-vapor phase-change in micro/nano structured surfaces are key aspects towards advancing heat transfer solutions. In this work, fundamental understanding of droplet wicking, thin-film evaporation, and their subsequent application of heat-flux removal for cooling technology is first reported. The latter part of the dissertation is related to the disjoining pressure driven flow of nanoscale liquid film and liquid-vapor phase change in nano confinement. First, experimental and numerical investigation of droplet wicking in ∼728 nm …
Artificial Intelligence, Controls, And Sensor Fusion For Optimization And Modeling Of Space Missions And Particle Accelerators,
2022
University of New Mexico
Artificial Intelligence, Controls, And Sensor Fusion For Optimization And Modeling Of Space Missions And Particle Accelerators, Reza Pirayeshshirazinezhad
Mechanical Engineering ETDs
This PhD dissertation is devoted to developing artificial intelligence (AI) applications for space missions and particle accelerators considering constraints on the computational resources. The space mission studied in this research, the Virtual Telescope for X-ray Observations (VTXO), is the mission exploiting 2 6U-CubeSats operating in a precision formation. The goal of the VTXO project is to develop a space-based, X-ray imaging telescope with high angular resolution precision. VTXO space mission is designed and the mission is optimized to increase the performance of the mission. Trajectory optimization with AI, hybrid control, control algorithms, and high performance computing are all used to …
Optical Microresonator-Based Flow-Speed Sensor,
2022
Southern Methodist University
Optical Microresonator-Based Flow-Speed Sensor, Elie Ramon Salameh
Mechanical Engineering Research Theses and Dissertations
Optical sensors have become more prominent in atmospheric measurement systems, with LiDAR instruments deployed on a variety of earth-bound, air-borne, and space-based platforms. In recent years, the interest in the human exploration of Mars has created a substantial push towards reliable and compact sensing elements for Mars exploration missions, particularly during a spacecraft’s entry, descent, and landing stages. Real-time sensors able to reliably measure the craft’s speed relative to the surrounding atmosphere during these stages are thus of great interest. In this dissertation, a proof-of-concept for an optical microfabricated sensor, which leverages the whispering-gallery-mode (WGM) and Doppler shift principles, is …
Direct Simulation And Reduced-Order Modeling Of Premixed Flame Response To Acoustic Modulation,
2022
Mississippi State University
Direct Simulation And Reduced-Order Modeling Of Premixed Flame Response To Acoustic Modulation, Zheng Qiao
Theses and Dissertations
This dissertation introduces a general, predictive and cost-efficient reduced-order modeling (ROM) technique for characterization of flame response under acoustic modulation. The model is built upon the kinematic flame model–G-equation to describe the flame topology and dynamics, and the novelties of the ROM lie in i) a procedure to create the compatible base flow that can reproduce the correct flame geometry and ii) the use of a physically-consistent acoustic modulation field for the characterization of flame response. This ROM addresses the significant limitations of the classical kinematic model, which is only applicable to simple flame configurations and relies on ad-hoc models …
Structural Sizing Of Post-Buckled Thermally Stressed Stiffened Panels,
2022
Mississippi State University
Structural Sizing Of Post-Buckled Thermally Stressed Stiffened Panels, Walid Arsalane
Theses and Dissertations
Design of thermoelastic structures can be highly counterintuitive due to design-dependent loading and impact of geometric nonlinearity on the structural response. Thermal loading generates in-plane stresses in a restrained panel, but the presence of geometric nonlinearity creates an extension-bending coupling that results in considerable transverse displacement and variation in stiffness characteristics, and these affects are enhanced in post-bucking regimes. Herein a methodology for structural sizing of thermally stressed post-buckled stiffened panels is proposed and applied for optimization of the blade and hat stiffeners using a gradient-based optimizer. The stiffened panels are subjected to uniform thermal loading and optimized for minimum …
Application Of The Formal Design Of Experiments To Deformed Airfoil Testing,
2022
University of Mississippi
Application Of The Formal Design Of Experiments To Deformed Airfoil Testing, Alex Ligman
Honors Theses
Traditionally, one factor at a time (OFAT) testing is used to accomplish wind tunnel
experimentation. OFAT testing is a process whereby one of the defined factors in the experiment is changed while all of the other factors are held constant. Afterwards, a new factor is chosen as the one to be manipulated, and the process is then repeated until all factors have been run through. Due to the possible cost-intensive and time-consuming nature of wind tunnel testing, formal design of experiments (DOE) has begun to be applied to wind tunnel experiments. In doing so, unique analyses can be made that …
Optimization Of Orbital Trajectories Using Neuroevolution Of Augmenting Topologies,
2022
University of Connecticut
Optimization Of Orbital Trajectories Using Neuroevolution Of Augmenting Topologies, Nathan Wetherell
University Scholar Projects
This project aims to determine the feasibility of using NeuroEvolution of Augmenting Topologies (NEAT), an advanced neural network evolution scheme, to optimize orbital transfer trajectories. More specifically, this project compares a genetically evolved neural network to a standard Hohmann transfer between Earth and Mars. To test these two methods, an N-body simulation environment was created to accurately determine the result of gravitational interactions on a theoretical spacecraft when combined with planned engine burns. Once created, this simulation environment was used to train the neural networks created using the NEAT Python module. A genetic algorithm was used to modify the topology …
Using An Ultrasonic Technique To Determine Burning Rate Law,
2022
University of Alabama in Huntsville
Using An Ultrasonic Technique To Determine Burning Rate Law, Brennan Hatton Haralson
Honors Capstone Projects and Theses
No abstract provided.
