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 …
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 …
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 …
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 …
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 …
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 …
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.
Performance Variability In Solid Rocket Motors,
2022
University of Alabama in Huntsville
Performance Variability In Solid Rocket Motors, Manvith Amara
Honors Capstone Projects and Theses
No abstract provided.
The Development And Characterization Of Piezoelectric- Magnetostrictive Smart Self-Sensing Composites,
2022
University of Texas at Arlington
The Development And Characterization Of Piezoelectric- Magnetostrictive Smart Self-Sensing Composites, George Relebohile Qhonosheane
Mechanical and Aerospace Engineering Dissertations - Archive
The composites industry is expanding due to the growing global demand for high-performance materials. How do you ensure the production of composites is as smooth and effective as possible while maintaining the high quality of the material? The key issues in composites include crack occurrence, sticking to molds in the production process, and durability differences during their operation. However, monitoring such cases can be challenging. The industry is in need of a smart solution to be able to obtain accurate data from the raw material. This work focuses on the development of smart composite materials. The word composite comes from …
Assessment Of Contaminant Flowpaths In Airside Economization And Analysis Of Thermal Performance At Tank And Server Level For Single-Phase Immersion Cooled Data Centers,
2022
University of Texas at Arlington
Assessment Of Contaminant Flowpaths In Airside Economization And Analysis Of Thermal Performance At Tank And Server Level For Single-Phase Immersion Cooled Data Centers, Satyam Saini
Mechanical and Aerospace Engineering Dissertations - Archive
The last two decades of 2000 have seen an explosion of utilization and reliance on digital technologies and platforms. During this time, electronic devices have undergone intense miniaturization and a corresponding rise in power densities. In parallel to these developments, data center proliferation has been driven by the increasing utility of revolutionary technologies such as Machine Learning, Artificial Intelligence, e-commerce and, the Internet of Things. Data centers, thus, have become the core of the modern digital age. The primary bottleneck, however, due to extensive device miniaturization and data center proliferation has always been thermal management. Many of the aforementioned technologies …
Development Of An Electro-Pneumatic Servo Clutch And Industry-Level Controller,
2022
University of Texas at Arlington
Development Of An Electro-Pneumatic Servo Clutch And Industry-Level Controller, Timothy Stevens
Mechanical and Aerospace Engineering Theses - Archive
This thesis covers the simulation and development of an electro-pneumatic servo clutch used on an FSAE racecar. This project utilizes a sophisticated simulation and various techniques to increase performance such as utilizing pulse-width and pulse-frequency modulation and the use of a 36V supply with constant current limiting to drive the solenoids. The clutch is actuated using a pneumatic cylinder with the internal pressure modulated using commercially available CNG fuel injectors. This thesis also describes the development of the electronic controller designed using analog circuits, as well as the integration of digital circuits to control operations such as launch control and …
Computational Reliability Analysis Of Blind Micro-Via With 3d And Axisymmetric Multi-Layer Pcb,
2022
University of Texas at Arlington
Computational Reliability Analysis Of Blind Micro-Via With 3d And Axisymmetric Multi-Layer Pcb, Jayendra Bazaru
Mechanical and Aerospace Engineering Theses - Archive
Micro-via are components that are used to form connections from one layer to another in most Multilayered Printed Circuit Boards (PCBs). The failure of Micro-via has always been a concern of the electronic industry. The failures are exaggerated during the reflow process due to the high thermal loading. Electronic components have become ubiquitous in our society. It is important to take some measures to reduce (or) eliminate the failures at interconnects in the Printed Circuit Board to obtain highly reliable Input/Output (I/O). This work is based on a hypothetical belief that the possible cause of failure is an insufficient or …
Autonomous Aerial Vehicles Distributed Control And Interactive Games,
2022
University of Texas at Arlington
Autonomous Aerial Vehicles Distributed Control And Interactive Games, Yusuf Kartal
Mechanical and Aerospace Engineering Dissertations - Archive
As the number of quadrotors and other Unmanned Aerial Vehicles (UAVs) increases in industrial and urban areas, the development of reliable engineering methods to control their behavior as they interact with each other becomes of central interest in control research. With the increase in demand for UAVs to work together, several real-life challenges need to be addressed that include the implementation, test, and validation of the control algorithms in flight test experiments. On the one hand, the interests of UAVs may be in harmony to perform certain tasks such as transportation, surveillance and reconnaissance. On the other hand, the interests …
Carbon Fiber Coil Spring Characterization And Manufacturing,
2022
University of Nevada, Las Vegas
Carbon Fiber Coil Spring Characterization And Manufacturing, Cooper Madrazo
UNLV Theses, Dissertations, Professional Papers, and Capstones
Helical coil springs are used in many mechanical design applications including industrial machines, devices, and vehicle suspension systems. It is desirable to minimize the weight of vehicle suspension systems as this can improve performance and handling. Most vehicle suspension coil springs are made from solid steel alloys or other metallic materials. Significant weight savings could be achieved if the metallic material were replaced by high performance fiber reinforced polymer composites. However, the coil spring geometry is a difficult manufacturing challenge for composite materials. The goal of this thesis was to investigate efficient and low-cost manufacturing methods to produce light-weight polymer …
Fuel Injector Design Of A Hypersonic Jet Engine Using Computational Fluid Dynamics,
2022
University of Nevada, Las Vegas
Fuel Injector Design Of A Hypersonic Jet Engine Using Computational Fluid Dynamics, Melissa Rose Mercado
UNLV Theses, Dissertations, Professional Papers, and Capstones
The development of hypersonic airbreathing engines, such as a supersonic combustion ramjet, or scramjet, are implemented for flight Mach numbers over 5 where combustion must occur in supersonic conditions. The advancement of scramjet propulsion has led to favored usage over rocket propulsion systems for in atmosphere applications due to their lighter weight, higher specific impulse, and greater maneuverability [1]. The combustor section of a scramjet engine houses the fuel injectors. Fuel is injected into the supersonic flow with the main objective of achieving rapid and thorough fuel-air mixing because the residence time in the combustion chamber has a timescale of …
Viability Of Energy And Fuel Sources For Interstellar Travel; Design And Feasibility Of The Construction Of Manned Interstellar Space Shuttles,
2022
University of Nevada, Las Vegas
Viability Of Energy And Fuel Sources For Interstellar Travel; Design And Feasibility Of The Construction Of Manned Interstellar Space Shuttles, Lukas Mittelman
UNLV Theses, Dissertations, Professional Papers, and Capstones
The importance of proving the viability of interstellar transport and addressing its potential hazards and pitfalls is immense. If we do not look toward the future and examine what could be waiting for us, we are doing our children, our children’s children, and so on, a disservice. Here we must attempt to lay the groundwork for our future scientists, engineers, and adventurers. Asking and answering questions like, which propulsion and energy systems must we incorporate to send us through the cosmos? Will we utilize technologies known today, such as fossil fuel rockets, fission or fusion rockets, and antimatter drives (pion …
