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Articles 2761 - 2790 of 11101
Full-Text Articles in Aerospace Engineering
Enhancing Situational Awareness For Rotorcraft Pilots Using Virtual And Augmented Reality, Ardit Pranvoku
Enhancing Situational Awareness For Rotorcraft Pilots Using Virtual And Augmented Reality, Ardit Pranvoku
Theses and Dissertations
Rotorcraft pilots often face the challenge of processing a multitude of data, integrating it with prior experience and making informed decisions in complex, rapidly changing multisensory environments. Virtual Reality (VR), and more recently Augmented Reality (AR) technologies have been applied for providing users with immersive, interactive and navigable experiences. The research work described in this thesis demonstrates that VR/AR are particularly effective in providing real-time information without detracting from the pilot's mission in both civilian and military engagements. The immersion of the pilot inside of the VR model provides enhanced realism. Interaction with the VR environment allows pilots to practice …
Utilizing Uas To Support Wildlife Hazard Management Efforts By Airport Operators, Flavio A. C. Mendonca, Ryan Wallace
Utilizing Uas To Support Wildlife Hazard Management Efforts By Airport Operators, Flavio A. C. Mendonca, Ryan Wallace
Publications
The FAA requires airports operating under the Code of Federal Regulations Part 139 to conduct a wildlife hazard assessment (WHA) when some wildlife-strike events have occurred at or near the airport. The WHA should be conducted by a Qualified Airport Wildlife Biologist (QAWB) and must contain several elements, including the identification of the wildlife species observed and their numbers; local movements; daily and seasonal occurrences; and the identification and location of features on and near the airport that could attract wildlife. Habitats and land-use practices at and around the airport are key factors affecting wildlife species and the size of …
Lupa: An Excursion Vehicle For The Moons Of Mars, Shannon Kavanagh, Bo Lewis, Alex Odinamba, Joshua Mulhern
Lupa: An Excursion Vehicle For The Moons Of Mars, Shannon Kavanagh, Bo Lewis, Alex Odinamba, Joshua Mulhern
Senior Design Project For Engineers
Our team has designed a spacecraft and mission for exploring the moons of Mars. The Lithological and Ultraviolet Photometry Assessment (LUPA) excursion vehicle is capable of crew habitation, autonomous rendezvous, and in-vacuum sample collection all in support of a parallel Mars surface mission to be carried out in the year 2040. Our project's key focus areas revolve around orbital mechanics, space vehicle propulsion analysis, scientific exploration, and the management of various interconnected spacecraft subsystems.
Project Scrappie (Clear Constellation), Jacob Bertram, Jacob Britt, Bill Ngo, Mike Diesing
Project Scrappie (Clear Constellation), Jacob Bertram, Jacob Britt, Bill Ngo, Mike Diesing
Senior Design Project For Engineers
Clear Constellation™ is a nationwide competition hosted by Rubicon® to combat the growing problem of space debris in Low Earth Orbit. Project Scrappie is our team’s solution to this problem. Scrappie is an autonomous apparatus will make use of Whipple shield technology to collide with debris at high velocities and effectively destroy the debris throughout selected orbital paths.
Stress Intensity Factor - Simple Solution For A Complex Problem, Hamid A. Ghassri, Alberto Mello
Stress Intensity Factor - Simple Solution For A Complex Problem, Hamid A. Ghassri, Alberto Mello
Beyond: Undergraduate Research Journal
This research explores the modeling of a cracked structure using a linear elastic finite element method (FEM) analysis with the objective of determining the stress intensity factor (SIF) for complex geometries. The analysis uses a mapping of the stress concentration area ahead of the crack tip to asymptotically determine the SIF. For model calibration, Irwin’s approximation method was used in two known crack case solutions subjected to a uniform tensile loading (Mode I – Opening) with fixed geometric dimensions. With focus on aircraft airworthiness application, two more complex geometries with irregular stress distributions were analyzed and the results were extracted …
A Numerical Study Of Water Entry Problems Based On Overset Meshes, Yanni Chang
A Numerical Study Of Water Entry Problems Based On Overset Meshes, Yanni Chang
Mechanical and Aerospace Engineering Dissertations - Archive
A series of numerical experiments carried out on the water entry of circular cylinders are presented in this study. A cylinder was entering into the water with a prescribed inclined angle and velocity. The interface between water and air is tracked by the Piecewise Linear Interface Calculation (PLIC) schemes in conjunction with the Volume of Fluid (VOF) method. PLIC schemes have been extensively employed in the VOF method for interface capturing in numerical simulations of multiphase flows. Dynamic overset meshes, which have been widely used for problems with relative motions and complex geometric shapes, are applied to handle the moving …
Characterization And Enhancement Of Fatigue And Fracture Properties In Thermoplastic Fff Parts Using In-Situ Annealing, Manjarik Mrinal
Characterization And Enhancement Of Fatigue And Fracture Properties In Thermoplastic Fff Parts Using In-Situ Annealing, Manjarik Mrinal
Mechanical and Aerospace Engineering Dissertations - Archive
Fused filament fabrication (FFF) show high anisotropy and reduced mechanical properties as compared to conventional manufacturing techniques. This happens due to the poor interlaminar bonding between the layers, as a result of premature halt of bond healing process. Previous research works show multiple approaches to improve the bond quality to enhance the mechanical properties of FFF parts, however these are complex and expensive techniques. In this work a novel print head assembly is presented to offer a simple and effective solution by applying a thermal field to the part as it is being printed to preheat the previously deposited layer, …
Internal Pressure Response Of A Human Head Surrogate Model Subject To Variable Impact Loading With Finite Element Analysis, Aaron Ronald Jackson
Internal Pressure Response Of A Human Head Surrogate Model Subject To Variable Impact Loading With Finite Element Analysis, Aaron Ronald Jackson
Mechanical and Aerospace Engineering Theses - Archive
Traumatic brain injury (TBI) from blunt impacts to the head is a major cause of brain disease and dysfunction for thousands of people every year. Each year in the United States approximately 1 million TBI cases occur causing as many as 56,000 deaths and leaving nearly 90,000 individuals with long-term disabilities. Damage resulting from a TBI occurs on a multiscale level including the macroscopic, tissue, and neuron length scale. This research focuses on correlating the macroscopic blunt impact conditions to the internal pressure developed in the coup and countercoup for water and gelatin-filled head models. Two separate 3D printed models …
Synthesis And Characterization Of Graphene-Reinforced Polymer Filaments For Additive Manufacturing, Sean Menezes
Synthesis And Characterization Of Graphene-Reinforced Polymer Filaments For Additive Manufacturing, Sean Menezes
Mechanical and Aerospace Engineering Theses - Archive
Fused Deposition Modeling (FDM) is a popular 3D printing process which uses a spool of thermoplastic polymer filament that is melted by the movable extruder printer head onto the bed to generate the required shape. The most used polymer filaments in FDM are Acrylonitrile Butadiene Styrene (ABS) and Poly Lactic Acid (PLA). However, these conventional polymer filaments have lower mechanical strength and are more susceptible to cracking as the cooler parts of the printed part shrink so much that they cause cracks to develop, leading to warping. The current investigation focuses on the synthesis of graphene, synthesis of polymer filaments …
Reverse Engineering To Create High Quality Polymer Parts Using Additive Manufacturing, Gurtej Singh Tarsem Singh Channa
Reverse Engineering To Create High Quality Polymer Parts Using Additive Manufacturing, Gurtej Singh Tarsem Singh Channa
Mechanical and Aerospace Engineering Theses - Archive
Reverse engineering is a process of recreating parts for which the tools no longer exist, reducing the cost of an original part by manufacturing it in-house or redesigning and improving the original part's function. This research demonstrates two methods to reverse engineer a part using Polyworks software, having it printed using an SLS printer and checking the accuracy of the printed part to the original scan. The part is first scanned using a Faro-Arm laser scanner to obtain the point cloud data. The two methods used to recreate and extract the STEP file are: • Exporting NURBS. • Exporting Features …
Development Of The Vehicle Configuration Compendium: A Comprehensive Data-Information-Knowledge System To Aid In High-Speed Vehicle Design, Stenila Simon
Mechanical and Aerospace Engineering Theses - Archive
The conceptual design phase is the most crucial phase in hypersonic vehicle design. Choices made during this phase will have significant impact on the success of the overall project and the feasibility of the end-product. Therefore, it is of utmost importance for the design decision-maker to be adequately informed of past-to-present projects throughout the aerospace community and lessons learned from them. This avoids wasting valuable time and resources for reinventing the wheel. There currently exists no one-stop solution in the aerospace industry to address the issue of lost data, information and knowledge in the field of high-speed vehicle design. The …
Relating Linear And Rotational Accelerations With Internal Pressures Developed Inside Human Head Surrogate Models, Arthur Thomas Koster
Relating Linear And Rotational Accelerations With Internal Pressures Developed Inside Human Head Surrogate Models, Arthur Thomas Koster
Mechanical and Aerospace Engineering Theses - Archive
Traumatic Brain Injury (TBI) is a chronic disease process that is difficult to both detect and treat. TBI can result from blast, kinetic, sonic, and electromagnet energy sources. This research focuses on correlating the bulk acceleration of a human-like head model to the localized internal pressure developed in the coup and contrecoup regions due to variable impact loading. Damage resulting in a TBI occurs on a multiscale level from the macroscale down to the damage of each individual neuron. Obtaining a relationship between bulk acceleration and localized internal pressure will allow for further correlation to the damage done on these …
Investigation Of Heat Transfer Performance Of Double Pipe Counter-Flow Heat Pipe Using Three Fluids Water, Dowtherm, And Water-Based Nanofluid, Alaa Abed Harchan Al Hasseun
Investigation Of Heat Transfer Performance Of Double Pipe Counter-Flow Heat Pipe Using Three Fluids Water, Dowtherm, And Water-Based Nanofluid, Alaa Abed Harchan Al Hasseun
Mechanical and Aerospace Engineering Theses - Archive
Heat pipes are two-phase devices, capable of converting a significant amount of energy with low losses. They have been used in several applications such as systems thermal control and cooling. The purpose of the present work is to investigate the thermal performance of a double pipe counterflow against the fluid type. The pipe is divided into three zones including evaporator, adiabatic, and condenser zones. All thermal boundary conditions are defined in terms of heating or cooling temperatures in which the operating temperatures are defined between 303 K to 470 K. using Ansys Fluent, the pipe is analyzed in two-and three-dimensional …
Prediction Of Solder Joint Fatigue Life Of Photonic Package Using ?-? Materials, Ojas Tyagi
Prediction Of Solder Joint Fatigue Life Of Photonic Package Using ?-? Materials, Ojas Tyagi
Mechanical and Aerospace Engineering Theses - Archive
Fatigue life prediction has become very important factor in reliability of any electronic components to withstand extreme thermal stresses in industrial standard. Hence, photonic packages are widely used in telecommunication and computer applications. The primary focus of this study is to determine the thermal cycles to crack initiation of solder bump used in laser array waferboard for telecommunication applications. This includes GaAs Laser chip on waferboard and Si substrate with pure Indium solder balls in between. Indium has proved higher fatigue life in various experimental studies in the field of reliability and lead-free material. Therefore, a solder ball was designed …
Analysis Of Blood Pressure Waveform For Detection And Diagnosis Of Cardiovascular Anomalies, Atul Shrotriya
Analysis Of Blood Pressure Waveform For Detection And Diagnosis Of Cardiovascular Anomalies, Atul Shrotriya
Mechanical and Aerospace Engineering Theses - Archive
Cardiovascular diseases are the leading cause of mortalities worldwide as well as in the United States. Early diagnosis and prediction of these diseases is critical to mitigate the risks to the patient. A common method to assess a person’s heart health is through the use of cuff type oscillometric devices placed on the arm of the patient. As the mean pressure in the cuff is increased the blood flow in the brachial artery becomes blocked. When the cuff pressure is reduced the blood starts flowing again; during this cycle, pressure fluctuations in the cuff are measured using a pressure transducer. …
Determination Of Guidance Laws For Uav Systems In Communication Networks Using Collision Cone Theory, Utsav Mudgal
Determination Of Guidance Laws For Uav Systems In Communication Networks Using Collision Cone Theory, Utsav Mudgal
Mechanical and Aerospace Engineering Theses - Archive
Unmanned Aerial Vehicles (UAVs), also commonly known as drones, are used in various applications, including military applications such as surveillance and intelligence-gathering as well as civilian applications such as search and rescue. The use of UAVs to form communication networks is a topic of active research interest. This thesis aims to investigate the development of guidance laws for multiple UAVs to form such communication networks. Toward this end, this thesis employs tools from collision cone theory and incorporates them with parameters used to describe a communication network. Different types of networks are evaluated for use of the guidance laws. Simulation …
Guidance Laws For N-Mobile Agents To Grip A Moving Target, Pranay Gadiya
Guidance Laws For N-Mobile Agents To Grip A Moving Target, Pranay Gadiya
Mechanical and Aerospace Engineering Theses - Archive
In this thesis, we consider the problem of n mobile agents carrying a gripper, with the objective of gripping a moving circular target. The target may move with constant velocity, or even maneuver. We develop guidance laws by which the agents can first cage the target and subsequently grip it. These guidance laws are developed based on a collision cone framework, using which the mobile agents cooperatively steer their velocity vectors in an appropriate fashion to meet their objective. It is assumed that each of the mobile agents are equipped with a lidar sensor, using which they obtain the range …
Buckling Load Optimization Of Variable Stiffness Composite Plate Using Fem And Semi-Analytical Method, Jeegar Vallabhbhai Patel
Buckling Load Optimization Of Variable Stiffness Composite Plate Using Fem And Semi-Analytical Method, Jeegar Vallabhbhai Patel
Mechanical and Aerospace Engineering Theses - Archive
The advent of new composite manufacturing techniques like Automated Fiber Placement (AFP) offers greater flexibility in structural designs by allowing curvilinear fiber paths. Hence, it is now possible to change laminate stiffness locally, thereby enabling Variable Stiffness (VS) composite structures. Such structures demonstrate superior buckling performance over traditional constant stiffness structures. However, obtaining the optimum fiber paths to improve buckling performance remains an open area of research due to the complexity of determining such fiber paths. This research investigated two approaches for optimizing fiber paths; First, a Finite Element Method (FEM) approach that utilizes linear shape functions to interpolate local …
A Modular Platform For Intrusive Diagnostics And Tps Testing In The Onr-Uta Arc-Jet Facility, Blake Anthony Hamilton
A Modular Platform For Intrusive Diagnostics And Tps Testing In The Onr-Uta Arc-Jet Facility, Blake Anthony Hamilton
Mechanical and Aerospace Engineering Theses - Archive
This work presents an approach to the design, and successful experimental implementation, of a modular platform for intrusive diagnostics and TPS testing in the ONR-UTA Arc-Heated Wind Tunnel "Leste" Facility. The harsh conditions typical of arc-jet facilities (hypersonic, high-enthalpy, chemically-reacting, continuous flows) present a challenge to the design of insertion platforms. In this work a detailed analysis of the aerothermal loads is used to aid in the design process. Specific design points for this modular platform and its ancillary instrumentation have been identified. Based on this design approach, a modular platform for intrusive diagnostics and TPS testing has been developed. …
Investigation Into Wedge Turbulator Effects In High Aspect Ratio Cooling Channels, Daniel Garcia
Investigation Into Wedge Turbulator Effects In High Aspect Ratio Cooling Channels, Daniel Garcia
Electronic Theses and Dissertations, 2020-2023
With reusability being a novel design parameter for liquid rocket engines (LRE), the need to lower internal wall temperatures for an increased engine longevity is a desired outcome. One of the mechanisms that has been effectively implemented is the use of high aspect ratio cooling channels (HARCC) to promote fin-like effects from internal cooling channel sidewalls. In the gas turbine industry, the use of wedge turbulators has gained recognition for its heat augmentation properties with relatively low pressure drop penalty. In an ideal case, LRE's could adopt the wedge turbulator cooling technique to enhance the benefits of HARCC with minimal …
Theoretical Prediction Of Mechanical Behavior Of Regular And Chiral Honeycombs Based On Loading Of Single Cell., Sai Krishna K. Pinnamaneni
Theoretical Prediction Of Mechanical Behavior Of Regular And Chiral Honeycombs Based On Loading Of Single Cell., Sai Krishna K. Pinnamaneni
Mechanical and Aerospace Engineering Dissertations - Archive
Cellular solids are both naturally occurring and man-made materials depending on the characteristic length or Stochastic manner, these materials exhibit a low-relative density usually 30% than the constituent solid material. Low-density cellular solids have been demonstrating superior mechanical properties in various applications from marine to aerospace and lightweight sandwich structures, which has intrigued in development of novel structured materials. Cellular solids offer great design flexibility ashowows how for the targeted geometric for the application-based industry. These materials are used in sandwich structures and come in the shape of hexagonal. An additional aspect of determining the properties and behavior is by …
Multi-Parametric And Multi-Objective Optimization Of Heatsinks For Forced And Natural Convection Based Single-Phase Immersion Cooling Of Server, Tushar Rohidas Wagh
Multi-Parametric And Multi-Objective Optimization Of Heatsinks For Forced And Natural Convection Based Single-Phase Immersion Cooling Of Server, Tushar Rohidas Wagh
Mechanical and Aerospace Engineering Theses - Archive
An increase in utility of internet-based services, cloud computing and greater performance demands due to rising AI and ML applications have led to a steep growth in GPU and CPU thermal design power. Efficient thermal management of these processors has become a bottleneck in performance enhancement and corresponding power densification of these components. Furthermore, increased pressure on data center owners to reduce power demands and move towards green computing has exacerbated the data center cooling challenges. Single-phase immersion cooling allows data center owners to not only dissipate the increasing heat fluxes efficiently but can also potentially improve equipment reliability as …
On Mode Transition Phenomenon And Operating Conditions In Rotating Detonation Rocket Engines, Taha Rezzag-Lebza
On Mode Transition Phenomenon And Operating Conditions In Rotating Detonation Rocket Engines, Taha Rezzag-Lebza
Electronic Theses and Dissertations, 2020-2023
The work presented herein consist of first studying the instantaneous properties of the detonation waves in a rotating detonation rocket engine by tracking each individual wave and recording its position, velocity, and peak intensity as it travels around the annulus. Results for a steady portion of a test performed on a rotating detonation rocket engine show that the wave properties exhibit oscillatory behavior. Results obtained from the rotating detonation rocket engine show that the properties are highly dependent on the azimuthal position. In an attempt to understanding the cause of such a behavior, similar investigations were performed on an air-breathing …
Developing A Light Curve Simulation Tool For Ground And Space-Based Observations Of Spacecraft And Debris, Andrew T. Ochoa
Developing A Light Curve Simulation Tool For Ground And Space-Based Observations Of Spacecraft And Debris, Andrew T. Ochoa
Master's Theses
A light curve is a plot of brightness versus time of an object. Light curves are dependent on orbit, attitude, surface area, size, and shape of the observed object. Using light curve data, several analysis methods have been developed to derive these parameters. These parameters can be used for tracking orbital debris, monitoring satellite health, and determining the mission of an unknown spacecraft.
This paper discusses the development, verification, and utilization of a tool that simulates light curve data. This tool models ground-based observations, space-based observations, self-shadowing geometry, tumbling debris, and controlled spacecraft. The main output from the tool is …
Airframe And Systems Design, Analysis, And Testing Of The Horizon Morphing-Wing Aircraft, Sabrina A. Snow
Airframe And Systems Design, Analysis, And Testing Of The Horizon Morphing-Wing Aircraft, Sabrina A. Snow
All Graduate Plan B and other Reports, Spring 1920 to Spring 2023
Morphing trailing edge technology can provide the ability to dynamically alter the twist distribution, and therefore lift distribution, of an aircraft during flight. There are certain optimal lift distributions which can be chosen to create proverse yawing effects and eliminate the need for vertical control surfaces. The purpose of this project is to support the design and testing of a morphing, crescent flying wing airframe which will be used to evaluate yaw control in an aircraft without vertical control surfaces. There are three main objectives of this project, which are to perform static and dynamic analysis on the crescent wing …
Second-Order Reliability Methods: A Review And Comparative Study, Zhangli Hu, Rami Mansour, Mårten Olsson, Xiaoping Du
Second-Order Reliability Methods: A Review And Comparative Study, Zhangli Hu, Rami Mansour, Mårten Olsson, Xiaoping Du
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Second-order reliability methods are commonly used for the computation of reliability, defined as the probability of satisfying an intended function in the presence of uncertainties. These methods can achieve highly accurate reliability predictions owing to a second-order approximation of the limit-state function around the Most Probable Point of failure. Although numerous formulations have been developed, the lack of full-scale comparative studies has led to a dubiety regarding the selection of a suitable method for a specific reliability analysis problem. In this study, the performance of commonly used second-order reliability methods is assessed based on the problem scale, curvatures at the …
Impact Of Surface And Pore Characteristics On Fatigue Life Of Laser Powder Bed Fusion Ti–6al–4v Alloy Described By Neural Network Models, Seunghyun Moon, Ruimin Ma, Ross Attardo, Charles Tomonto, Mark Nordin, Paul Wheelock, Michael Glavicic, Maxwell Layman, Richard Billo, Tengfei Luo
Impact Of Surface And Pore Characteristics On Fatigue Life Of Laser Powder Bed Fusion Ti–6al–4v Alloy Described By Neural Network Models, Seunghyun Moon, Ruimin Ma, Ross Attardo, Charles Tomonto, Mark Nordin, Paul Wheelock, Michael Glavicic, Maxwell Layman, Richard Billo, Tengfei Luo
Mechanical and Aerospace Engineering Faculty Research & Creative Works
In this study, the effects of surface roughness and pore characteristics on fatigue lives of laser powder bed fusion (LPBF) Ti–6Al–4V parts were investigated. The 197 fatigue bars were printed using the same laser power but with varied scanning speeds. These actions led to variations in the geometries of microscale pores, and such variations were characterized using micro-computed tomography. To generate differences in surface roughness in fatigue bars, half of the samples were grit-blasted and the other half were machined. Fatigue behaviors were analyzed with respect to surface roughness and statistics of the pores. For the grit-blasted samples, the contour …
Accelerated Performance Degradation Of Single-Phase Cold Plates For Direct-To-Chip Liquid Cooled Data Centers, Lochan Sai Reddy Chinthaparthy
Accelerated Performance Degradation Of Single-Phase Cold Plates For Direct-To-Chip Liquid Cooled Data Centers, Lochan Sai Reddy Chinthaparthy
Mechanical and Aerospace Engineering Theses - Archive
Expanding demands for cloud-based computing and storage, the Internet of Things, and AI-based applications have escalated thermal loads in high-density data centers which necessitated the utilization of more efficient cooling technologies. Direct-to-chip liquid cooling using cold plates has proven to be one of the most efficient methods to dissipate the high heat fluxes of modern high-power CPUs and GPUs. While the published literature has well-documented research on the thermal aspects of direct liquid cooling, a detailed account of reliability degradation is missing. The present investigation provides an in-depth analysis of the reliability degradation of copper cold plates used in high-power …
Creasing Of Polyimide Thin Film For Use In Solar Sails, Andrew Allen
Creasing Of Polyimide Thin Film For Use In Solar Sails, Andrew Allen
Electronic Theses and Dissertations, 2020-2023
Polymer thin membranes are used in a variety of deployable structures that require large areas and compact stowage. Packaging membrane structures often involves creasing the membrane along predefined fold lines to enforce the desired kinematics under folding action. Inducing permanent deformation by folding to a high curvature is a common method to create creases, particularly in the design of solar sails. The distinct mechanical characteristics at the crease regions have a profound effect on the subsequent deployment and tensioning of the membrane structures. The mechanical and geometric properties at the crease are related to the crease formation process, but the …
Autonomous Guidance Of Unmanned Combat Air Vehicles In Basic Fighter Maneuvering, Jeffery G. Dean
Autonomous Guidance Of Unmanned Combat Air Vehicles In Basic Fighter Maneuvering, Jeffery G. Dean
Mechanical and Aerospace Engineering Dissertations - Archive
Basic fighter maneuvering, or BFM, is the dynamic engagement of two or more aircraft in close-range air combat. The relatively recent introduction of advanced unmanned combat air vehicles (UCAVs) has opened the possibility for automated systems to be players in this arena of air-to-air combat, which has thus far been limited to manned aircraft. In order to design an unmanned system that could fight and win a BFM engagement, the system must include an advanced system for guidance. This dissertation leverages techniques from gain scheduling and incorporates adjustable aimpoint guidance, in order to address the capability for UCAVs to execute …