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Articles 4381 - 4410 of 11166
Full-Text Articles in Engineering
Double Wall Cooling Of A Full Coverage Effusion Plate With Main Flow Pressure Gradient, Including Internal Impingement Array Cooling, Sneha R. Vanga, David Ritchie, Austin Click, Zhong Ren, Phil Ligrani, Federico Liberatore, Rajeshriben Patel, Ram Srinivasan, Yin-Hsiang Ho
Double Wall Cooling Of A Full Coverage Effusion Plate With Main Flow Pressure Gradient, Including Internal Impingement Array Cooling, Sneha R. Vanga, David Ritchie, Austin Click, Zhong Ren, Phil Ligrani, Federico Liberatore, Rajeshriben Patel, Ram Srinivasan, Yin-Hsiang Ho
PRC-Affiliated Research
The present study provides new effusion cooling data for both the surfaces of the fullcoverage effusion cooling plate. For the effusion-cooled surface, presented are spatially resolved distributions of surface adiabatic film cooling effectiveness and surface heat transfer coefficients (measured using transient techniques and infrared thermography). For the impingement-cooled surface, presented are spatially resolved distributions of surface Nusselt numbers (measured using steady-state liquid crystal thermography). To produce this cool-side augmentation, impingement jet arrays at different jet Reynolds numbers, from 2720 to 11,100, are employed. Experimental data are given for a sparse effusion hole array, with spanwise and streamwise impingement hole spacing …
Double Wall Cooling Of A Full Coverage Effusion Plate With Main Flow Pressure Gradient, Including Internal Impingement Array Cooling, Sneha R. Vanga, David Ritchie, Austin Click, Zhong Ren, Phil Ligrani, Federico Liberatore, Rajeshriben Patel, Ram Srinivasan, Yin-Hsiang Ho
Double Wall Cooling Of A Full Coverage Effusion Plate With Main Flow Pressure Gradient, Including Internal Impingement Array Cooling, Sneha R. Vanga, David Ritchie, Austin Click, Zhong Ren, Phil Ligrani, Federico Liberatore, Rajeshriben Patel, Ram Srinivasan, Yin-Hsiang Ho
PRC-Affiliated Research
The present study provides new effusion cooling data for both the surfaces of the fullcoverage effusion cooling plate. For the effusion-cooled surface, presented are spatially resolved distributions of surface adiabatic film cooling effectiveness and surface heat transfer coefficients (measured using transient techniques and infrared thermography). For the impingement-cooled surface, presented are spatially resolved distributions of surface Nusselt numbers (measured using steady-state liquid crystal thermography). To produce this cool-side augmentation, impingement jet arrays at different jet Reynolds numbers, from 2720 to 11,100, are employed. Experimental data are given for a sparse effusion hole array, with spanwise and streamwise impingement hole spacing …
Mass Accommodation At A High-Velocity Water Liquid-Vapor Interface, J. Nie, A. Chandra, Z. Liang, P. Keblinski
Mass Accommodation At A High-Velocity Water Liquid-Vapor Interface, J. Nie, A. Chandra, Z. Liang, P. Keblinski
Mechanical and Aerospace Engineering Faculty Research & Creative Works
We Use Molecular Dynamics to Determine the Mass Accommodation Coefficient (MAC) of Water Vapor Molecules Colliding with a Rapidly Moving Liquid-Vapor Interface. This Interface Mimics Those Present in Collapsing Vapor Bubbles that Are Characterized by Large Interfacial Velocities. We Find that at Room Temperature, the MAC is Generally Close to Unity, and Even with Interfaces Moving at 10 Km/s Velocity, It Has a Large Value of 0.79. using a Simplified Atomistic Fluid Model, We Explore the Consequences of Vapor Molecule Interfacial Collision Rules on Pressure, Temperature, and Density of a Vapor Subjected to an Incoming High-Velocity Liquid-Vapor Interface.
Control Failures And How To Deal With It, Nihad E. Daidzic
Control Failures And How To Deal With It, Nihad E. Daidzic
Aviation Department Publications
FAA Safety Seminar (GL1591497) held at Minnesota State University, Mankato Wiecking Center Auditorium at 18:00 CST on Thursday, April 18, 2019.
Chaotic Lunar Capture Designs And Operations Of A Cubesat Using A Low Thrust System, Kennedy V. Haught
Chaotic Lunar Capture Designs And Operations Of A Cubesat Using A Low Thrust System, Kennedy V. Haught
Morehead State Theses and Dissertations
A thesis presented to the faculty of the College of Science at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Kennedy V. Haught on April 17, 2019.
A High Magnification Uv Lens For High Temperature Optical Strain Measurements, Robert S. Hansen, Trevor J. Bird, Ren Voie, Katharine Z. Burn, Ryan B. Berke
A High Magnification Uv Lens For High Temperature Optical Strain Measurements, Robert S. Hansen, Trevor J. Bird, Ren Voie, Katharine Z. Burn, Ryan B. Berke
Mechanical and Aerospace Engineering Faculty Publications
Digital Image Correlation (DIC) measures full-field strains by tracking displacements of a specimen using images taken before and after deformation. At high temperatures, materials emit light in the form of blackbody radiation, which can interfere with DIC images. To screen out that light, DIC has been recently adapted by using ultraviolet (UV) range cameras, lenses, and filters. Before now, UV-DIC had been demonstrated at the centimeter scale using commercially available UV lenses and filters. Commercial high-magnification lenses using visible light have also been used for DIC. However, there is currently no commercially available high-magnification lens that will allow images to …
Design Of A Thrust Stand For Electric Propulsion, Hannah Watts
Design Of A Thrust Stand For Electric Propulsion, Hannah Watts
Honors Theses
Thrust stands are the industry standard device for measuring the low levels of thrust generated by electric propulsion devices. Western Michigan University’s Aerospace Laboratory for Plasma Experiments is home to several electric propulsion devices and is in the process of obtaining a pulsed plasma thruster in partnership with the Western Aerospace Launch Initiative. The lab currently has no way of measuring the true thrust force generated by these devices. A thrust stand has been designed specific to the micro-Newton thrust range and the constraints inherent to the facilities in which it will operate.
Thermal Adaptation Of A Vacuum Chamber, Jacob Russell
Thermal Adaptation Of A Vacuum Chamber, Jacob Russell
Honors Theses
The process of adapting a preexisting vacuum chamber to perform thermal vacuum testing is a rare process in the testing industry. A closed vacuum system that was designed without thermal capacitance in mind will hinder the development of additional thermal system capabilities and prove difficult from a cost standpoint. Generally, building a thermal vacuum system from scratch will cost on the order of $10,000 to $100,000 depending on the system requirements regarding control and thermal capacitance within the chamber. This project will explore the cost of such an adaptation, attempting to minimize expense, and potentially provide the “Western Aerospace Launch …
Water Walking As A New Mode Of Free Surface Skipping, Randy Craig Hurd, Jesse Belden, Allan F. Bower, Sean Holekamp, Michael A. Jandron, Tadd T. Truscott
Water Walking As A New Mode Of Free Surface Skipping, Randy Craig Hurd, Jesse Belden, Allan F. Bower, Sean Holekamp, Michael A. Jandron, Tadd T. Truscott
Mechanical and Aerospace Engineering Faculty Publications
Deformable elastomeric spheres are evaluated experimentally as they skip multiple times over a lake surface. Some spheres are embedded with small inertial measurement units to measure the acceleration experienced during water surface impact. A model for multiple impact events shows good agreement between measured acceleration, number of skipping events and distanced traveled. The experiment reveals a new mode of skipping, “water walking”, which is observed for relatively soft spheres impacting at low impact angles. The mode occurs when the sphere gains significant angular velocity over the first several impacts, causing the sphere to maintain a deformed, oblong shape. The behavior …
Autonomous Watercraft Simulation And Programming, Nicholas J. Savino
Autonomous Watercraft Simulation And Programming, Nicholas J. Savino
Student Scholar Showcase
Automation of various modes of transportation is thought to make travel more safe and efficient. Over the past several decades, advances to semi-autonomous and autonomous vehicles have led to advanced autopilot systems on planes and boats, and an increasing popularity of self-driving cars. We predicted the motion of an autonomous vehicle using simulations in Python. The simulation models the motion of a small scale watercraft, which can then be built and programmed using an Arduino Microcontroller. We examined different control methods for a simulated rescue craft to reach a target. We also examined the effects of different factors, such as …
Algorithm For Geodetic Positioning Based On Angle-Of-Arrival Of Automatic Dependent Surveillance-Broadcasts, Richard Allen Gross
Algorithm For Geodetic Positioning Based On Angle-Of-Arrival Of Automatic Dependent Surveillance-Broadcasts, Richard Allen Gross
Masters Theses
This paper develops a non-precision, three-dimensional, geodetic positioning algorithm for airborne vehicles. The algorithm leverages the proliferation of Automatic Dependent Surveillance – Broadcast (ADS-B) equipped aircraft, utilizing them as airborne navigation aids to generate an RF Angle-of-Arrival (AOA) and Angle-of-Elevation (AOE) based geodetic position. The resulting geodetic position can serve as a redundant navigation system for use during locally limited Global Navigation Satellite System (GNSS) availability, be used to validate on-board satellite navigation systems in an effort to detect local spoofing attempts, and be used to validate ADS-B position reports.
The navigation algorithm is an implementation of an Extended Kalman …
Uncover The Power Of Multipath : Detecting Nlos Drones Using Low-Cost Wifi Devices, Ashok Vardhan Raja
Uncover The Power Of Multipath : Detecting Nlos Drones Using Low-Cost Wifi Devices, Ashok Vardhan Raja
Doctoral Dissertations and Master's Theses
In recent years, consumer UAV technology has seen considerable advances. Consumer UAVs have become an ideal vector for privacy invasions due to their affordability, size, maneuverability, and their ability to stream live high-quality video. There is considerable proliferation of drones in both civil and military domains. Hence it is critical to detect invading unmanned aerial vehicles (UAVs) or drones in a timely manner for both security and safeguarding privacy. Currently available solutions like active radar, video or acoustic sensors are very expensive (especially for individuals) and have considerable constraints (e.g., requiring visual line of sight).
Recent research on drone detection …
Geometric Effects Of Thermal Barrier Coating Damage On Turbine Blade Temperatures, Shane Colon
Geometric Effects Of Thermal Barrier Coating Damage On Turbine Blade Temperatures, Shane Colon
Doctoral Dissertations and Master's Theses
Thermal barrier coatings (TBC) found on turbine blades are a key element in the performance and reliability of modern gas turbines. During the life of the turbine components, the TBC surface may be damaged due to manufacturing imperfections, handling damage, service spalling, or service impact damage, producing chips in the coating. While a chip in the TBC coating is expected to cause an increase in airfoil temperature, it is unknown to what degree the blade will be affected and what parameters of the chip shape affect this result. The goal of this preliminary study is to identify the major driving …
Non-Linear Bending Analysis Of Functionally Graded Beams With Spring Constraints And Thermal Effects, Swetha Suresh
Non-Linear Bending Analysis Of Functionally Graded Beams With Spring Constraints And Thermal Effects, Swetha Suresh
Doctoral Dissertations and Master's Theses
No abstract provided.
Energy Analysis And Orbit Simulation Of Actuating Cubesat Solar Arrays, Justin T. Ehren
Energy Analysis And Orbit Simulation Of Actuating Cubesat Solar Arrays, Justin T. Ehren
Honors Theses
CubeSats are used in space research to explore new technologies and detect data to gain a better understanding of various areas of research and subjects affecting human life. CubeSats rely on a solar array to generate energy from the sun and perform their various functions in space. This research studies the energy capturing potential of various solar array configurations and positioning devices for CubeSats. The location and orientation of a CubeSat is simulated with MATLAB for both geo-synchronous and sunsynchronous orbits. Two degree-of-freedom (DoF) positioning devices are sufficient to continuously adjust the photovoltaic array to face towards the sun. Lower …
Scale Interactions Within A Perturbed Plane Wall Jet, Shibani Bhatt
Scale Interactions Within A Perturbed Plane Wall Jet, Shibani Bhatt
Doctoral Dissertations and Master's Theses
The current work focuses on exploiting this behavior to manipulate wall turbulence by targeting the large-scales of the flow. In wall turbulence the large-scales of the flow interact with the smaller scales in a non-linear manner including through a process of amplitude and frequency modulation. A plane wall jet (PWJ) is chosen as the model flow field for this work as its unique geometry allows for the controlled introduction of large-scale perturbations through acoustic forcing. The corresponding interactions because of forcing are characterized using single hot-wire measurements. The nearwall response of the PWJ over a range of large-scale forcing showed …
Model Predictive Control Synthesis For The Innovative Control Effector Tailless Fighter Aircraft, Christopher Proctor
Model Predictive Control Synthesis For The Innovative Control Effector Tailless Fighter Aircraft, Christopher Proctor
Masters Theses
A nonlinear model predictive control law was developed for the Lockheed Martin Innovative Control Effector tailless fighter aircraft to track way points. In general, aircraft are described by nonlinear dynamics that are dependent on the regime of flight. Additionally strict requirements on state and actuator constraints are common to all aircraft. Tailless aircraft are usually overdetermined systems, meaning solutions to control problems are not unique, and the system is non-affine. The proposed nonlinear control law considers those constraints during run-time, and solves the nonlinear control problem for a range of points within different flight regimes. The control law was developed …
Comparison Of Support Methods For Static Aerodynamic Testing And Validation Of A Magnetic Suspension And Balance System, Cameron K. Neill
Comparison Of Support Methods For Static Aerodynamic Testing And Validation Of A Magnetic Suspension And Balance System, Cameron K. Neill
Mechanical & Aerospace Engineering Theses & Dissertations
Magnetic suspension wind tunnels offer an alternative to traditional physical support methods. They allow for the collection of support interference free data and broader dynamic test capabilities than existing methods. Determination of dynamic aerodynamic characteristics is a crucial portion of the design of new re-entry capsules. A NASA initiative restored the 6-inch Magnetic Suspension and Balance System to support the design of a new MSBS for a supersonic wind tunnel. Before a new MSBS can be constructed, the characteristics of the current MSBS must be examined.
This thesis discusses the calibration and validation of the 6-inch MSBS. After calibration, three …
Control Law Synthesis For Lockheed Martin’S Innovative Control Effectors Aircraft Concept, Cameron James Segard
Control Law Synthesis For Lockheed Martin’S Innovative Control Effectors Aircraft Concept, Cameron James Segard
Masters Theses
This thesis documents a conventional and modern flight control system design process carried out on a tailless aircraft Simulink model with innovative control effectors provided by Lockheed Martin. To set scope and design requirements a performance analysis was carried out to categorize the aircraft. Evaluation of open-loop dynamics reveled modal instabilities as well as state and control coupling. Flight condition dependent pole migration mapping reveled large changes in the aircraft’s static stability. Leading to the development of a four channel proportional-integral- derivative (PID) stability and control augmentation system (SCAS) controlling pitch-rate, roll-rate, side-slip angle, and airspeed states. PID gains are …
Continuous Tow Path Generation For Constant And Variable Stiffness Composite Laminates On Single And Double Curved Surfaces, Caleb R. Pupo
Continuous Tow Path Generation For Constant And Variable Stiffness Composite Laminates On Single And Double Curved Surfaces, Caleb R. Pupo
Theses and Dissertations
A novel approach for the generation of steered tow paths on curved shell surfaces is presented. The approach is used to translate optimal theoretical analysis expressed from ply to ply as fiber angle distributions for steered laminates into discrete tow paths on planar, single and double curved surfaces. By adapting the multi mesh approach earlier developed by van Tooren and Elham [1–3] to the new tow path generation code. Two meshes are utilized, a coarse mesh which is generated during the optimization and contains the optimal fiber angle distributions, and a denser mesh obtained from tessellating the surface to better …
Development And Initial Evaluation Of A Reinforced Cue Detection Model To Assess Situation Awareness In Commercial Aircraft Cockpits, Aysen K. Taylor
Development And Initial Evaluation Of A Reinforced Cue Detection Model To Assess Situation Awareness In Commercial Aircraft Cockpits, Aysen K. Taylor
Engineering Management & Systems Engineering Theses & Dissertations
Commercial transport aircraft of today vary greatly from early aircraft with regards to how the aircraft are controlled and the feedback provided from the machine to the human operator. Over time, as avionics systems became more automated, pilots had less direct control over their aircraft. Much research exists in the literature about automation issues, and several major accidents over the last twenty years spurred interest about how to maintain the benefits of automation while improving the overall human-machine interaction as the pilot is considered the last line of defense.
An important reason for maintaining or even improving overall pilot situation …
Design And Manufacture Of An Inertial Cascade Impactor For Industrial Hygiene Purposes, Hector Joel Gortaire
Design And Manufacture Of An Inertial Cascade Impactor For Industrial Hygiene Purposes, Hector Joel Gortaire
Mechanical & Aerospace Engineering Theses & Dissertations
Inertial cascade impactors are devices commonly used for industrial hygiene and pharmaceutical studies. Their main purpose is to separate particulate matter suspended in aerosols according to their sizes, which can vary from over 10 µm to 0.5 µm. Their versatility and ease of operation make them suitable for on-site sampling; however, designing them requires a careful consideration of the different geometric parameters that characterize them.
In this thesis, a 5-stage inertial cascade impactor was designed, modelled, constructed, and tested. The main design parameter was the volumetric flow rate, 40 l/min, which was provided by a vacuum pump. By continuous iterations, …
An Investigation Of General Criteria For Assessing Space Flight Systems Of Diverse Mission Concept Designs, Cindy L. Daniels
An Investigation Of General Criteria For Assessing Space Flight Systems Of Diverse Mission Concept Designs, Cindy L. Daniels
Engineering Management & Systems Engineering Theses & Dissertations
The purpose of this research is to investigate the general criteria for assessing the technical implementation risk factors of proposed space science missions at the mission concept stage. According to the National Aeronautics and Space Administration (NASA) Space Flight Program and Project Management Handbook (NASA, 2012), the mission concept review objectives are “To evaluate the feasibility of the proposed mission concept(s) and its fulfillment of the program's needs and objectives. To determine whether the maturity of the concept and associated planning are sufficient to begin Phase A” (p.33). Experts previously defined two technical risk factors, to assess aspects of the …
Characterization And Optimization Of A Propeller Test Stand, Colin Bruce Leighton Benjamin
Characterization And Optimization Of A Propeller Test Stand, Colin Bruce Leighton Benjamin
Mechanical & Aerospace Engineering Theses & Dissertations
In recent history, there has been a rapid rise in the use of drones, and they are expanding in popularity each year. The widespread use and future capabilities of these unmanned aerial vehicles (UAVs) will call for increased study and classification of propellers to maximize their performance. As a result, it is necessary to have continuity in the development, maximization, and optimization of propeller test stand’s capability to collect accurate and precise measurements. It is of significant advantage to have the capability of accurately characterizing a propeller based on its thrust and torque. In this study, a propeller test stand …
A Comprehensive Experimental And Modeling Study On Dissolution In Li-Ion Batteries, Yoon Koo Lee, Jonghyun Park, Wei Lu
A Comprehensive Experimental And Modeling Study On Dissolution In Li-Ion Batteries, Yoon Koo Lee, Jonghyun Park, Wei Lu
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Dissolution is a critical challenge in metal oxide battery materials, which affects battery performance across multiple scales. At the particle level, the loss of active material as a result of dissolution directly results in capacity fade. At the electrode level, the re-deposition of dissolved metal ions onto the cathode increases cell polarization and hinders lithium transport. At the cell level, the dissolved ions further transport to and deposit on the anode, which consumes cycle-able lithium and leads to capacity fade. These processes lead to poor lithium reversibility, diffusivity, and conductivity. In this work, detailed experimental studies from the particle level …
Performance Analysis Of Angle Of Arrival Algorithms Applied To Radiofrequency Interference Direction Finding, Taylor S. Barber
Performance Analysis Of Angle Of Arrival Algorithms Applied To Radiofrequency Interference Direction Finding, Taylor S. Barber
Theses and Dissertations
Radiofrequency (RF) interference threatens the functionality of systems that increasingly underpin the daily function of modern society. In recent years there have been multiple incidents of intentional RF spectrum denial using terrestrial interference sources. Because RF based systems are used in safety-of-life applications in both military and civilian contexts, there is need for systems that can quickly locate these interference sources. In order to meet this need, the Air Force Research Laboratory Weapons Directorate is sponsoring the following research to support systems that will be able to quickly geolocate RF interferers using passive angle-of-arrival estimation to triangulate interference sources. This …
Cyber-Attack Drone Payload Development And Geolocation Via Directional Antennae, Clint M. Bramlette
Cyber-Attack Drone Payload Development And Geolocation Via Directional Antennae, Clint M. Bramlette
Theses and Dissertations
The increasing capabilities of commercial drones have led to blossoming drone usage in private sector industries ranging from agriculture to mining to cinema. Commercial drones have made amazing improvements in flight time, flight distance, and payload weight. These same features also offer a unique and unprecedented commodity for wireless hackers -- the ability to gain ‘physical’ proximity to a target without personally having to be anywhere near it. This capability is called Remote Physical Proximity (RPP). By their nature, wireless devices are largely susceptible to sniffing and injection attacks, but only if the attacker can interact with the device via …
Convolutional Neural Network Architecture Study For Aerial Visual Localization, Jedediah M. Berhold
Convolutional Neural Network Architecture Study For Aerial Visual Localization, Jedediah M. Berhold
Theses and Dissertations
In unmanned aerial navigation the ability to determine the aircraft's location is essential for safe flight. The Global Positioning System (GPS) is the default modern application used for geospatial location determination. GPS is extremely robust, very accurate, and has essentially solved aerial localization. Unfortunately, the signals from all Global Navigation Satellite Systems (GNSS) to include GPS can be jammed or spoofed. To this response it is essential to develop alternative systems that could be used to supplement navigation systems, in the event of a lost GNSS signal. Public and governmental satellites have provided large amounts of high-resolution satellite imagery. These …
High Resolution Low-Bandwidth Real-Time Reconnaissance Using Structure From Motion With Planar Homography Estimation, Christian M.A. Arnold
High Resolution Low-Bandwidth Real-Time Reconnaissance Using Structure From Motion With Planar Homography Estimation, Christian M.A. Arnold
Theses and Dissertations
Aerial real-time surveillance exists in a paradigm balancing the constraints of delivering high quality data and transporting data quickly. Typically, to have more of one, sacrifices must be made to the other. This is true of the environment in which an Unmanned Aerial Vehicle (UAV) operates, where real-time communication may be done through a low-bandwidth satellite connection resulting in low-resolution data, and serves as the primary limiting factor in all intelligence operations. Through the use of efficient computer vision techniques, we propose a new Structure from Motion (SfM) method capable of compressing high-resolution data, and delivering that data in real-time. …
Piezoelectric Sensor Crack Detection On Airframe Systems, Kevin J. Lin
Piezoelectric Sensor Crack Detection On Airframe Systems, Kevin J. Lin
Theses and Dissertations
In 2008, the Department of Defense published a guidebook for a methodology named Condition-Based Maintenance Plus (CBM+) which capabilities include improving productivity, shortening maintenance cycles, lowering costs, and increasing availability and reliability. This push replaces existing inspection criteria, often conducted as non-destructive testing (NDT), with structural health monitoring (SHM) systems. The SHM system addressed utilizes guided Lamb waves generated by piezoelectric wafer active sensors (PWAS) to detect the existence, size, and location of damage from through-thickness cracks around a rivet hole. The SHM field lacks an experiment testing how small changes in receiver sensor distances affect damage detection. In addition, …