Aerospace Engineering Commons^™

Thermal Modeling Of Additive Manufacturing Using Graph Theory: Validation With Directed Energy Deposition, Jordan Severson

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Metal additive manufacturing (AM/3D printing) offers unparalleled advantages over conventional manufacturing, including greater design freedom and a lower lead time. However, the use of AM parts in safety-critical industries, such as aerospace and biomedical, is limited by the tendency of the process to create flaws that can lead to sudden failure during use. The root cause of flaw formation in metal AM parts, such as porosity and deformation, is linked to the temperature inside the part during the process, called the thermal history. The thermal history is a function of the process parameters and part design.

Consequently, the first step …

Investigation Of Navigation Systems For Size, Cost, And Mass Constrained Satellites, Omar Awad

USF Tampa Graduate Theses and Dissertations

The feasibility of using radically inexpensive micro-electromechanical system (MEMS) technology for navigation of a nanosatellite is investigated with a focus on attitude estimation. Typically, larger satellites are equipped with star cameras, sun sensors, or Earth horizon sensors for attitude estimation. These sensors can provide very accurate attitude measurements. A nanosatellite is highly size, power, and cost constrained and cannot readily accommodate these sensors. Our mission is to design, build, and operate a radically inexpensive nanosatellite system. While there is no consensus on what constitutes a "radically inexpensive" satellite, our goal is a maximum cost of $10,000 per unit. This precludes …

Experimental Study On Compression And Shear Strength Of Cfrp, Joseph Gentile, Ethan Garber

Discovery Day - Prescott

The increasing use of carbon fiber-reinforced polymer (CFRP) in the aerospace industry requires a better understanding of its damage properties. Many modern aircraft under high loads are utilizing this material for their primary structures due to its high strength to weight ratio. However, CFRPs are sensitive to out-of-plane loading such as low-velocity impact and indentation. These damages can reduce the compressive strength significantly without leaving a visible mark on the surface, which is known as Barely Visible Impact Damage (BVID). The behavior and residual strength of CFRPs after impact damage under compressive loading are still not fully understood. Studies of …

Nonlinear Least Squares 3-D Geolocation Solutions Using Time Differences Of Arrival, Michael V. Bredemann

Mathematics & Statistics ETDs

This thesis uses a geometric approach to derive and solve nonlinear least squares minimization problems to geolocate a signal source in three dimensions using time differences of arrival at multiple sensor locations. There is no restriction on the maximum number of sensors used. Residual errors reach the numerical limits of machine precision. Symmetric sensor orientations are found that prevent closed form solutions of source locations lying within the null space. Maximum uncertainties in relative sensor positions and time difference of arrivals, required to locate a source within a maximum specified error, are found from these results. Examples illustrate potential requirements …

Quantifying Wicking In Functionlized Surfaces, Maureen Winter, Ryan Regan, Alfred Tsubaki, Craig Zuhlke, Dennis Alexander, George Gogos

UCARE: Research Products

Wicking remains the enigmatic key factor in many research areas. From boiling in power plants, to anti-icing on plane wings, to medical instruments, to heat pipes, efficiency and safety depend on how quickly a surface becomes wet. Yet wicking remains difficult to quantify and define as a property of the surface. This experiment strives to measure the wicking property by examining the rate that a liquid can be pulled out of a container. A superhydrophilic surface is placed in contact with the liquid at the bottom of a tube so that the volume flow rate across the surface can be …

Aerodynamics Of Wind Loading On Buildings, Kayla Burch

Honors Theses

A three-dimensional model of a one-story residential home, with an emphasis on the roof style and structure, was modeled using CATIA and then built and tested in the wind tunnel at Western Michigan University. The wind tunnel allowed an airflow over different style roofs to be tested at 100 mile per hour winds, strengths typical for hurricanes and other natural phenomena. The measured results show the lift and drag, along with the pressure gradient and the skin friction over the roofs. The effect of these aerodynamic characteristics of the building due to adding solar panel prototypes were also evaluated. The …

Nytrox As “Drop-In” Replacement For Gaseous Oxygen In Smallsat Hybrid Propulsion Systems, Stephen A. Whitmore

Mechanical and Aerospace Engineering Faculty Publications

A medical grade nitrous oxide (N₂O) and gaseous oxygen (GOX) “Nytrox” blend is investigated as a volumetrically-efficient replacement for GOX in SmallSat-scale hybrid propulsion systems. Combined with 3-D printed acrylonitrile butadiene styrene (ABS), the propellants represent a significantly safer, but superior performing, alternative to environmentally-unsustainable spacecraft propellants like hydrazine. In a manner analogous to the creation of soda-water using dissolved carbon dioxide, Nytrox is created by bubbling GOX under pressure into N₂O until the solution reaches saturation. Oxygen in the ullage dilutes N₂O vapor and increases the required decomposition energy barrier by several orders …

Arizona Hyperloop: The Fifth Mode Of Transportation, Eleanor Pahl, Matthieu Rada

Discovery Day - Prescott

Arizona Hyperloop is a coalition between Embry-Riddle Aeronautical University and Arizona State University students competing in Elon Musk’s annual SpaceX Hyperloop Pod Competition. Hyperloop is the proposed “Fifth Mode of Transportation” - coined “a cross between a Concorde, a rail gun, and an air hockey table.” A hyperloop pod levitates and travels at nearly the speed of sound inside a vacuum tube, which eliminates air resistance. Musk hosts the annual competition to university students to encourage the evolution of urban transportation. The goal is to design, build, and race the fastest prototype pod at SpaceX’s mile-long test track in Hawthorne, …

Aircraft Leading Edge Strakes On Conventional Naca Wings, Anthony Pirone

Discovery Day - Prescott

The prevention of stall on aircraft wings has been a great challenge over the history of airplanes. As the aircraft become more and more complex, it becomes harder to fit high lift devices and leading-edge devices onto high camber, supercritical airfoil aircraft wings. In the fighter jet class of aircraft the obstacle of stall is usually delayed by the implementation of leading-edge root extensions or strakes. Strakes create a tip vortice along the sharp leading edge that transitions over the surface of the wing preventing separation on both the upper and lower surface of the wing allowing the fighter jet …

Sae Aero West Heavy Lift Competition Team - Eaglenautics, Anthony Pirone, Evan Stuart, Jessica Millard, Nathaniel Scott

Discovery Day - Prescott

ERAU’s SAE Aero Design West Competition team encourages students of all majors who have an interest in the design of heavy-lift cargo and passenger aircraft to design, build, and fly a large RC aircraft to meet a new set of regulations each competition year. Since the team, Eaglenautics, was founded in 2017 it has successfully been to competition once in April 2019 in California. The team’s aircraft flew 4 out of 5 flight rounds, passed all technical inspections, and is now on display in ERAU’s Aero-Fab in the AXFAB. The 2020 competition requirements are unique in that the cargo’s weight-to-volume …

Fast Reversible Phase Change Silicon For Visible Active Photonics, Letian Wang, Matthew Eliceiri, Yang Deng, Yoonsoo Rho, Wan Shou, Heng Pan, Jie Yao, Costas P. Grigoropoulos

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Both amorphous and crystalline silicon are ubiquitous materials for electronics, photonics, and microelectromechanical systems. On-demand control of Si crystallinity is crucial for device manufacturing and to overcome the limitations of current phase-change materials (PCM) in active photonics. Fast reversible phase transformation in silicon, however, has never been accomplished due to the notorious challenge of amorphization. It is demonstrated that nanostructured Si can function as a PCM, since it can be reversibly crystallized and amorphized under nanosecond laser irradiation with different pulse energies. Reflection probing on a single nano disk's phase transformations confirms the distinct mechanisms for crystallization and amorphization. The …

Mission Architecture Analysis: Exploring Long-Period Comets From Multiple Staging Orbits, Gabriel Prescinotti Vivan

Masters Theses

Objects that have retained pieces of information about the early Solar System are key to our understanding of its formation and evolutionary history. However, the high delta-V required to reach these objects, such as long-period comets or interstellar objects, makes designing an intercept mission at the time of detection impractical. In this thesis, multiple heliocentric staging orbits are explored to serve as departure positions for future missions, prior to objects’ detections. By utilizing more than one staging orbit concurrently, the set of objects that are reachable is expanded, therefore increasing mission feasibility. Delta-V maps are generated and superimposed; two-impulse burn …

7-Dof Robotic Arm Xy-Plane Translational Stability, Christopher Dean Alkire

Doctoral Dissertations and Master's Theses

Robotic arms are traditionally mounted to rigid structures as they perform tasks. As a result, the arm’s movement would not affect the position of its mount and its operational space that it is performing a task within would remain constant. If a robotic arm were to function in orbit, the motion of the arm would cause it to rotate and translate about its center of mass, which changes as the joints of the arm rotate.

The purpose of this thesis is to focus on the two-dimensional translational effects of an arm operating on a simulated zero-friction surface and provide a …

Interaction Of High Aspect-Ratio Micro-Pillars With Wall Turbulence, Pratik Suhas Deshpande

Doctoral Dissertations and Master's Theses

An experimental study of the interaction between hairy structures modeled as high-aspect ratio micro-pillars (HAMuP) and wall turbulence is presented. Micro-pillars are elastic, hair-like microstructures which have been inspired by naturally occurring examples like lateral line sensors in fish and air flow sensors in bats. The objective of this thesis was two fold: to develop a manufacturing process for consistent production of HAMuP arrays, and to conduct a study focusing on the interaction of HAMuP arrays with wall turbulence. Hotwire anemometry measurements were carried out in two different experimental facilities at three different streamwise locations to describe the interaction between …

Constrained Motion Analysis And Control Of Spacecraft Asteroid Hovering With Formulation Extension In Geometric Mechanics Framework, Wesley Thomas Stackhouse

Doctoral Dissertations and Master's Theses

This thesis studies the constrained motion for a spacecraft hovering over an asteroid, where the Udwadia-Kalaba (UK) formulation is applied for nominal control, and an adaptive controller is developed to account for unknowns in the dynamics. Then, the formulation is extended in the geometric mechanics framework to account for rigid body spacecraft asteroid hovering. Constraints are developed and applied for fully constrained and under-constrained asteroid hovering. The fully constrained solutions provided by the UK fundamental equation are compared to an optimal linear quadratic regulator. An adaptive controller is designed using the UK fundamental equation as a basis in the form …

Trajectory Simulation With Battery Modeling For Electric Powered Unmanned Aerial Vehicles, Ege Konuk

Mechanical & Aerospace Engineering Theses & Dissertations

Fixed wing electric powered unmanned aerial vehicles (UAVs) has been widely adopted for the last decade in a great number of applications. One of the primary advantages to fixed wing versus multi-rotor designs is the efficiency in forward flight with best possible range and endurance capabilities. In electrically powered air vehicles range and endurance are monitored by the State-of-Charge (SOC) of the battery. To understand the capabilities of the battery, discharge experiments can be conducted in lab environments; however, sometimes the results are difficult to integrate in flight simulations.

In this thesis, a trajectory simulation is developed that can estimate …

Thermal Contact Resistance Measurement And Related Uncertainties, Amanda Elizabeth Stark

Mechanical & Aerospace Engineering Theses & Dissertations

Thermal contact resistance is an important parameter in detailed thermal analysis and design of aerospace systems. The ability to determine thermal contact resistance reliably can have a significant impact on the fidelity of thermal models—particularly for space applications. The 2004 NASA Langley Research Center thermal contact resistance test apparatus has been employed to evaluate two methods for inferring estimated interface surface temperatures so that thermal contact resistance can be calculated more accurately. The traditional method of extrapolation is a steady-state approach, while the new method utilizes inverse heat transfer techniques to account for inherent unsteadiness in these quasi-steady-state measurements. The …

An Argument Against Satellite Resiliency: Simplicity In The Face Of Modern Satellite Design, Dax Linville, Robert A. Bettinger

Faculty Publications

The US Air Force and the wider US government rely heavily on space-based capabilities in various orbital regimes to project national security and sovereignty. However, these capabilities are enabled by the design, launch, and operation of satellites produced with a design methodology that favors large, monolithic, and technologically exquisite space systems. Despite the ability for these satellites to provide enduring and resilient capabilities, they suffer from a woefully long acquisition process that debilitates any prospect of rapid satellite reconstitution in the event of a space war.

Through-Thickness Reinforcement And Repair Of Carbon Fiber Based Honeycomb Structures Under Flexure And Tension Of Adhesively Bonded Joints, Aleric Alden Sanders

Mechanical & Aerospace Engineering Theses & Dissertations

Repair and reinforcement of composite honeycomb structures is an area of concern as higher demands are being placed on high strength, lightweight structural materials, such as carbon fiber reinforced plastics and corresponding honeycomb structures. A common issue with these structures is when a delamination in the facesheet may form and spread, leading to a failure scenario. An investigation of adding a through thickness reinforcement (TTR) to these structures at the sample level that undergo four-point-bending, tension, and joining methods is conducted throughout this thesis. The embedding of pultruded carbon fiber rods is found to be an ideal addition to composite …

Rotorcraft Blade Angle Calibration Methods, Brian David Calvert Jr.

Mechanical & Aerospace Engineering Theses & Dissertations

The most vital system of a rotorcraft is the rotor system due to its effects on the overall flight quality of the vehicle. Therefore, it is of importance to be able to accurately determine blade position during flight so that fine adjustments can be made to ensure a safe and efficient flight. In this study, a current calibration method focusing on the pitch, flap, and lead-lag blade angles is analyzed and found to have larger than acceptable error associated with the sensor calibrations. A literature review is conducted which reveals four novel methods that can potentially increase the accuracy of …