Aerospace Engineering Commons^™

Residual Strength Estimation Of Degraded Bonded Joints Based On Non-Destructive Evaluations, Guilherme Garcia Momm

Theses and Dissertations

Pioneer designers acknowledged structural bonding advantages over other joining methods, sparking many aerospace applications. Nonetheless, durability issues, weak bonds, and the inability to non-destructively interrogate bond quality after-the-fact hindered widespread bonding use. These challenges also contributed to several aircraft accidents, fostering extensive related research. Firstly, we examined the bonding operational history in aviation. The challenge to simulate or experimentally reproduce bonded joints’ long-term behavior under real-life conditions magnifies the value of in-service data. Since 1944 the International Civil Aviation Organization has recommended investigating aircraft incidents/accidents. Among numerous investigation reports publicly available, we identified 73 bond-related occurrences involving type-certified aircraft registered …

Computer Vision Of Analog Gauges As An Alternative To Digital Flight Test Instrumentation, Michael William James

Theses and Dissertations

Currently, there are a couple of options to gather stick force data from flight test aircraft. Either the aircraft is instrumented with costly piezoelectric force sensors and recorders integrated into the aircraft stick, or the test pilot must use a traditional analog stick force gauge with a pointer and telltale. The conventional stick force gauge works well when the pilot has the mental and physical bandwidth to read and remember, or record, the stick force values throughout the maneuver but does not suffice when in a task saturated, high g force maneuver such as the windup turn. This project proposes …

Practical Applications Of Pressure-Fed Lox/Ch4 Rocket Engines, James Susen Parks

Open Access Theses & Dissertations

The University of Texas at El Paso Aerospace Center is working on a family of LOX/CH4 pressure-fed rocket engines. The applications of a pressure-fed rocket engine include orbital launch vehicles and lunar ascent and descent vehicles. This dissertation focuses on the application of the CROME LOX/CH4 engines under development at UTEP. The dissertation contains three chapters on orbital launch vehicles and a fourth chapter on lunar descent/ascent vehicles. The first two chapters look at pressure-fed LOX/CH4 orbital launch vehicle design compared to an electric pump fed and a gas generator vehicle. The third chapter looks at the sensitivities in the …

A Study Of Wings With Constant And Variable Sweep For Aerodynamic Efficiency In Inviscid Flow, Bruno Moorthamers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wing sweep has been studied by industry and academia since the pioneering days of aviation for both high-speed and low-speed applications. In transonic and supersonic flight regimes it serves to delay the onset of compressibility effects and decrease wave drag. In subsonic conditions, flying wing designs sweep back the main lifting surface in such a way that it can be used for longitudinal stability and control, to allow for the elimination of a traditional empenage. This is desirable because it can decrease the aerodynamic drag. Sweep can also be seen in nature in the wings of birds and fins of …

Optimal Relative Path Planning For Constrained Stochastic Space Systems, Nathan Bohus Stastny

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rendezvous and proximity operations for automated spacecraft systems requires advanced path planning techniques that are capable of generating optimal paths. Real-world constraints, such as sensor noise and actuator errors, complicate the planning process. Operations also require flight safety considerations in order to prevent the spacecraft from potentially colliding with the associated companion spacecraft. This work proposes a new, ground-based trajectory planning approach that seeks an optimal trajectory while meeting all mission constraints and accounting for vehicle performance and safety requirements. This approach uses a closed-loop linear covariance simulation of the relative trajectory coupled with a genetic algorithm to determine fuel …

Rotating Detonation Rocket Engine Fluidic Diode Injector Studies, Allison Brooke Lentz

Honors Capstone Projects and Theses

No abstract provided.

Computational Plasma Modeling For Characterization Of An Atmospheric Pressure Plasma Jet, Declan George Brick

Honors Capstone Projects and Theses

No abstract provided.

Honor Capstone Lunar Logistics Study, Owen Bradley Cox

Honors Capstone Projects and Theses

No abstract provided.

A Primer For Designing A Small Spacecraft Mission Operations Architecture, Joseph M. A. Feliciano

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 Joseph M. A. Feliciano on April 28, 2022.

Design And Analysis Of A Pitch Controller For An Unstable Aircraft Using A Linear Quadratic Regulator, Marco Antonio Garcia

Honors Capstone Projects and Theses

No abstract provided.

Early Warning Reentry System Comprising High Efficiency Module For Determining Spacecraft Reentry Time, Robert A. Bettinger

AFIT Patents

The present invention relates to an early warning reentry system comprising a high efficiency module for determining spacecraft reentry time and a highly efficient method for determining spacecraft reentry time. The method permits more accurate, earlier spacecraft reentry time determinations using publicly available trajectory information without the need for accounting for the actual design configuration of the spacecraft in question. Thus, a module for making such determinations can easily and inexpensively be added to an early warning reentry system.

Characterizing And Predicting Human Visual Perception Of Unmanned Aerial Vehicle Gestures, Paul Fletcher

School of Computing: Dissertations, Theses, and Student Research

Unmanned Aerial Vehicles (UAVs) are being used in public domains and hazardous environments where effective communication strategies are critical. UAV gesture techniques have been shown to communicate meaning to human observers and may be ideal in contexts that require lightweight systems such as unmanned aerial flight, however, this work may be limited to an idealized range of viewer perspectives. As gesture is a visual communication technique it is necessary to consider how the perception of a robot gesture may suffer from obfuscation or self-occlusion from some viewpoints. This thesis presents the results of three online user-studies that examine participants’ ability …

Direct Numerical Simulation Of Hypersonic Turbulent Boundary Layers: Effect Of Spatial Evolution And Reynolds Number, Junji Huang, Lian Duan, Meelan M. Choudhari

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Direct numerical simulations (DNS) are performed to investigate the spatial evolution of flat-plate zero-pressure-gradient turbulent boundary layers over long streamwise domains (Formula Presented, with Formula Presented the inflow boundary-layer thickness) at three different Mach numbers, Formula Presented, Formula Presented and Formula Presented, with the surface temperatures ranging from Quasi adiabatic to highly cooled conditions. The settlement of turbulence statistics into a fully developed equilibrium state of the turbulent boundary layer has been carefully monitored, either based on the satisfaction of the von Kármán integral equation or by comparing runs with different inflow turbulence generation techniques. The generated DNS database is …

Development Of A Bio-Inspired Artificial Butterfly Vehicle, Thomas Payne Clark

Honors Capstone Projects and Theses

No abstract provided.

Computational Analysis Of The Effects Of Scarfed Nozzle Variations On Jet Plumes, Andrew J. La Sorsa

ONU Student Research Colloquium

A computational fluid dynamics analysis investigating the variation of effects on nozzles with non-orthogonal exit planes, known as scarfing, was performed. The steady Reynolds-averaged Navier-Stokes model, coupled with the Spalart-Allmaras turbulence model, was used to simulate and compare plume development and characteristics using various scarfing geometries at variable inlet conditions. The jet plume cross-section is significantly affected for overexpanded conditions, while retaining the nozzle exit shape for underexpanded conditions, although slight peaks (bifurcation) do occur at the centerline. The same observations occur when slightly changing the angle of scarf. However, inverting the overall geometry of the diverging portion of the …

Effects Of Vortex Generator Placement On A Horizontal Axis Wind Turbine Blade, Dagan Sorensen

ONU Student Research Colloquium

Vortex generators are commonly used devices to control the flow over an airfoil or other surface. In this paper the effect of differing placements of vortex generators on a wind turbine airfoil, compared to an airfoil without vortex generators, were simulated using computational fluid dynamics(CFD). It was shown that, in some instances, the application of vortex generators effectively controlled the flow over the airfoil to increase the power produced by the wind turbine. According to the CFD results, the application of vortex generators at an angle increased the lift produced, as well as delaying the separation of the boundary layer.

Computational Comparison Of Dual Bell, Expansion-Deflection, And Aerospike Nozzles, Manuel R. Abadie Ardon

Honors College Theses

In the search for a Single-Stage-to-Orbit rocket, Altitude Compensating Nozzles concepts (ACNs) have been proposed since the 1950s, but research has stalled despite the modern analysis tools available. These nozzle concepts offer optimum performance at two or more altitude settings. This research chose three of these concepts, these being the Dual Bell, Expansion-Deflection, and Aerospike, which were designed and analyzed at various pressure ratios (NPR=10,15,30,36,30,45) using Computational Fluid Dynamics (CFD) software FLUENT. Simulations generated pressure distributions along the nozzle wall, which allowed to calculate data values such as thrust coefficients. Nozzle efficiency is calculated from this data and used to …

A Review Of Avian-Inspired Morphing For Uav Flight Control, Christina Harvey, Lawren L. Gamble, Christian R. Bolander, Douglas F. Hunsaker, James J. Joo, Daniel J. Inman

Mechanical and Aerospace Engineering Faculty Publications

The impressive maneuverability demonstrated by birds has so far eluded comparably sized uncrewed aerial vehicles (UAVs). Modern studies have shown that birds’ ability to change the shape of their wings and tail in flight, known as morphing, allows birds to actively control their longitudinal and lateral flight characteristics. These advances in our understanding of avian flight paired with advances in UAV manufacturing capabilities and applications has, in part, led to a growing field of researchers studying and developing avian-inspired morphing aircraft. Because avian-inspired morphing bridges at least two distinct fields (biology and engineering), it becomes challenging to compare and contrast …

Design, Optimization, And Construction Of Flexure, Optical, Damping, And Leveling Systems For Electric Propulsion Thrust Stand, Logan Hefferan

Honors Theses

An Thrust Stand is a device that uses the basic principles of torsion and displace­ment to experimentally measure and calculate the thrust generated by an Electric Propulsion (EP) Thruster. Western Michigan University is host to three organiza­tions that work with electric propulsion thrusters currently without a way of ob­taining direct experimental thrust data. For this Senior Design Project, the flexure, optical sensing, damping and leveling systems for a thrust stand originally designed by Hannah Watts in her WMU Honors Thesis: Design of A Thrust Stand for Elec­tric Propulsion [13] will be constructed. The four subsystems will be redesigned, optimized, and …

Novel 360-Degree Camera, Ian Gauger, Andrew Kurtz, Zakariya Niazi

Frameless

Circle Optics is developing novel technology for low-parallax, real time, panoramic image capture using an integrated array of multiple adjacent polygonal-edged cameras. This technology can be optimized and deployed for a variety of markets, including cinematic VR. Circle Optics’ existing prototype, Hydra Alpha, will be demonstrated.

Novel Thermal Coating For High-Speed Airplanes, Abinash Satapathy, Lakshay Battu, Liam Watson, Nazanin Rajabi

Symposium of Student Scholars

In comparison to various other materials, Carbon Fiber, specifically Carbon Fiber Reinforced Polymers (CFRP), is pre-eminent amongst other materials for use on aeronautical systems. Due to its high specific strength (strength-to-weight ratio), CFRP is prominent for carrying heavy loads while maintaining a lightweight build. However, when influenced by heat resulting from air resistance, CFRP is known to undergo serious degradation that would significantly decrease the effectiveness of the polymers. To prevent this degradation and maintain the strength of the CFRP, thermal protective layers (TPLs) are designed to shield the CFRP from heat exposure. This research is focused on the examination …

Advancements Of Autonomous Applications, Jessica Massey, Jeremy Evert

Student Research

This material is based upon work supported by the National Aeronautics and Space Administration under Grant Agreement No. 80NSSC20M0114 issued through Oklahoma Space Grant Consortium. This research is in support of the Fire Dawgs competition team for this year’s SpeedFest competition at Oklahoma State University. This NASA OK Space Grant Consortium funded competition team will compete in the Charlie Class, where an autonomous vehicle will navigate a course and put out a fire.

Robots and self-driving vehicles are useful, especially for hazardous jobs, such as firefighting. The use of high-tech sensing technology is a small part of how self-driving vehicles …

A Brief Literature Review For Machine Learning In Autonomous Robotic Navigation, Jake Biddy, Jeremy Evert

Student Research

Machine learning is becoming very popular in many technological aspects worldwide, including robotic applications. One of the unique aspects of using machine learning in robotics is that it no longer requires the user to program every situation. The robotic application will be able to learn and adapt from its mistakes. In most situations, robotics using machine learning is designed to fulfill a task better than a human could, and with the machine learning aspect, it can function at the highest level of efficiency and quality. However, creating a machine learning program requires extensive coding and programming knowledge that can be …

Vertically Air Lifted High Altitude Light Launch Apparatus (Valhalla), Benjamin E. Chaback, Ethan L. Deweese, Avery Evans, Alyssa Hodum

Beyond: Undergraduate Research Journal

Project VALHALLA aims to get collegiate level rockets to reach higher altitudes by providing a launch platform that shall allow them to be launched from 100,000 ft. This shall allow researchers to pass ninety percent of Earth's dense atmosphere when launching their rockets and shall allow for research at altitude. VALHALLA’s design consists of using multiple high-altitude balloons arranged around a launch platform to reach the target altitude with the rocket. The project shall consist of the following subsystems: policy, structure and design, helium recovery system, and electronics. The policy team shall be responsible for ensuring that this platform conforms …

Wildfire Updrafts And Downdrafts Effects Of Aerial Vehicles Flight Mechanics, Connor Flynn

Honors Capstone Projects and Theses

No abstract provided.

Newton Versus Bernoulli: How Is Lift Created?, Nihad E. Daidzic

Aviation Department Publications

FAA Safety Seminar (GL15109627) held on Saturday, April 2, 2022.

Cfd Simulation Of Varying Fuel Jet Placement Of Mach 2 Flow (Paper), Sara Broad

Honors Capstone Projects

Supersonic flow is a concept that has been researched heavily for the past twenty years. It has many applications, with the most notable one being for the defense industry. This project specifically is based off a model that is being currently used for Air Force research. With supersonic flow, where the Mach number is larger than one, there has been continual research specifically on flameholders. Flameholders involve the discussion of the mixing, ignition, and combustion of the fuel that is released into the lower cavity of the scramjet. There is a current standard for the placement of fuel jets, but …

Investigation Of The Low-Temperature Combustion Phenomena Of A Fischer-Tropsch Synthetic Aerospace Fuel In A Constant Volume Combustion Chamber For Greenhouse Gas Reduction, Lily H. Parker

Honors College Theses

Greenhouse gases (GHG) have a harmful effect on our environment as they trap heat in the atmosphere accelerating climate change. As such, the Federal Aviation Administration’s 2025 strategic plan to reduce GHG emissions from air transportation. This call to action for a more environmentally friendly option highlights the importance of synthetic fuels as they are more sustainable compared to traditional fossil fuels. An investigation was conducted into the thermal-physical properties of Synthetic Fischer-Tropsch (F-T) Sustainable Aviation Fuels (SAF) and the Low Temperature Combustion (LTC). LTC is composed of the Low Temperature Heat Release (LTHR) and Negative Temperature Coefficient (NTC) region, …

Understanding The Nonlinear Dynamics Governing Vertical-Lift Vehicles With Variable-Speed, Fixed Rotors, Stephanie Vavra, Micah Busboom, Aleea Stanford, Keegan Moore

UNL Student Research Days Posters, Undergraduate

Problem: Traffic significantly limits travel in urban areas. • The NASA Urban Air Mobility Project is developing an air taxi as an alternative mean of transportation (Fig. 1).

Challenge: Operating rotors at different frequencies may cause the cabin to vibrate at high amplitudes. Such effects are currently unknown.

Objective: Understand the effect of variable speed rotors on passenger comfort.

From the reduced-order modeling simulations, it can be assumed that counteracting the rotor speed in-balances can reduce the displacement and vibrations experienced at the center of the wing. In other words, should a rotor not maintain its optimal operation speed, reducing …

Vertical Take-Off And Landing Control Via Dual-Quaternions And Sliding Mode, Joshua Sonderegger

Doctoral Dissertations and Master's Theses

The landing and reusability of space vehicles is one of the driving forces into renewed interest in space utilization. For missions to planetary surfaces, this soft landing has been most commonly accomplished with parachutes. However, in spite of their simplicity, they are susceptible to parachute drift. This parachute drift makes it very difficult to predict where the vehicle will land, especially in a dense and windy atmosphere such as Earth. Instead, recent focus has been put into developing a powered landing through gimbaled thrust. This gimbaled thrust output is dependent on robust path planning and controls algorithms. Being able to …