Aerospace Engineering Commons^™

Investigation Of Pin Fin Cooling Channels For Applications In Gas Turbines, Royce Fernandes

Doctoral Dissertations and Master's Theses

Gas turbine blades are often cooled using internal cooling channels to prevent failure at temperatures beyond material limitations. Pin fin channels are commonly used on the trailing edge of the blades, where they enhance heat transfer and also provide structural support. This study focuses on the validation of several commercially available RANS turbulence models in CFD, that are used to computationally simulate the flow features inside a pin fin cooling channel. Turbulence models investigates are: Menter’s kω SST, realizable k-ε, and a quadratic formulation of the realizable k-ε model. The geometry investigated is a staggered 8 row pin fin channel. …

The Effect Of Axial Spacing Of Constant And Variable Blockages On The Deflagration-To-Detonation Transition In A Pulse Detonation Engine, Nicole Gagnon

Doctoral Dissertations and Master's Theses

An investigation was conducted into the effects of obstacle spacing on the deflagration-to-detonation transition section length in a pulse detonation engine. Testing was conducted with one hundred and ninety-five different obstacle, and spacing configurations. The configurations included constant, as well as variable spacing between obstacles. The goal of this investigation was to correlate the spacing between obstacles and the blockage ratio of the obstacles with the detonation success and the shortening of the DDT section. The ten cases that achieved the highest percentage of detonations were investigated further to determine the distance needed for the deflagration-to-detonation transition. A 33% blockage …

Optical Tracking And Spectral Characterization Of Cubesats For Operational Missions, Forrest Gasdia

Doctoral Dissertations and Master's Theses

Orbital debris in low Earth orbit is of growing concern to operational satellites from the government and commercial sector. With an uptick in worldwide satellite launches and the growing adoption of the CubeSat standard, the number of small objects in orbit are increasing at a faster pace than ever. As a result, a cascading collision event seems inevitable in the near future.

The United States Strategic Command tracks and determines the orbit of resident space objects using a worldwide network of radar and optical sensors. However, in order to better protect space assets, there has been increased interest in not …

Vibration Analysis Of A Composite Wing Box With Arbitrarily Shaped Spars And Ribs, Rossana R. Fernandes

Doctoral Dissertations and Master's Theses

In this research, the free vibration analysis of composite wing boxes with curvilinear spars and ribs is performed. Modern manufacturing technologies, such as Electron Beam Freeform Fabrication and Friction Stir Welding, have allowed the manufacturing of arbitrarily shaped stiffeners. Curvilinear stiffeners provide flexibility in design as they can assume an infinite number of paths. Curvilinear spars and ribs can in some instances provide a better vibration and static response than their straight counterparts while reducing the overall mass of the structure. An equivalent continuum plate model of a wing box using energy formulations is proposed at the preliminary design stage …

Magneto-Rheological Fluid Device As Artificial Feel Force System On Aircraft Control Stick, Vignesh Manoharan

Doctoral Dissertations and Master's Theses

The conventional feel system in any aircraft occupies large space in the cockpit and has complicated designs. The primary objective of this research is to develop an artificial feel force system that can overcome some drawbacks of the current feel force system. A novel feel system using magneto-rheological (MR) fluid is constructed to precisely control the shear stress under the magnetic field. To validate the functionality of the MR artificial feel system, the final system is fabricated and multiple tests are performed to acquire force-velocity characteristics that are compared to the mathematical model derived. In addition, the reference model of …

A Radial Basis Function Method For Solving Optimal Control Problems., Hossein Mirinejad

Electronic Theses and Dissertations

This work presents two direct methods based on the radial basis function (RBF) interpolation and arbitrary discretization for solving continuous-time optimal control problems: RBF Collocation Method and RBF-Galerkin Method. Both methods take advantage of choosing any global RBF as the interpolant function and any arbitrary points (meshless or on a mesh) as the discretization points. The first approach is called the RBF collocation method, in which states and controls are parameterized using a global RBF, and constraints are satisfied at arbitrary discrete nodes (collocation points) to convert the continuous-time optimal control problem to a nonlinear programming (NLP) problem. The …

Experimental, Numerical, And Analytical Slosh Dynamics Of Water And Liquid Nitrogen In A Spherical Tank, Jedediah Morse Storey

Theses and Dissertations

Understanding, predicting, and controlling fluid slosh dynamics is critical to safety and improving performance of space missions when a significant percentage of the spacecraft’s mass is a liquid. Computational fluid dynamics simulations can be used to predict the dynamics of slosh, but these programs require extensive validation. Many experimental and numerical studies of water slosh have been conducted. However, slosh data for cryogenic liquids is lacking. Water and cryogenic liquid nitrogen are used in various ground-based tests with a spherical tank to characterize damping, slosh mode frequencies, and slosh forces. A single ring baffle is installed in the tank for …

Path Following By A Quadrotor Using Virtual Target Pursuit Guidance, Abhishek Manjunath

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Missile guidance laws have been solely developed to follow and intercept a target thereby destroying or damaging it. In this research, the primary objective is to modify and adopt a missile guidance law to be used on a quadrotor to follow a virtual target. The target is termed 'virtual' as it only exists mathematically in the form of equations. The goal is to have the quadrotor successfully following the predefined path (described by the target) while maintaining a fixed distance from the virtual target. To ensure viability and assess performance, a detailed comparison with another path following law is made.

Quadrotor Uav Path Following Using Trajectory Shaping, Parwinder Singh Mehrok

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The propose of this research is to develop a path following control law known as Trajectory Shaping. The approach is to develop a three- dimensional (3D) version of it from an existing two-dimensional (2D) model. Apart from research on this 3D control law, a multirotor unmanned aerial vehicle (UAV) platform, having four rotors and known as quadrotor is designed from the ground up for validating the concept of path following. Several pre-defined paths like the circle and figure-eight trajectories are used to apply the newly developed version of this control law. The existing 2D concept of Trajectory Shaping guidance …

Microalgae Sorption Of Ten Individual Heavy Metals And Their Effects On Growth And Lipid Accumulation, Eric M. Torres

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study is to determine the potential microalgae have for being a heavy metal remediation tool. Heavy metals are naturally occurring elements that can be found inside the earth or on its surface. Typically, heavy metals are found naturally at low concentrations. However, through human activities, heavy metals are continually making their way to the surface and being concentrated. This happens largely through mining and manufacturing operations. For example, NiCd batteries produce waste containing nickel and cadmium, and paper manufacturing produces waste containing high levels of lead. As underdeveloped nations continue to industrialize and the world population …

Development Of A Three-Dimensional High-Order Strand-Grids Approach, Oisin Tong

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The strand-Cartesian grid approach is a unique method of generating and computing fluid dynamic simulations. The strand-Cartesian approach provides highly desirable qualities of fully-automatic grid generation and high accuracy. This work focuses on development of a high-accuracy methodology (high-order scheme) on strand grids for two and three dimensions.

In this work, the high-order scheme is extended to high-Reynolds number computations in both two and three dimensions with the Spalart-Allmaras turbulence model and the Menter SST turbulence model. In addition, a simple limiter is explored to allow the high-order scheme to accurately predict discontinuous flows.

Extensive verification and validation is conducted …

Effects Of Radiation Heating On Additively Printed Hybrid Fuel Grain Oxidizer-To-Fuel Ratio Shift, Stephen L. Merkley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis examined the hypothesis that radiative heat transfer in small-scale printed-fuel hybrid rocket motors is responsible for the observed decreasing oxidizer-to-fuel (O/F) ratio shift. The magnitude of the radiation term was negligible for the motor sizes and types of propellants that have been previously tested, but was reintroduced in this study. To prove this hypothesis, a detailed enthalpy balance model was developed and tested using experimental fuel regression rate data obtained from a variety of motor scales using additively-manufactured acrylonitrile butadiene styrene (ABS) fuel grains.

High Power Rocket Design Report, Laura E. Calcara, Monica Fernandez, Chris Green, Trent Hosokawa

Honors Thesis

Highpower rockets are extremely sensitive systems that require precise planning, testing, and analysis in order to yield accurate results. Under the guidance of project advisor, Dan Larson, a highpower rocket was designed and built to reach an apogee of 3000 feet. Additionally, means of dual deployment was used in order to aid in the safe descent and recovery of the rocket. In order to meet this expectation, two parachutes were used in conjunction with black powder ejection charges. Compliance with the safety standards of NAR and NFPA was met for the ejection system used in dual deployment. To ensure that …

Phased Array Antenna Investigation For Cubesat Size Satellites, Kien Dang

Morehead State Theses and Dissertations

A Thesis Presented to the Faculty of the College of Science Morehead State University in Partial Fulfillment of the Requirements for the Degree Master of Science by Kien Dang on April 18, 2016.

Software Defined Multi-Spectral Imaging For Arctic Sensor Networks, Sam B. Siewert, Matthew Demi Vis, Ryan Claus, Vivek Angoth, Karthikeyan Mani, Kenrick Mock, Surjith B. Singh, Saurav Srivistava, Chris Wagner

Publications

Availability of off-the-shelf infrared sensors combined with high definition visible cameras has made possible the construction of a Software Defined Multi-Spectral Imager (SDMSI) combining long-wave, near-infrared and visible imaging. The SDMSI requires a real-time embedded processor to fuse images and to create real-time depth maps for opportunistic uplink in sensor networks. Researchers at Embry Riddle Aeronautical University working with University of Alaska Anchorage at the Arctic Domain Awareness Center and the University of Colorado Boulder have built several versions of a low-cost drop-in-place SDMSI to test alternatives for power efficient image fusion. The SDMSI is intended for use in field …

The Design Of A Racing Simulator: A Three-Phase User Testing Approach, Jakob E. Rouleau, Eric J. Wach

Human Factors and Applied Psychology Student Conference

No abstract provided.

Ergonomics In Space Flight – Past, Present, & Future, Robert Consolo

Human Factors and Applied Psychology Student Conference

From the days of “The Rocket Men” to the uprising of SpaceX, spaceflight has always inspired awe in humanity. If you examine the men that were apart of those first missions, you will find that they were not only the most capable, but won the genetic lottery to become this nations first astronauts. Looking to the times of Mercury, you see the extreme constraints that potential astronaut candidates had to meet in order to go to space. Aside from the rigorous medical testing, potential candidates also had to meet strict height and weight requirements. Early candidates could not be taller …

Designing A Mobile Space Habitat Analog, Victor Kitmanyen, Matthew Burkhard, Timothy Disher

Human Factors and Applied Psychology Student Conference

No abstract provided.

Design Of A Master Cutdown Payload For High-Altitude Balloon Applications, Bradley Henderson

Research Horizons Day Posters

No abstract provided.

The Effect Of Golden Pothos In Reducing The Level Of Colatile Organic Compounds In A Simulated Spacecraft Cabin, Matthew Ursprung

Research Horizons Day Posters

No abstract provided.