Aerospace Engineering Commons^™

Flying Qualities Built-In-Test For Unmanned Aerial Systems, Alton Pak-Hin Chiu

Master's Theses

This paper presents a flying qualities built-in-test for UAS application with the scope limited to the longitudinal axis. A doublet input waveform excites the AV and both α and q are used by EUDKF to estimate the A and B matrices which are short period approximations of the system. ζ, ω, GM, PM, observability, and controllability are calculated to determine flying qualities with the results displayed to the AVO in a color-coded, easy to interpret display.

While SID algorithms have been flying in vehicles with adaptive control schemes, vehicles with other schemes (such as classical feedback) lack this built-in self …

Activity Node Based Flight Software As A Benefit To Systems Engineering, Eugene Daniel Lewis

Master's Theses

This report discusses one application of a flight software design for a spacecraft in which the software executes from a database that can be managed by systems engineering. This report gives an overview of how such a software design can be developed and implemented. It also discusses why this approach is beneficial to the systems engineering program.

Cubesat Mission Planning Toolbox, Brian Castello

Master's Theses

We are in an era of massive spending cuts in educational institutions, aerospace companies and governmental entities. Educational institutions are pursuing more training for less money, aerospace companies are reducing the cost of gaining ight heritage and the government is cutting budgets and their response times. Organizations are accomplishing this improved efficiency by moving away from large-scale satellite projects and developing pico and nanosatellites following the CubeSat specifications. One of the major challenges of developing satellites to the standard CubeSat mission requirements is meeting the exceedingly tight power, data and communication constraints.

A MATLAB toolbox was created to assist the …

Feasibility Study Into The Use Of 3d Printed Materials In Cubesat Flight Missions, Daniel Fluitt

Master's Theses

The CubeSat Program has provided access to space for many universities, private companies, and government institutions primarily due to the low cost of CubeSat satellite development. While these costs are orders of magnitude lower than similarly capable nano-satellite missions, they are still outside of the budgetary constraints of many potential developers including university and high school clubs. Using 3D printed plastics in the production of CubeSat structures and mechanisms presents a large cost savings opportunity that will allow these institutions to participate in the development of these satellites, expanding the educational and scientific impact of the CubeSat Program.

Five rapid …

Implementation Of A ¼ Inch Hollow Cathode Into A Miniature Xenon Ion Thruster (Mixi), David Wayne Knapp

Master's Theses

Over the last decade, miniature ion thruster development has remained an active area of research do to its low power, low thrust, and high efficiency, however, due to several technical issues; a flight level miniature ion thruster has proved elusive. This thesis covers the design, fabrication, assembly, and test of an altered version of the Miniature Xenon Ion thruster (MiXI), originally developed by lead engineer Dr. Richard Wirz, at the California Institute of Technology (Caltech). In collaboration with Dr. Wirz, MiXI-CP-V3 was developed at Cal Poly San Luis Obispo with the goal of implementing of a ¼ inch hollow cathode …

An Investigation Of Damage Arrestment Devices On Carbon Fiber Sandwich Specimens Under Dynamic Loading, Gabriel Sabino Sanchez

Master's Theses

This research studies the effects of a damage arrestment device embedded between a carbon fiber facesheet and foam core to find whether there is an increase in the structural integrity of the sandwich composites. Experimental and theoretical finite element analyses are implemented for two different composite sandwich geometries; plates and beams. Each structure consisted of the same loading criteria and was restricted to the same vibration fixture during the experiment. An accelerometer was placed on the composite plate to record the amplitude and the natural frequencies of the composite structure. Each composite specimen is then fixed to the surface of …

Hapss, Hybrid Aircraft Propulsion System Synthesis, Michael W. Green

Master's Theses

Hybrid Aircraft Propulsion System Synthesis (HAPSS) is a computer program that sizes and analyzes pure-series hybrid electric propulsion systems for aircraft. The development of this program began during a NASA SBIR contract, in conjunction with Empirical Systems Aerospace (ESAero), with the creation of a propulsion fan design tool. Since the completion of this contract in July 2010, the HAPSS program has been expanded to combine the many aspects of a hybrid propulsion system such as the propulsive fans, electric motors, generators, and controllers, and the internal combustion engines.

This thesis describes the benefits and drawbacks of aircraft hybrid propulsion systems …

Modal Analysis Of Composite Structures With Damping Material, Kellie Michelle Tremaine

Master's Theses

The purpose of this study is to develop an analytical solution for modal analysis of actively damped orthotropic composite plates in bending and to verify it with experimental analysis.

The analytical modal analysis solution for composite plate dynamics is derived using Euler theory. This analysis applies to structures with orthotropic lamina of uniform material properties at any lamination angle. The bending-extensional coupling can be neglected for plates that are symmetric or approximately symmetric, which allows an exact solution for natural frequency and mode shape to be obtained. An exact solution can be found for natural vibration and in general.

The …

Day/Night Band Imager For A Cubesat, Eric Stanton

Electrical Engineering

Day/Night Band (DNB) earth sensing and meteorological systems like the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) provide visible wavelength imagery 24 hours a day that is used primarily for cloud imaging in support of weather forecasting. This paper describes a compact push-broom imager that meets low light imaging requirements for DMSP OLS and the NOAA/NASA Joint Polar Satellite System (JPSS) as documented in the Integrated Operational Requirements Document [1] (IORD) including the imager design, system level concepts of operation for data collection, radiometric and spatial calibration, and data transmission to Earth. This small, lightweight imager complies with …

An Experimental Investigation Of Glare And Restructured Fiber Metal Laminates, Adelina Vanessa Benedict

Doctoral Dissertations and Master's Theses

Fiber Metal Laminates (FMLs) are a group of materials fabricated by bonding glass/epoxy layers within metal layers. This class of materials can provide good mechanical properties, as well as weight savings. An FML known as Glass Laminate Aluminum Reinforced Epoxy (GLARE) was studied. An experimental investigation comprising of microscopy and tensile testing was carried out using different grades of GLARE. Microscopy revealed the construction details of GLARE, while tensile testing provided means of measuring and analyzing its stress-strain responses. Next, different metal surface pretreatment methods were explored. These included sandblasting, Phosphoric Acid Anodizing (PAA), and AC-130 Sol-Gel treatment. Woven S-2 …

Analysis And Testing Of Heat Transfer Through Honeycomb Panels, Daniel D. Nguyen

Aerospace Engineering

This project attempts to simulate accurately the thermal conductivity of honeycomb panels in the normal direction. Due to the large empty space of the honeycomb core, the thermal radiation mode of heat transfer was modeled along with conduction. Using Newton’s Method to solve for a steady state model of heat moving through the honeycomb panel, the theoretical effective thermal conduction of the honeycomb panel was found, ranging from 1.03 to 1.07 Q/m/K for a heat input of 2.5 W to 11.8 W. An experimental model was designed to test the theoretical results, using a cold plate and a heat plate …

Design Of Orbital Maneuvers With Aeroassisted Cubesatellites, Stephanie Clark

Graduate Theses and Dissertations

Recent advances within the field of cube satellite technology has allowed for the possible development of a maneuver that utilizes a satellite's Low Earth Orbit (LEO) and increased atmospheric density to effectively use lift and drag to implement a noncoplanar orbital maneuver. Noncoplanar maneuvers typically require large quantities of propellant due to the large delta-v that is required. However, similar maneuvers using perturbing forces require little or no propellant to create the delta-v required. This research reported here studied on the effects of lift on orbital changes, those of noncoplanar types in particular, for small satellites without orbital maneuvering thrusters. …

Evaluation Of Turbulence Variable Distributions For Incompressible Fully Rough Pipe Flows, Emilie B. Fowler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The specific turbulent kinetic energy, root-mean-square fluctuating vorticity, and mean-vortexwavelength distributions are presented for fully rough pipe flow. The distributions of these turbulence variables are obtained from a proposed turbulence model. Many of the turbulence models commonly used for computational fluid dynamics are based on an analogy between molecular and turbulent transport. However, traditional k-ε and k-ω models fail to exhibit proper dependence on the molecular viscosity. Based on a rigorous application of the Boussinesq’s hypothesis, Phillips proposed a vorticity-based transport equation for the turbulent kinetic energy. The foundation for this vorticity-based transport equation is presented. In future development of …

Reduction Of Solid-Solid Thermal Boundary Resistance By Inserting An Interlayer, Zhi Liang, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An Effective Method is Proposed to Greatly Improve the Thermal Transport Across the Interface between Two Solids with Dissimilar Phonon Spectra. If the Two Solids Have Similar Crystal Structure and Lattice Constant, It is Predicted from the Molecular Dynamics Modeling that an over 50% Reduction of the Thermal Boundary Resistance Can Be Achieved by Inserting a 3-Unit-Cell-Thick Interlayer Whose Debye Temperature is Approximately the Square Root of the Product of the Debye Temperatures of the Two Solids. on the Other Hand, If the Two Solids Have a Large Difference in Lattice Constant, It is Found the Interfacial Atomic Restructuring Plays …

Novel Heavy Duty Engine Concept For Operation Dual Fuel H 2-Nh3, Alberto A. Boretti

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A prior paper has presented a novel design of a heavy-duty truck engine fueled with H2. in this design, the customary in-cylinder Diesel injector and glow plug are replaced with a main chamber fuel injector and a jet ignition pre-chamber. the jet ignition pre-chamber is a small volume that is connected to the in-cylinder through calibrated orifices accommodating another fuel injector and a glow or a spark plug that controls the start of combustion. This design permits to operate the engine in four different modes: traditional compression ignition (CI), diffusion, Diesel-like (M1); mixed gasoline/Diesel-like (M2); traditional spark ignition (SI), premixed, …

Sun-Synchronous Orbit Slot Architecture Analysis And Development, Eric Watson

Master's Theses

Space debris growth and an influx in space traffic will create a need for increased space traffic management. Due to orbital population density and likely future growth, the implementation of a slot architecture to Sun-synchronous orbit is considered in order to mitigate conjunctions among active satellites. This paper furthers work done in Sun-synchronous orbit slot architecture design and focuses on two main aspects. First, an in-depth relative motion analysis of satellites with respect to their assigned slots is presented. Then, a method for developing a slot architecture from a specific set of user defined inputs is derived.

An Inverse Design Method For Supersonic Airfoils, Steven Edward Skare

Master's Theses

Airfoil design is one of the most important aspects of aircraft design. Slight changes in airfoil geometry can lead to significant changes in a wide variety of aircraft performance metrics. Inverse design methods offer an efficient alternative to standard direct methods. The key to this design problem is to derive a direct relationship between changes in airfoil geometry and changes in pressure or velocity distributions. This relationship is then used to modify an initial airfoil and its pressure distribution to match a target pressure distribution, which is specified by design parameters. At this point, the engineer now has a final …

Primary And Secondary Flow Interactions In The Mixing Duct Of A 2-D Planer Air Augmented Rocket, Martin Roy Popish

Master's Theses

Experiments were conducted on the Cal Poly air augmented rocket (AAR) in order to characterize two-dimensional flowfield phenomenon occurring in the mixing duct. The testing utilized a direct connect system where high pressure nitrogen is fed into the combustion chamber, to form a primary flow. The high pressure nitrogen is then expanded through a nozzle, with an area ratio of 22 and an exit area of 0.75 in², up to Mach 4.3. Secondary air is entrained from a plenum chamber which is used to create a lower stagnation pressure for the secondary flow. The two flows mix in …

Spacecraft And Propulsion Technician Error, Daniel Clyde Schultz

Doctoral Dissertations and Master's Theses

Commercial aviation and commercial space similarly launch, fly, and land passenger vehicles. Unlike aviation, the U.S. government has not established maintenance policies for commercial space. This study conducted a mixed methods review of 610 U.S. space launches from 1984 through 2011, which included 31 failures. An analysis of the failure causal factors showed that human error accounted for 76% of those failures, which included workmanship error accounting for 29% of the failures. With the imminent future of commercial space travel, the increased potential for the loss of human life demands that changes be made to the standardized procedures, training, and …

Spacecraft Collision Probability Estimation For Rendezvous And Proximity Operations, Michael R. Phillips

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An increasing number of missions require spacecraft to fly in close proximity. Despite the technological advances that have made these types of missions increasingly possible there remains a limit to how accurately the trajectory of a spacecraft can be predicted. As such, one of the main risks to spacecraft in close proximity is the threat of a collision. Many methods exist for computing the probability of collision between spacecraft. These methods incorporate the uncertainty in predicting the spacecrafts motion when computing an estimate. The accuracy and required computation time of these methods very greatly. A poor estimate of collision risk …