Digital Commons Network^™

Fatigue Behavior Of A Sic/Sic Composite At 1000⁰C In Air And In Steam, Michael W. Knauf

Theses and Dissertations

Tension-tension fatigue behavior of a prototype Silicon Carbide/Silicon Carbide (SiC/SiC) ceramic matrix composite (CMC) material was investigated at 1000°C in laboratory air and in steam environments. The material consists of a SiC matrix reinforced with CG NICALON™ fibers woven in an eight harness satin weave (8HSW) and coated with a BN/SiC dual-layer interphase. The composite was manufactured by a Polymer Infiltration and Pyrolysis (PIP) process. A seal coat of SiC and elemental boron was applied to the test specimens after machining. The tensile stress-strain behavior was investigated and the tensile properties were measured at 1000°C. Tension-tension fatigue behavior was studied …

Navigation With Limited Prior Information Using Time Difference Of Arrival Measurements From Signals Of Opportunity, Christopher M. Rondeau

Theses and Dissertations

The Global Positioning System (GPS) provides world-wide availability to high-accuracy navigation and positioning information. However, the threats to GPS are increasing, and many limitations of GPS are being encountered. Simultaneously, systems previously considered as viable backups or supplements to GPS are being shut down. This creates the need for system alternatives. Navigation using signals of opportunity (SoOP) exploits any signal that is available in a given area, regardless of whether or not the original intent of the signal was for navigation. Common techniques to compute a position estimate using SoOP include received signal strength, angle of arrival, time of arrival, …

Flow Control Application On A Submerged Inlet Characterized By Three-Component Ldv, Tina H. Reynolds

Theses and Dissertations

A submerged inlet investigation, using flow control in the form of discrete blowing, examined proximity and jet directionality to improve compressor face uniformity. The flow control locations were at the head of the ramp and part way down the ramp, providing four configurations under examination. Laser Doppler velocimetry (LDV)measurements at the throat determined the effect of the flow control based on the statistical velocity measurements. Blowing at closer proximity to the throat and targeting the largest velocity deficit region provided the best results. The airspeed and inlet velocity simulated takeoff and landing conditions; velocities ranged from Mach 0.1-0.3 at the …

Performance Characterization Of A Three-Axis Hall Effect Thruster, Spencer E. Temkin

Theses and Dissertations

No abstract provided.

Effects Of Prior Aging At 274⁰C In Argon On Inelastic Deformation Behavior Of Pmr-15 Polymer At 288⁰C: Experiment And Modeling, Joseph A. Wahlquist

Theses and Dissertations

No abstract provided.

Modeling And Preliminary Finite Element Analysis On The Spun Structure For The Cpintersep Project, Jason Carpenter, Kelly Cheng, Jeffrey Ma, Richard Pelham, Kevin Povey

Aerospace Engineering

This paper details the process of modeling and importing the model into FEA for the spun structure of the BS376 spacecraft. Engineering drawings were converted into 3D models using Pro/Engineer and then imported and into Patran for pre-processing of a Finite Element Model. To verify the Finite Element Model, several test cases were set up and solved using Nastran solver. Our simple load cases were found to be in congruence with analytical solution methods validating the finite element model.

Hot Air Balloon Navigation, Dustin Blackwell

Aerospace Engineering

This report describes a program used for navigating a hot air balloon. The program, Balloon_Trip, was written using MATLAB and gives a flight path to follow from a start position to an end position. Balloon_Trip calculates the flight path by taking in wind conditions and then flying through these different winds so as to steer the hot air balloon. The program calculates the flight path by taking into consideration at all times how the wind will propel the balloon while it is rising or falling in elevation. It then takes the most direct and least complicated, if not fastest, …

The Next Generation Cubesat: A Modular And Adaptable Cubesat Frame Design, James Dolengewicz, Lucas Whipple, Stephanie Wong

Mechanical Engineering

The goal of this project is to develop an improved next-generation CubeSat structure for Cal Poly’s PolySat program. Notable achievements include significantly increased ease of access, design to optimize payload space, improved machinability, increased modularity and a platform which allows for easy integration of future payloads.

Analysis And Comparison Of Effects Of An Airfoil Or A Rod On Supersonic Cavity Flow., William Leland Fowler

Masters Theses

The effects of an airfoil at different angles of attack and a circular cylindrical rod within the edge of the boundary layer flow at the leading edge of a cavity as a device for controlling the large pressure fluctuations (resonance tones) in the cavity were investigated. The airfoil results were compared with the rod in crossflow method positioned at the same leading edge location. The cavity used for testing corresponded to a length to depth ratio, L/D of 11.0/2.25 with a length to width ratio, L/W of 11.0/3.00 at a freestream Mach 1.84 flow. The study included measurements of dynamic …

Evaluation Of The Aerodynamics Of An Aircraft Fuselage Pod Using Analytical, Cfd, And Flight Testing Techniques, William C. Moonan

Masters Theses

The purpose of this study is to investigate the execution and validity of various predictive methods used in the design of the aerodynamic pod housing NASA’s Marshall Airborne Polarimetric Imaging Radiometer (MAPIR) on the University of Tennessee Space Institute’s Piper Navajo research aircraft. Potential flow theory and wing theory are both used to analytically predict the lift the MAPIR Pod would generate during flight; skin friction theory, empirical data, and induced drag theory are utilized to analytically predict the pod’s drag. Furthermore, a simplified computational fluid dynamics (CFD) model was also created to approximate the aerodynamic forces acting on the …

A Performance Analysis Of A Rocket Based Combined Cycle (Rbcc) Propulsion System For Single-Stage-To-Orbit Vehicle Applications, Nehemiah Joel Williams

Masters Theses

Rocket-Based Combined Cycle (RBCC) engines combine the best performance characteristics of air-breathing systems such as ramjets and scramjets with rockets with the goal of increasing payload/structure and propellant performance and thus making LEO more readily accessible. The idea of using RBCC engines for Single-Stage-To-Orbit (SSTO) trans-atmospheric acceleration is not new, but has been known for decades. Unfortunately, the availability of detailed models of RBCC engines is scarce. This thesis addresses the issue through the construction of an analytical performance model of an ejector rocket in a dual combustion propulsion system (ERIDANUS) RBCC engine. This performance model along with an atmospheric …

Automating The Data Reduction Process For More Efficient Flight Tests And Reducing The Time From Days To Hours, Joseph Kenneth Young

Masters Theses

The University of Tennessee Space Institute’s (UTSI) active airborne science program often requires extensive modification to its fleet of aircraft in order to meet mission and customer requirements. These modifications can alter the flight characteristics of the aircraft. In order to determine if the aircraft is safe to fly after modification and to find any new flight characteristics resulting from the modifications, the flight test engineer (FTE) must plan and conduct limited flight testing on the aircraft and evaluate the resulting data to ensure safety of flight. The more efficient the data reduction and analysis process the quicker the aircraft …

Development Of Cubesat Vibration Testing Capabilities For The Naval Postgraduate School And Cal Poly San Luis Obispo, Marissa Brummitt

Master's Theses

The Naval Postgraduate School is currently developing their first CubeSat, the Solar Cell Array Tester CubeSat, or NPS-SCAT. Launching a CubeSat, such as NPS-SCAT, requires environmental testing to ensure not only the success of the mission, but also the safety of other CubeSats housed in the same deployer. This thesis will address the development of CubeSat vibration testing methodology at NPS, including subsystem testing, engineering unit qualification, and flight unit testing. In addition, the new Cal Poly CubeSat Test POD Mk III will be introduced and evaluated based upon comparison with the Poly Picosatellite Orbital Deployer (P-POD). Using examples from …

Thermal Models For A 3 Cm Miniature Xenon Ion Thruster, Coleman Thomas Younger

Master's Theses

In order to support UCLA’s development of the 3 cm Miniature Xenon Ion (MiXI) thruster, Cal Poly has a 3 cm thruster under development. This version, called MiXI Cal Poly Version 1 (MiXI-CPv1), is complete and has been utilized in vacuum chamber thermal validation testing. Testing on this version was used to check the validity of heat transfer simulations modeled in SolidWorks. Investigations of the 3 cm ion thruster configuration were intended to discover the driving factors affecting the thermal behavior of the discharge chamber and surrounding design space.

Numerical simulations indicate that the heating of the samarium cobalt permanent …

Modeling Of A Gyro-Stabilized Helicopter Camera System Using Neural Networks, Nicholas Joseph Layshot

Master's Theses

On-board gimbal systems for camera stabilization in helicopters are typically based on linear models. Such models, however, are inaccurate due to system nonlinearities and complexities. As an alternative approach, artificial neural networks can provide a more accurate model of the gimbal system based on their non-linear mapping and generalization capabilities.

This thesis investigates the applications of artificial neural networks to model the inertial characteristics (on the azimuth axis) of the inner gimbal in a gyro-stabilized multi-gimbal system. The neural network is trained with time-domain data obtained from gyro rate sensors of an actual camera system. The network performance is evaluated …

Static And Fatigue Failure Response Of Woven Carbon Fiber Specimens With Double Edge Notches, Ahmad J. Amini

Master's Theses

Carbon fiber composites are continually seeing increased use in aerospace applications. It is necessary to understand their failure modes in order to properly design and perform analysis on structures constructed primarily from them. This thesis studies woven carbon fiber composites with and without double-edge notches in a series of static and fatigue tests performed on an Instron 8801 servo-hydraulic testing system.

Specimens were constructed of Advanced Composites Group product # LTM45EL woven carbon fiber pre-preg/epoxy and were cut to approximately 9-inch in length and 1-inch in width. Notches were cut into some of the specimens using a slitting saw blade …

An Investigation Of Initially Delaminated Composite Sandwich With Delamination Arrest Mechanism Under Buckling Loading, Tony D. Tran

Master's Theses

This thesis involves the development of a fiberglass-foam composite sandwich structure with the introduction of delamination arrestment keys; therefore, a study of an initially delaminated composite sandwich structure was the experimental analysis on multiple configurations in how the arrestment keys are placed.

The first part of this thesis research was to the experimental design and manufacturing of the composite sandwich plates. These plates were later cut down to the specific test dimensions and manufacturing processes for the composite sandwich plates and test specimens were created. The composite sandwich plates were manufactured using a vacuum resin infusion process. The dimensions of …

The Effectiveness Of Damage Arrestment Devices In Delaying Fastener-Hole Interaction Failures In Carbon Fiber Polyurethane Foam Composite Sandwich Panels Subjected To Static And Dynamic Loading Under Increased Temperatures, Dominic E. Surano

Master's Theses

A study was conducted to investigate simple, cost-effective manufacturing techniques to delay skin-core delamination, micro-buckling and bearing stress failures resulting from fastener-hole interactions. Composite sandwich panels, with and without damage arrestment devices (DADs), were subjected to monotonic compression at a rate of 5mm per second, and compression-compression fatigue at 50% yield at an amplitude of 65%, under temperatures of 75, 100, 125, 150, 175, and 200 °F.

The sandwiches tested were composed of two-layer cross-weave carbon fiber facesheets, a polyurethane foam core, and an epoxy film adhesive to join the two materials. The most successful method to delay the aforementioned …

Modeling And Simulation Of Autonomous Thermal Soaring With Horizon Simulation Framework, Zhenhua Li

Master's Theses

A thermal is a column of warm rising air triggered by differential heating on the ground. In recent studies UAVs were programmed to exploit this free atmospheric energy from thermals to improve their range and endurance. Researchers had successfully flown UAVs autonomously with thermal soaring method. Most research involved some form of flight simulation. Improvements to the aircraft and thermal models for simulation purpose would enable researchers to better design their UAVs and explore any potential flaws in their designs. An aircraft simulation with a thermal environment was created in Horizon Simulation Framework, a modeling and verification framework that was …

A 24ft/7.3m Parabolic Reflector Antenna Performance & Feed Design Analysis, Anthony Shelley

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science & Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Anthony Shelley on November 29, 2010.

Investigation Of Scaling Effects For A Synthetic Jet Actuator Using High And Low Fidelity Analyses, Amandine Bourlier

Master's Theses - Daytona Beach

This research presents an investigation on the scaling effects for synthetic jet actuators using Ansys-CFX and a Lumped Element Model (LEM). Synthetic jets or zero net mass-flux devices use a vibrating diaphragm to generate an oscillatory flow through a small orifice. A synthetic jet actuator can be used on MAVs as thrust generator or fixed on an airfoil for flow separation control. A Computational Fluid Dynamics (CFD) model was created, using Ansys-CFX, to be validated against referred publications. The use of mesh adaption is discussed. This baseline model was then used to complete a scaling analysis using a set of …

Neural Network Burst Pressure Prediction In Composite Overwrapped Pressure Vessels Using Mathematically Modeled Acoustic Emission Data, Junya Iizuka

Master's Theses - Daytona Beach

The purpose of this research was to predict burst pressures in composite overwrapped pressure vessels (COPV) using mathematically modeled acoustic emission (AE) data. The AE data were collected during hydrostatic burst (hydroburst) testing often 15-inch (380 mm) diameter COP Vs. The data gathered during these tests were filtered in order to remove long duration hits, multiple hit data, and obvious outliers. Based on the duration, energy, and amplitude of the AE hits, the filtered data were classified into the various failure mechanisms of composites using a MATLAB based self-organizing map (SOM) neural network. Previous research has demonstrated that the parameters …

Estimation Of Air Flow Angles Derived From An Inertial Navigation System, Brett Douglas Mather

Master's Theses - Daytona Beach

The purpose of this study is to explore the use of an Inertial Navigation System as a primary method for measuring aircraft air flow angles in flight testing. The traditional methods used to measure air flow angles consist of sensors external to the aircraft, such as an air data boom or an angle of attack probe. The advantage of using INS to measure air flow angles would be in the simplicity of the instrumentation. All components could be fixed internally, leaving minimal external modifications to the aircraft necessary for instrumentation. This would reduce costs and instrumentation time and enable air …

Orbital Tori Construction Using Trajectory Following Spectral Methods, Ralph E. Bordner Iii

Theses and Dissertations

By assuming the motion of a satellite about the earth’s geopotential mimics the known Kolmogorov-Arnold-Moser (KAM) solution of a lightly perturbed integrable Hamiltonian system, this research focused on applying trajectory following spectral methods to estimate orbital tori from sampled orbital data. From an estimated basis frequency set, orbital data was decomposed into multi-periodic Fourier series, essentially compressing ephemerides for long-term use. Real-world Global Positioning System (GPS) orbital tracks were decomposed and reconstructed with error from as low as few kilometers per coordinate axis over a 10-week span to tens of kilometers per coordinate axis over the same time period, depending …

Exploring The Effects Of International Traffic In Arms Regulations Restrictions On Innovation In The U.S. Space Industrial Base, Kalliroi L. Landry

Theses and Dissertations

The International Traffic in Arms Regulations (ITAR) are used to protect United States (U.S.) military technologies. However, changes to ITAR export controls regarding space technologies have had a major impact to the U.S. space industry. The literature mentions a concern for the health of lower-tier firms because they are a major source of innovation, but there is no additional information considering the effects of ITAR on space innovation at those lower tiers. The purpose of this thesis was to explore the implications of continuing the current ITAR restrictions with regard to innovation in the space industry. This research used a …

Satellite Capabilities Mapping - Utilizing Small Satellites, David A. Grigsby

Theses and Dissertations

The cost and schedule advantages small satellites have over larger legacy systems have been studied, but there has been very little experimentation performed to determine whether small satellites can actually deliver the capabilities of larger spacecraft. To date, a desired operational capability has not been fully realized by a scalable satellite design. Advances in sensor technology have led to significant reductions in size, weight, and power (SWaP) presenting an opportunity to exploit the evolution of space operations by using small satellites to perform specific missions. This paper describes a methodology that maps a specific set of large space vehicle capabilities …

Development Of A Small And Inexpensive Terrain Avoidance System For An Unmanned Aerial Vehicle Via Potential Function Guidance Algorithm, Shane Alan Wallace

Master's Theses

Despite the first unmanned aerial vehicle (UAV) mission being flown on Aug 22 1849 to bomb Venice UAVs have only recently began to modernize into sophisticated tools beyond simple aerial vehicles. With an increasing number of potential applications, such as cargo delivery, communications, search and rescue, law enforcement, and homeland security, the need for appropriate UAV technology advancement also arose. Here, the development of a low-cost collision avoidance system is described. Hardware was tested and selected based on predetermined constraints and goals. Additionally, a variety of potential functions were explored and assessed at their effectiveness in preventing a collision of …

Parameter Estimation Of Fundamental Technical Aircraft Information Applied To Aircraft Performance, Michael Vallone

Master's Theses

Inverse problems can be applied to aircraft in many areas. One of the disciplines within the aerospace industry with the most openly published data is in the area of aircraft performance. Many aircraft manufacturers publish performance claims, flight manuals and Standard Aircraft Characteristics (SAC) charts without any mention of the more fundamental technical information of the drag and engine data. With accurate tools, generalized aircraft models and a few curve-fitting techniques, it is possible to evaluate vehicle performance and estimate the drag, thrust and fuel consumption (TSFC) with some accuracy. This thesis is intended to research the use of aircraft …

An Investigation Of Damage Arrestment Devices Application With Fastener/Hole Interaction, Richard Vincent S. Balatbat

Master's Theses

This thesis presents a parametric study on the effects of how damage arrestment devices application interacts with a fastener in a composite sandwich panel. The primary objective of the damage arrestment device was to prevent the failure of the composite face sheet, such as crack propagation, around the hole/fastener joint. The damage arrestment devices are made of composite strips that are inserted under the face sheet to increase the overall structural strength of the panel and to prevent the propagation of failure along the hole. This was supposed to be a quicker and stronger alternative to potted inserts for composite …

Implementation Of A Conrad Probe On A Boundary Layer Measurement System, Charles Rocky Ulk

Master's Theses

This thesis presents the design, calibration, and performance evaluation of a type of two-hole pressure probe anemometer known as a Conrad probe, as well as its subsequent implementation on an autonomous, compact boundary layer measurement device and its first application for subsonic in-flight measurements of a swept wing boundary layer. Calibration of the Conrad probe was accomplished using two calibration functions and a non-nulling method for resolving in-plane flow velocity direction and magnitude over a range of ±30 degrees. This approach to calibration and application offered the advantages of rapid data acquisition with lower energy consumption than alternative methods for …