Engineering Commons^™

Development Of Load Measurement Technique For Arbitrary Shapes, Quintin J. Cockrell

Master's Theses

Obtaining aerodynamic forces and moments about all three orthogonal axes for arbitrary shapes at arbitrary orientations in a fast manner via a measurement technique specific to Cal Poly’s low-speed wind tunnel to continually obtain the forces and moments under quasi-steady conditions is explored. A Continuous Rotation Technique (CR) uses a 6-DOF load cell and stepper motor to rotate an object about an axis for a complete rotation. The forces and moments acting upon the object pass through the stepper motor and interface plates and recorded by the load cell as the object is rotated continuously a finite number of rotations. …

Structural Loads And Preliminary Structural Design For A World Speed Record-Breaking Turbo-Prop Racing Airplane, Matthew G. Slymen

Master's Theses

The Cal Poly SLO Turbo-Prop Racer project aims to design a world speed record-breaking aircraft, capable of flying more than 550 miles per hour on a 3-kilometer closed course. To further this endeavor, this thesis presents the calculations of load distributions across the aircraft’s wing and tail and preliminary structural estimates of primary structural components for verification of the loads calculations and for use in a future finite element model. The aircraft’s fundamental design characteristics effect on the structure of the aircraft, namely the unique Y-tail design, are first examined. Then, loads are calculated in accordance with the regulation dictated …

Developing A Light Curve Simulation Tool For Ground And Space-Based Observations Of Spacecraft And Debris, Andrew T. Ochoa

Master's Theses

A light curve is a plot of brightness versus time of an object. Light curves are dependent on orbit, attitude, surface area, size, and shape of the observed object. Using light curve data, several analysis methods have been developed to derive these parameters. These parameters can be used for tracking orbital debris, monitoring satellite health, and determining the mission of an unknown spacecraft.

This paper discusses the development, verification, and utilization of a tool that simulates light curve data. This tool models ground-based observations, space-based observations, self-shadowing geometry, tumbling debris, and controlled spacecraft. The main output from the tool is …

Soarnet, Deep Learning Thermal Detection For Free Flight, Jake T. Tallman

Master's Theses

Thermals are regions of rising hot air formed on the ground through the warming of the surface by the sun. Thermals are commonly used by birds and glider pilots to extend flight duration, increase cross-country distance, and conserve energy. This kind of powerless flight using natural sources of lift is called soaring. Once a thermal is encountered, the pilot flies in circles to keep within the thermal, so gaining altitude before flying off to the next thermal and towards the destination. A single thermal can net a pilot thousands of feet of elevation gain, however estimating thermal locations is not …

Comparing Radiation Shielding Potential Of Liquid Propellants To Water For Application In Space, John Czaplewski

Master's Theses

The radiation environment in space is a threat that engineers and astronauts need to mitigate as exploration into the solar system expands. Passive shielding involves placing as much material between critical components and the radiation environment as possible. However, with mass and size budgets, it is important to select efficient materials to provide shielding. Currently, NASA and other space agencies plan on using water as a shield against radiation since it is already necessary for human missions. Water has been tested thoroughly and has been proven to be effective. Liquid propellants are needed for every mission and also share similar …

Development Of A Hybrid Particle Continuum Solver, Anthony J. Gay

Master's Theses

When simulating complex flows, there are some physical situations that exhibit large fluctuations in particle density such as: planetary reentry, ablation due to arcing, rocket exhaust plumes, etc. When simulating these events, a high level of physical accuracy can be achieved with kinetic methods otherwise known as particle methods. However, this high level of physical accuracy requires large amounts of computation time. If the simulated flow is in collisional equilibrium, then less computationally intensive continuum methods, otherwise known as fluid methods, can be utilized. Hybrid Particle-Continuum (HPC) codes attempt to blend particle and fluid solutions in order to reduce computation …

Design And Validation Of An Led-Based Solar Simulator For Solar Cell And Thermal Testing, Matthew Gunther

Master's Theses

An LED-based solar simulator has been designed, constructed, and qualified under ASTM standards for use in the Cal Poly Space Environments Laboratory. The availability of this simulator will enhance the capability of undergraduate students to evaluate solar cell and thermal coating performance, and offers further research opportunities. The requirements of ASTM E927-19 for solar simulators intended for photovoltaic cell testing were used primarily, supplemented by information from ASTM E491-73 for solar simulators intended for spacecraft thermal vacuum testing. Three main criteria were identified as design goals - spectral match ratio, spatial non-uniformity, and temporal instability. An electrical design for an …

Secondary Uses Of Ballutes After Aerocapture, Josiah Shelton

Master's Theses

Aerocapture is a method for spacecraft orbital insertion that is currently being assessed for use in interplanetary missions. This method would use a low periapsis hyperbolic entry orbit to induce drag allowing the spacecraft to slow down without the use of a propulsion system. This is accomplished by using a ballute (balloon parachute), which is released after the appropriate change in velocity necessary to achieve the desired planetary orbit. Once released, the ballute could deploy a secondary mission vehicle. A MATLAB simulation was run to understand the environment a secondary payload would undergo, such as heating and deceleration, as well …

Thermal Modeling And Testing Of The Blue Thermal Vacuum Chamber, Madeline R. Jensma

Master's Theses

The Blue Thermal Vacuum Chamber (TVAC) located in the Space Environments Laboratory at California Polytechnic State University, San Luis Obispo (Cal Poly), may be used for thermal vacuum testing of test articles that fit with in the semi cylindrical test section that has a radius of approximately 18 cm and a length of 61 cm. The potential test articles include CubeSat systems and subsystem. The Blue TVAC can also be used for educational and research purposes. The goal of this thesis project is to develop a thermal model of the Blue TVAC to predict and analyze the thermal response of …

A System Architecture For Phased Development Of Remote Suas Operation, Eric Ashley

Master's Theses

Current airspace regulations require the remote pilot-in-command of an unmanned aircraft systems (UAS) to maintain visual line of sight with the vehicle for situational awareness. The future of UAS will not have these constraints as technology improves and regulations are changed. An operational model for the future of UAS is proposed where a remote operator will monitor remote vehicles with the capability to intervene if needed. One challenge facing this future operational concept is the ability for a flight data system to effectively communicate flight status to the remote operator. A system architecture has been developed to facilitate the implementation …

Performance Enhancement And Characterization Of An Electromagnetic Railgun, Paul M. Gilles

Master's Theses

Collision with orbital debris poses a serious threat to spacecraft and astronauts. Hypervelocity impacts resulting from collisions mean that objects with a mass less than 1g can cause mission-ending damage to spacecraft. A means of shielding spacecraft against collisions is necessary. A means of testing candidate shielding methods for their efficacy in mitigating hypervelocity impacts is therefore also necessary. Cal Poly’s Electromagnetic Railgun was designed with the goal of creating a laboratory system capable of simulating hypervelocity (≥ 3 km/s) impacts. Due to several factors, the system was not previously capable of high-velocity (≥ 1 km/s) tests. A deficient projectile …

Development Of A Tailored Flight Test Approach For Small Unmanned Aircraft Systems, Neil A. Wolfe

Master's Theses

This document contains the details of a study conducted to determine an effective performance flight test approach specifically for small Unmanned Aircraft Systems (sUAS). This was done by taking proven procedures and documentation from the FAA and the Air Force for manned aircraft and tailoring them specifically for use with sUAS flight test programs. A ‘sUAS Flight Testing Handbook’ was created from the proceedings to aid commercial organizations and recreational developers conducting sUAS research without access to flight test experience. A performance flight test program was conducted with the AeroVironment RQ-20 Puma sUAS using the developed approach to verify that …

Nanosatellite Launch Data-Logger (Sync), Christopher Martin Gerdom

Master's Theses

CubeSat designers are increasingly looking to incorporate delicate structures and optics into their payloads. These delicate payloads, however, may not survive the required absolute-worst-case launch vibration testing needed for flight certification. To help address this problem, and to better match testing conditions to real-world launch environments, this thesis introduces Sync, a compact 1/4U CubeSat payload designed to collect data on the vibrations and thermal environments CubeSats experience inside a deployer on the way to orbit. This data can be used to better understand the launch environment for different vehicles, and help develop new, more realistic testing guidelines that could enable …

An Evaluation Of Ultrasonic Shot Peening And Abrasive Flow Machining As Surface Finishing Processes For Selective Laser Melted 316l, Rhys Gilmore

Master's Theses

Additive Manufacturing, and specifically powder bed fusion processes, have advanced rapidly in recent years. Selective Laser Melting in particular has been adopted in a variety of industries from biomedical to aerospace because of its capability to produce complex components with numerous alloys, including stainless steels, nickel superalloys, and titanium alloys. Post-processing is required to treat or solve metallurgical issues such as porosity, residual stresses, and surface roughness. Because of the geometric complexity of SLM produced parts, the reduction of surface roughness with conventional processing has proven especially challenging. In this Thesis, two processes, abrasive flow machining and ultrasonic shot peening, …

Determining Feasibility Of A Propulsionless Microsatellite Formation Flight Mission, Aaron Levis

Master's Theses

Benefits of developing missions with multiple formation flying spacecraft as an alternative to a traditional monolithic vehicle are becoming apparent. In some cases, these missions can lower cost and increase flexibility among other situational advantages. However, there are various limitations that are imposed by these missions that are centered on the concept of maintaining the necessary formation. One such limitation is that of the propulsion system required for each spacecraft. To mitigate the complexity and mass of the onboard propulsion, the pairing of electromagnetic actuators and differential drag to replace the functionality of a propulsive system is investigated. By using …

The Design And Implementation Of A Supersonic Indraft Tube Wind Tunnel For The Demonstration Of Supersonic Flows, Daniel Kenneth Johnson

Master's Theses

Historically, the endeavor of scale testing flight vehicles at supersonic Mach numbers, especially for long durations, has required the development of closed-loop wind tunnels, which are extremely expensive both to build and operate due to the high complexity and incredible power required to drive such a system. The intermittent blowdown wind tunnel, indraft tunnel, and shock tunnel have alleviated many of these cost requirements to some degree, whilst facilitating testing at very high Mach numbers and enthalpies; however, these systems require the handling of gases at pressures and temperatures that can be prohibitive for many university settings. The Ludwieg tube …

Sysml Output Interface And System-Level Requirement Analyzer For The Horizon Simulation Framework, Viren Kishor Patel

Master's Theses

Model-Based Systems Engineering in industry has been constantly increasing its presence within the aerospace industry. SysML is one such MBSE tool that shows complex system organization and relationships. The Horizon Simulation Framework is another MBSE tool, created by Cal Poly students, that gives users the ability to run “day-in-the-life” simulations of systems. Finding a way to link these two tools could allow systems engineers to reap the benefits of both.

This thesis investigates the background and design process involved with developing the code that can convert an output file generated in SysML, into a format specifically made for the Horizon …

Manufacturing And Instrumentation Of An Open End Compressed Air Shock Tube, Josue O. Ruiz

Master's Theses

Shock tubes have been used extensively to study shock wave structures and high speed flow features. The purpose of constructing this open end shock tube was to have the ability to produce shock waves in a laboratory setting but also understand the exit flow coming out which can be applied to future studies that are beyond the scope of this work. This undertaking would require that an open end shock tube be built and instrumented with PCB Integrated Circuit Piezoelectric (ICP) Pressure Sensor Model 113B24 that would then be connected to a PCB Model 482C05 Signal Conditioner with the purpose …

Atomic Oxygen Considerations For Leo De-Orbit Trajectories Using Solar Sails, Daniel A. Fugett

Master's Theses

Solar sails have the potential to benefit many future space exploration missions, but they lack the heritage required for present-day use. To grow confidence in solar sail technology, they could be deployed on LEO satellites higher than 600 km to help de-orbit the satellite within 25 years upon mission termination. To determine how atomic oxygen would affect the solar sail, material from Lightsail-2 was tested in a thermal-energy, isotropic, atomic oxygen vacuum chamber based in the space environments laboratory in California Polytechnic State University. The sail material, aluminized Mylar, was tested for its survivability on both the coated and uncoated …

Wing Deflection Analysis Of 3d Printed Wind Tunnel Models, Matthew G. Paul

Master's Theses

This work investigates the feasibility of producing small scale, low aerodynamic loading wind tunnel models, using FDM 3D printing methods, that are both structurally and aerodynamically representative in the wind tunnel. To verify the applicability of this approach, a 2.07% scale model of the NASA CRM was produced, whose wings were manufacturing using a Finite Deposition Modeling 3D printer. Experimental data was compared to numerical simulations to determine percent difference in wake distribution and wingtip deflection for multiple configurations.

Numerical simulation data taken in the form of CFD and FEA was used to validate data taken in the wind tunnel …

Mass Estimation Through Fusion Of Astrometric And Photometric Data Collection With Application To High Area-To-Mass Ratio Objects, Matthew Richardson

Master's Theses

This thesis work presents the formulation for a tool developed in MATLAB to determine the mass of a space object from the fusion of astrometric and photometric data. The application for such a tool is to better model the mass estimation method used for high area-to-mass ratio objects found in high altitude orbit regimes. Typically, the effect of solar radiation pressure is examined with angles observations to deduce area-to-mass ratio calculations for space objects since the area-to-mass ratio can greatly affect its orbital dynamics. On the other hand, photometric data is not sensitive to mass but is a function of …

The Effect Of Biocomposite Material In A Composite Structure Under Compression Loading, Benjamin Andrew Sweeney

Master's Theses

While composite structures exhibit exceptional strength and weight saving possibilities for engineering applications, sometimes their overall cost and/or material performance can limit their usage when compared to conventional structural materials. Meanwhile ‘biocomposites’, composite structures consisting of natural fibers (i.e. bamboo fibers), display higher cost efficiency and unique structural benefits such as ‘sustainability’. This analysis will determine if the integration of these two different types of composites are beneficial to the overall structure. Specifically, the structure will consist of a one internal bamboo veneer biocomposite ply; and two external carbon fiber weave composite plies surrounding the bamboo biocomposite. To acquire results …

Assessment Of Asymmetric Flight On Solar Uas, Eric Belfield

Master's Theses

An investigation was conducted into the feasibility of using an unconventional flight technique, asymmetric flight, to improve overall efficiency of solar aircraft. In this study, asymmetric flight is defined as steady level flight in a non-wings-level state in- tended to improve solar incidence angle. By manipulating aircraft orientation through roll angle, solar energy collection is improved but aerodynamic efficiency is worsened due to the introduction of additional trim drag. A point performance model was devel- oped to investigate the trade-off between improvement in solar energy collection and additional drag associated with asymmetric flight. A mission model with a focus on …

Development Of Cal Poly's Shock Table, Christopher D. Risner

Master's Theses

Shock is one of the environmental tests that a spacecraft must pass before being cleared for launch. Shock testing poses a challenging data acquisition issue and careful selection of equipment is crucial to creating a successful shock test facility. Cal Poly’s CubeSat programs can currently perform all environmental testing other than shock themselves, so a quality shock table would be useful. Previous groups of students had developed a shock table, and this paper details the improvement and characterization of that shock table’s behavior. Several adjustable parameters were tested and documented to discover trends in the shock table’s response to an …

Evaluation Of Efficiency Of Various Materials To Shield From Radiation In Space Using The Monte Carlo Transport Code Called Fluka, Roman Savinov

Master's Theses

The purpose of this study is to improve spacecraft shielding from radiation in space. It focuses on the evaluation of shielding efficiency of different materials. The efficiency of a shield is evaluated by the dose profile within the shield and the amount of dose absorbed by a target using the Monte Carlo transport code called FLUKA. The output of this code is validated by recreating the experiments from published papers and comparing the results. Once the FLUKA’s output is validated, the efficiency of sixteen materials, subject to SPE and GCR sources, are evaluated. The efficiency comparison is made by fixing …

Axisymmetric Bi-Propellant Air Augmented Rocket Testing With Annular Cavity Mixing Enhancement, Allen A. C. Capatina

Master's Theses

Performance characterization was undertaken for an air augmented rocket mixing duct with annular cavity configurations intended to produce thrust augmentation. Three mixing duct geometries and a fully annular cavity at the exit of the nozzle were tested to enable thrust comparisons. The rocket engine used liquid ethanol and gaseous oxygen, and was instrumented with sensors to output total thrust, mixing duct thrust, combustion chamber pressure, and propellant differential pressures across Venturi flow measurement tubes.

The rocket engine was tested to thrust maximum, with three different mixing ducts, three major combustion pressure sets, and a nozzle exit plane annular cavity (a …

Development Of Tools Needed For Radiation Analysis Of A Cubesat Deployer Using Oltaris, Marycarmen Gonzalez-Dorbecker

Master's Theses

Currently, the CubeSat spacecraft is predominantly used for missions at Low- Earth Orbit (LEO). There are various limitations to expanding past that range, one of the major ones being the lack of sufficient radiation shielding on the Poly-Picosatellite Orbital Deployer (P-POD). The P-POD attaches to a launch vehicle transporting a primary spacecraft and takes the CubeSats out into their orbit. As the demand for interplanetary exploration grows, there is an equal increase in interest in sending CubeSats further out past their current regime. In a collaboration with NASA’s Jet Propulsion Laboratory (JPL), students from the Cal Poly CubeSat program worked …

Development Of An Interactive Wave Drag Capability For The Openvsp Parametric Geometry Tool, Michael Jon Waddington

Master's Theses

Minimizing wave drag is critical to successful and efficient transonic and supersonic flight. Area-ruling is the process of managing the cross-sectional area of an aircraft to lessen the wave drag experienced in flight. Effectively calculating the necessary areas for a given aircraft can be difficult, and existing tools for conducting a wave drag analysis often carry limitations in both functionality and availability.

In this work, the author utilized an existing parametric geometry tool named OpenVSP to create an interactive design tool for approximating zero-lift wave drag. Here, the wave drag calculation methodology used in industry for decades is combined with …

A Study On The Vibrational Performance Characteristics Of An E22 Isolator After Outgassing And Bake-Out, Alma Melendez

Master's Theses

The launch environment experiences many vibration, shock, and acoustic loads. A great concern is the high random vibration levels that can damage components and spacecraft structures, which can cause a mission failure. An effective method of reducing high frequency energy is using isolators. Overall, the need for vibration isolation has been increasing because there has been an increase in the use of mechanisms in which vibrations are prevalent. In addition, there has not been extensive research on the effects of isolators that are outgassed and cured. Therefore, it is important to investigate and understand the vibrational effects on isolators. It …

A Study Of The Collisional Evolution Of Orbital Debris In Geopotential Wells And Geo Disposal Orbits, Christina R. Diaz

Master's Theses

This thesis will present the effects of the orbital debris evolution in two key areas: the geosynchronous disposal orbit regime known as “graveyard” and the two geopotential wells found in 105◦ W and 75◦ E longitude bins. After developing a GEO specific orbit propagator for NASA Johnson Space Center’s Orbital Debris Of- fice, collisions were simulated throughout these regimes using a low velocity breakup model. This model considered the effects of perturbations particularly non-spherical Earth effects (specifically sectorial and zonal harmonics), lunar effects, third body effects and solar radiation pressure effects. The results show that CDPROP does well in simulating …