Engineering Commons^™

Field Testing The Effects Of Low Reynolds Number On The Power Performance Of The Cal Poly Wind Power Research Center Small Wind Turbine, John B. Cunningham

Master's Theses

This thesis report investigates the effects of low Reynolds number on the power performance of a 3.74 m diameter horizontal axis wind turbine. The small wind turbine was field tested at the Cal Poly Wind Power Research Center to acquire its coefficient of performance, C­_p, vs. tip speed ratio, λ, characteristics. A description of both the wind turbine and test setup are provided. Data filtration and processing techniques were developed to ensure a valid method to analyze and characterize wind power measurements taken in a highly variable environment. The test results demonstrated a significant drop in the …

Hypersonic Heat Transfer Load Analysis In Star-Ccm+, Robert Comstock

Master's Theses

This thesis investigates the capabilities of STAR-CCM+, a Computational Fluid Dynamics (CFD) software owned by Siemens, in predicting hypersonic heat transfer loads on forward-facing surfaces. Results show that STAR-CCM+ predicted peak heat transfer loads within +/- 20% of experimental data on the leading edge of a delta wing design from the X-20 Dyna-Soar program with 73^o of sweep. Steady-state laminar simulations were run as replications of wind tunnel tests documented in NASA CR-535, a NASA technical report that measured and studied the hypersonic pressure and heat transfer loads on preliminary X- 20 wing designs across a wide range of …

Spacecraft Trajectory Optimization Suite (Stops): Design And Optimization Of Multiple Gravity-Assist Low-Thrust (Mgalt) Trajectories Using Modern Optimization Techniques, Michael G. Malloy

Master's Theses

The information presented in the thesis is a continuation of the Spacecraft Trajectory Optimization Suite (STOpS). This suite was originally designed and developed by Timothy Fitzgerald and further developed by Shane Sheehan, both graduate students at California Polytechnic State University, San Luis Obispo. Spacecraft utilizing low-thrust transfers are becoming more and more common due to their efficiency on interplanetary trajectories, and as such, finding the most optimal trajectory between two planets is something of interest. The version of STOpS presented in this thesis uses Multiple Gravity-Assist Low-Thrust (MGALT) trajectories paired with the island model paradigm to accomplish this goal. The …

B-Plane Targeting With The Spacecraft Trajectory Optimization Suite, Jared Graef

Master's Theses

In interplanetary trajectory applications, it is common to design arrival trajectories based on B-plane target values. This targeting scheme, B-plane targeting, allows for specific target orbits to be obtained during mission design. A primary objective of this work was to implement B-plane targeting into the Spacecraft Trajectory Optimization Suite (STOpS). This work was based on the previous versions of STOpS done by Fitzgerald and Sheehan, however STOpS was redeveloped from MATLAB to python. This updated version of STOpS implements 3-dimensional computation, departure and arrival orbital phase modeling with patched conics, B-plane targeting, and a trajectory correction maneuver. The optimization process …

Investigation On The Use Of Small Aperture Telescopes For Leo Satellite Orbit Determination, Luis R. Curiel Iii

Master's Theses

The following thesis regards the use of small aperture telescopes for space domain awareness efforts. The rapidly populating space domain was motivation for the development of a new operation scheme to conduct space domain awareness feasibility studies using small telescopes. Two 14-inch Schmidt-Cassegrain Telescopes at the California Polytechnic State University and the Air Force Research Lab in Kirtland AFB, NM, in conjunction with a dedicated CCD camera and a commercial DSLR camera, were utilized to conduct optical observations on satellites in Earth orbit.

Satellites were imaged during August 2019, and from January 2020 to March 2020, resulting in the collection …

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 …

Interplanetary Trajectory Optimization With Automated Fly-By Sequences, Emily Ann Doughty

Master's Theses

Critical aspects of spacecraft missions, such as component organization, control algorithms, and trajectories, can be optimized using a variety of algorithms or solvers. Each solver has intrinsic strengths and weaknesses when applied to a given optimization problem. One way to mitigate limitations is to combine different solvers in an island model that allows these algorithms to share solutions. The program Spacecraft Trajectory Optimization Suite (STOpS) is an island model suite of heterogeneous and homogeneous Evolutionary Algorithms (EA) that analyze interplanetary trajectories for multiple gravity assist (MGA) missions. One limitation of STOpS and other spacecraft trajectory optimization programs (GMAT and Pygmo/Pagmo) …

Numerical Analysis Of A Circulation Control Wing, Luke W. Bodkin

Master's Theses

The objective of this thesis was to develop an experimental method to research circulation control wings using numerical analysis. Specifically, it is of interest to perform 3D wind tunnel testing on a circulation control wing in the Cal Poly Low Speed Wind Tunnel (CPLSWT). A circulation control wing was designed and analyzed to determine the feasibility of this testing.

This study relied on computational fluid dynamics (CFD) simulations as a method to predict the flow conditions that would be seen in a wind tunnel test. A CFD simulation was created of a wing model in a wind tunnel domain. Due …

Low-Cost Reaction Wheel Design For Cubesat Applications, Nicholas J. Bonafede Jr.

Master's Theses

As science instruments on CubeSats become more sensitive to the attitude of the spacecraft, better methods must be employed to provide the accuracy needed to complete the planned mission. While systems that provide the accuracy required are available commercially, these solutions are not cost-effective, do not allow the design to be tailored to a specific mission, and most importantly, do not give students hand-on experience with attitude control actuators. This thesis documents the design, modeling, and simulation of a low-cost, student-fabricated, reaction wheel system for use in 3U CubeSat satellites. The entire design process for the development of this reaction …

Pathfinding Interplanetary Bus Capability For The Cal Poly Cubesat Laboratory Through The Development Of A Phobos-Deimos Mission Concept, Alyssa M. Ralph

Master's Theses

With the rise of CubeSats and the demonstration of their many space applications, there is interest in interplanetary CubeSats to act for example as scientific investigations or communications relays. In line with the increasing demand for this class of small satellites, the Cal Poly CubeSat Lab (CPCL) seeks to develop a bus that could support an interplanetary science payload. To facilitate this, a mission concept to conduct science of the moons of Mars, Phobos and Deimos, is investigated by determining the mission needs for a CubeSat in a Phobos-Deimos cycler orbit through the development of a baseline design to meet …

Limitations Of Initial Orbit Determination Methods For Low Earth Orbit Cubesats With Short Arc Orbital Passes, James P. Johnson

Master's Theses

This thesis will focus on the performance of angles only initial orbit determi- nation (IOD) methods on observational data of low Earth orbit (LEO) CubeSats. Using data obtained by Lockheed Martin’s Space Object Tracking (SpOT) facil- ity, four methods: Gauss, Double-R, Gooding and Assumed Circular, will use different amounts of orbital arc to determine which methods perform the best in the short arc regime of less than 10 degrees of orbital arc. Once the best method for estimating the orbit is determined, there will be analysis on whether these IOD methods are accurate enough to predict a secondary observation session. …

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 …

Initial Orbit Determination Error Analysis Of Low-Earth Orbit Rocket Body Debris And Feasibility Study For Debris Cataloguing From One Optical Facility, Kyle Stoker

Master's Theses

This paper is predicated on determining the effectiveness of angles-only initial orbit determination (IOD) methods when limited observational data is available for low-Earth orbit (LEO) rocket body debris. The analysis will be conducted with data obtained from Lockheed Martin Space’s Space Object Tracking (SpOT) facility, focusing on their observational data from 2018 that contains tracking of rocket body debris for less than one minute per overhead pass. After the IOD accuracies are better understood, a feasibility study will follow that investigates the possibility of cataloguing LEO orbital debris from a single optical observation facility with similar observational capabilities as that …

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 …

Pocket Rocket: A 1u+ Propulsion System Design To Enhance Cubesat Capabilities, James M. Harper

Master's Theses

The research presented provides an overview of a 1U+ form factor propulsion system design developed for the Cal Poly CubeSat Laboratory (CPCL). This design utilizes a Radiofrequency Electrothermal Thruster (RFET) called Pocket Rocket that can generate 9.30 m/s of delta-V with argon, and 20.2 ± 3 m/s of delta-V with xenon. Due to the demand for advanced mission capabilities in the CubeSat form factor, a need for micro-propulsion systems that can generate between 1 – 1500 m/s of delta-V are necessary.

By 2019, Pocket Rocket had been developed to a Technology Readiness Level (TRL) of 5 and ground tested in …

A Study Of The Utilization Of Panel Method For Low Aspect Ratio Wing Analysis, William Barton D. Newey

Master's Theses

This study demonstrates the applicability of using a modified application strategy of panel method to analyze low aspect ratio wings at preliminary design phases. Conventional panel methods fail to capture the leading edge vortex (LEV) that is shed by wings with low aspect ratios, typically below 2 depending on planform. This aerodynamic phenomenon contributes to a significant amount of the lift of these wings and the result is a drastic underestimation of the lift characteristics when analyzed by conventional panel method. To capture the effect of the leading edge vortex, a panel method code was used with an extended definition …

Design Of A Martian Communication Constellation Of Cubesats, Scott J. Pirkle

Master's Theses

Spacecraft operating on the Martian surface have used relay satellites as a means of improving communication capabilities, mainly in terms of bandwidth and availability. However, the spacecraft used to achieve this have been large spacecraft (1000s of kilograms) and were not designed with relay capability as the design priority. This thesis explores the possibility of using a CubeSat-based constellation as a communications network for spacecraft operating on the Martian surface. Brute-force techniques are employed to explore the design space of possible constellations. An analysis of constellation configurations that provide complete, continuous coverage of the Martian surface is presented. The stability …

Three Axis Attitude Control System Design And Analysis Tool Development For The Cal Poly Cubesat Laboratory, Liam T. Bruno

Master's Theses

The Cal Poly CubeSat Laboratory (CPCL) is currently facing unprecedented engineering challenges—both technically and programmatically—due to the increasing cost and complexity of CubeSat flight missions. In responding to recent RFPs, the CPCL has been forced to find commercially available solutions to entire mission critical spacecraft subsystems such as propulsion and attitude determination & control, because currently no in-house options exist for consideration. The commercially available solutions for these subsystems are often extremely expensive and sometimes provide excessively good performance with respect to mission requirements. Furthermore, use of entire commercial subsystems detracts from the hands-on learning objectives of the CPCL by …

A Parametric Study Of Formation Flight Of A Wing Based On Prandtl's Bell-Shaped Lift Distribution, Kyle S. Lukacovic

Master's Theses

The bell-shaped lift distribution (BSLD) wing design methodology advanced by Ludwig Prandtl in 1932 was proposed as providing the minimum induced drag. This study used this method as the basis to analyze its characteristics in two wing formation flight. Of specific interest are the potential efficiency savings and the optimal positioning for formation flight. Additional comparison is made between BSLD wings and bird flight in formation.

This study utilized Computational Flow Dynamics (CFD) simulations on a geometric modeling of a BSLD wing, the Prandtl-D glider. The results were validated by modified equations published by Prandtl, by CFD modeling published by …

Conceptual Design Of A South Pole Carrier Pigeon Uav, Kendrick M. Dlima

Master's Theses

Currently, the South Pole has a large data problem. It is estimated that 1.2 TB of data is being produced every day, but less than 500 GB of that data is being uploaded via aging satellites to researchers in other parts of the world. This requires those at the South Pole to analyze the data and carefully select the parts to send, possibly missing out on vital scientific information. The South Pole Carrier Pigeon will look to bridge this data gap.

The Carrier Pigeon will be a small unmanned aerial vehicle that will carry a 30 TB solid-state hard drive …

Design, Validation, And Verification Of The Cal Poly Educational Cubesat Kit Structure, Nicholas B. Snyder

Master's Theses

In this thesis, the development of a structure for use in an educational CubeSat kit is explored. The potential uses of this kit include augmenting existing curricula with aspects of hands on learning, developing new ways of training students on proper space systems engineering practices, and overall contributing to academic capacity building at Cal Poly and its collaborators. The design improves on existing CubeSat kit structures by increasing accessibility to internal components by implementing a modular backplane system, as well as adding the ability to be environmentally tested. Manufacturing of the structure is completed with both additive (Fused Deposition Modeling …

A Study Of The Design Of Adaptive Camber Winglets, Justin J. Rosescu

Master's Theses

A numerical study was conducted to determine the effect of changing the camber of a winglet on the efficiency of a wing in two distinct flight conditions. Camber was altered via a simple plain flap deflection in the winglet, which produced a constant camber change over the winglet span. Hinge points were located at 20%, 50% and 80% of the chord and the trailing edge was deflected between -5° and +5°. Analysis was performed using a combination of three-dimensional vortex lattice method and two-dimensional panel method to obtain aerodynamic forces for the entire wing, based on different winglet camber configurations. …

A Study Of The Standard Cirrus Wing Lift Distribution Versus Bell Shaped Lift Distribution, William H. Bergman

Master's Theses

This thesis discusses a comparison of the differences in aerodynamic performance of wings designed with elliptical and bell-shaped lift distributions. The method uses a Standard Cirrus sailplane wing with a lift distribution associated with the induced drag benefits of an elliptical distribution (span efficiency = 0.96) as the basis of comparison. The Standard Cirrus is a standard class sailplane with 15-meter wingspan that was designed by Schempp-Hirth in 1969. This sailplane wing was modeled and analyzed in XFLR5, then validated against existing wind tunnel airfoil data, and Standard Cirrus flight test data. The root bending moment of the baseline wing …

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 …