Engineering Commons^™

A Feasibility Study On Series Hybrid-Electric Propulsion For Narrow-Body Transport Aircraft, Carver J. Glomb

Master's Theses

As global climate change accelerates, the reduction of carbon emissions has become a critical objective across multiple industries. The aviation sector, however, has lagged behind other transportation domains in implementing sustainable alternatives, despite growing demand for air travel. Recent research and emerging technologies have proposed several decarbonization pathways, including hydrogen fuel, sustainable aviation fuels (SAFs), and hybrid or fully electric propulsion systems. Among these, series hybrid-electric propulsion has received comparatively limited attention, particularly for application in transport-class aircraft. This study investigates the feasibility and emissions-reduction potential of a series hybrid-electric propulsion architecture applied to a representative narrow-body platform. A Python-based …

Sentry V3: Extending Context Switches On A Trusted Secure Coprocessor, Mark Kong

Master's Theses

Software correctness and integrity is only ensured through trust in the un- derlying hardware. However, modern computer systems are complex to design and secure. Thus, given the choice between performance and security, companies will often prioritize performance, resulting in vulnerable systems. This creates exploitable systems that must be patched retroactively because business value performance over security. One approach to this issue is to separate the root of security from the rest of the system to create a minimal trusted computing base. Trustguard is one instance of this. Trustguard implements a Containment Architecture with Ver- ified Output (CAVO) model which shows …

Optimizing Web Servers With Io_Uring, Mihika Nigam

Master's Theses

Modern web servers face unprecedented demands for high throughput and low latency [10] [11]. Yet, even the state-of-the-art optimizations often fail under heavy workloads on existing infrastructure. Despite advancements in hardware, communication between applications and the kernel remains a critical bottleneck.

Industry surveys reveal that over 50% of production servers still rely on traditional epoll-based architectures [5]. This research aims to investigate and characterize Linux’s new io_uring subsystem, which has the potential to overcome these challenges. Through controlled load testing of various existing architectures like event-driven, multi-process, and multi-threaded architectures (including other commercial servers), we demonstrate how io_uring can help …

Enhancement Of A Python Integral Boundary Layer Method, Jeffrey T. Azuma

Master's Theses

This thesis presents a series of additions to a Python based integral boundary layer software library known as PyBL. This library provides the user the means to calculate boundary layer properties using different models for boundary layer behavior. The additions feature the integration of a set of new laminar and turbulent integral boundary layer models originally developed for and currently found in the program XFOIL. These models were modified to fit the ODE solver method at the foundation of PyBL. A new method for PyBL that stitches a laminar and turbulent solution together has been developed to improve the ability …

Development And Testing Of A Lab-Scale Resonance Igniter For Rocket Propulsion Applications, Aidan Caplan

Master's Theses

The resonance igniter is a type of rocket engine ignition system that initiates spontaneous combustion without using an external ignition source. This is possible because the activation energy needed for the combustion reaction to take place is provided by the igniter as it receives propellant flow. This can simplify the igniter hardware and lends it high re-usability while enabling the use of high-efficiency propellant combinations. Its potential benefits could make it a desirable alternative to traditional approaches such as using spark igniters or hypergolic propellants. The present research strove to inaugurate the study of the resonance igniter at Cal Poly …

Using Hydrologic And Hydraulic Simulations To Predict Near-Term Effects Of Beaver Habitat Restoration On Flood Flows, Luke S. Stewart

Master's Theses

There is a growing need to predict the complex hydrologic and hydraulic effects of beaver-maintained wetlands. This study uses relatively simple inputs and a replicable methodology to predict flood flow impacts of beaver habitat restoration at the site design scale using the engineering industry’s customary hydrology and hydraulic modeling approach. This study focuses on Toro Creek, the primary drainage for a 15.2 square mile watershed on the California Central Coast.

A hydrologic model of Toro Creek watershed was developed in HEC-HMS to approximate saturated soil conditions typical of late-spring flooding events observed in the region. The hydrologic model was calibrated …

Data-Driven Product Recommendations: A Decision Support Framework Utilizing Customer Reviews, Tyler A. Lopez

Master's Theses

With the considerable presence of e-commerce in society, vast number of purchasable goods, and increasing brand variety, consumers are faced with the challenge of buying products that they perceive to be of greatest value to them. To assist consumers with making better informed decisions, e-commerce websites allow individuals to post their own experiences and score the products that they purchase. Despite this information, the variety of experiences and feedback that consumers share do not always lead to clarity on whether a product is best suited for the purchaser. To help guide customers through a simplified purchasing process from the perspective …

Design And Development Of A Laboratory Star Tracker System, Kevin D. Iverson

Master's Theses

This thesis presents the design, calibration, and validation of a low-cost star tracker system and hardware-in-the-loop testbed intended for small satellite applications. The system is composed entirely of commercial off-the-shelf components and integrates both a custom star tracker and a screen-based star field simulator for controlled, repeatable testing. An analytical modeling approach was used in the early design phase to predict system accuracy based on key optical and geometric parameters, informing the selection and configuration of components and guiding the development of calibration routines.

A simulation environment was developed to validate the star tracker software and assess the impact of …

Hardware-In-The-Loop Testing For The Polysim Adcs Lab, Shealyn P. Miller

Master's Theses

Hardware-in-the-loop, HIL, testing is an important tool for the validation and verification of systems in the aerospace industry. A common subsystem to be tested using HIL testing is the attitude, dynamics, and controls subsystem, ADCS. This is due to HIL tests using realistic simulations of the space environment to control physical hardware. To create a HIL test, a simulation and HIL interface are needed to test and communicate with hardware. Using a Speedgoat Performance Real-Time Target Machine to communicate with a Raspberry Pi and a Simulink model, three tests were conducted to ensure communication was functioning properly. A simulation, in …

Effect Of Manufacturing And Machining Process On Recycled Composite Connecting Rods Under Tension And Compression, Walter W. Oppelt

Master's Theses

Carbon fiber reinforced polymer (CFRP) is an engineering material renowned for its high-strength and low-density material properties. Such properties make CFRPs especially useful for applications across many industries, including aerospace, automotive, marine, sporting goods, oil and gas, and more. However, with such favorable material properties comes the cost of high energy usage required to produce raw carbon fiber. Recycled carbon fiber (rCF) has emerged as a promising alternative, offering a significant reduction in energy usage. This research explores the viability of applying recycled CFRPs to internal combustion engines to both reduce energy costs during manufacturing and while in use. Mechanical …

Myceli-Yum: Elucidating Structure-Property Relationships For Polymer Degradation By Mycelial Digestion, Jordan Scott Ford

Master's Theses

Since the industrial entrance of polymer plastic materials, plastic has become ubiquitous in both everyday use and waste. Due to inefficiencies and knowledge gaps, current recycling methods are not able to account for the high scale of plastic waste, resulting in the bulk of this waste being landfilled, mishandled, and deposited in the environment. Mycelium, the microorganism responsible for fruiting mushroom bodies and mold growth, holds potential to reduce plastic waste and can potentially be utilized as a method of industrial recycling. Following a drug-design approach, the active site of mycelial enzymes responsible for natural biopolymer degradation have been assessed …

Ev Microgrid Inspired Open-Source Power Inverter, Bryan A. Carrillo Martinez

Master's Theses

The development of open-source power electronics platforms plays an instrumental role in accelerating microgrid deployment, electric vehicle (EV) integration, and educational access to embedded power electronic converters. This thesis presents the design, implementation, and validation of the Atinverter V2, an open-source DC to AC inverter intended for low power EV microgrid applications and educational settings. The Atinverter V2 integrates various hardware and software subsystems centered around the ATMEGA328P microcontroller, enabling PWM-based sinusoidal power inversion, DC/AC voltage and current sensing, and embedded control features. Software development leverages a C++ object-oriented library and multiple Arduino-based modules to facilitate modular and scalable operation. …

Assessment Of The Imx7ulp Heterogeneous Soc For Use In A Next Generation Student Cubesat Obc, Lorenzo A. Pedroza

Master's Theses

CubeSats represent a rapidly evolving platform for space research, industry, and education, demanding increasingly sophisticated onboard computing solutions that balance performance, fault tolerance, size, weight, and power constraints. Although the design of the Cal Poly's CubeSat Lab's (PolySat) current On-Board Computer (OBC) keeps up with many of these factors, the demands of modern workloads like fine attitude determination will start to outpace available compute. While the selection of a more capable processor to address this would have traditionally resulted in increased energy usage, modern system-on-chip (SoC) architectures offer novel ways to trade available compute for power savings on-the-fly. With this …

Development Of A Novel Bio-Mimetic Ornithopter With Variable Flapping Angle, Geourg Kivijian

Master's Theses

From the beginnings of flight, flapping-winged flight has been a goal of many engineers to mimic and replicate. With gains in aerodynamic efficiency of flight and certain other favorable characteristics such as reduced noise, higher maneuverability, and surveillance opportunities in urban environments, flapping-wing aerial vehicle(FWAV) designs are consistently pursued in many corners of academia and industry. This thesis goes into the development of a flapping wing aerial vehicle with a Bio-mimetic novel drive mechanism that is cable-driven and can produce variable amplitude and frequency flapping stroke. Employing a Field-Oriented Control (FOC) Brushless Direct Current (BLDC) motor, paired with a bio-mimetic …

A Fault-Tolerant, Multi-Heap Dynamic Memory Allocator For Freertos, Garrett E. O'Neill

Master's Theses

The use of dynamic memory allocation presents a significant challenge for embedded systems, particularly in applications that require high reliability. The software controlling these systems needs to perform critical operations within strict timing constraints, and memory management plays a critical role in a system’s ability to meet these constraints. Dynamic memory allocation is inherently non-deterministic: if a task requests memory, it is impossible to predict how long it will take for the memory to be allocated. If a critical task were to rely on dynamically allocated memory, its execution could become stalled leading to a missed deadline and system failure. …

Leveraging Machine-Learning Algorithms In Two Car Crash Detection Systems On A Custom Dataset, Addison Jacob Sandvik

Master's Theses

Traffic accidents pose a significant threat to public safety, causing millions of deaths and injuries worldwide each year. While efforts to reduce accidents have seen limited progress in recent years, improving emergency response times through automated detection systems is a promising avenue for saving lives. This thesis describes the development of machine learning-based traffic accident detection systems, exploring both video classification and image detection models. The models are trained on a new dataset deemed the Cal Poly Traffic Accident Dataset, an extension of the existing Car Accident Detection and Prediction (CADP) dataset with a precise collision annotations. Two systems were …

Design, Fabrication, And Testing Of A Dual-Rate Spring System For Mountain Bike Frames, Lucas P. Grizzle

Master's Theses

The design of full-suspension mountain bikes is a careful balance of suspension kinematics, structural dynamics, and manufacturing optimization for the expected use case. A bike designed to excel in one area will likely exhibit reduced performance in others. This optimization problem is addressed by designing, integrating, and testing a dual-rate spring system within a fully custom frame. The dual-rate spring is fully decoupled from the rest of the suspension kinematics, providing designers with an additional parameter to achieve ideal suspension behavior. This is accomplished by placing a thermoplastic polyurethane (TPU) bushing in series with the rear shock. The influence of …

Statistical Time-History Response Of Mid-Story Isolated Structures In Linearized Elastic Conditions, Min Thit Khant

Master's Theses

This study presents a statistical analysis of the seismic demand of mid-story isolated structures in linearized elastic conditions. The assumed earthquake database consists of 228 ground motions recorded in California from earthquakes with magnitudes greater than 6. A three-degree-of-freedom modeling approach is adopted, and the seismic demands of the substructure, superstructure, and isolation system are determined for varying isolated mass and stiffness ratios. The seismic demand of mid-story isolated structures at the isolation level is expressed in terms of the response of an idealized isolated superstructure supposed to be on the ground, while the demands on the substructure and superstructure …

Evaluating Nanobubble-Enriched Water Treatments For Cleaning Stainless Steel Winery Tanks At The Gallo Winery Research Station In Livingston, California, Edgar Godoy-Garcia

Master's Theses

ABSTRACT

Evaluating nanobubble-enriched water treatments for cleaning stainless steel winery tanks at the Gallo winery research station in Livingston, California.

Edgar A. Godoy-Garcia

Sanitation of stainless steel wine storage tanks is a critical component of quality control in commercial winemaking operations. Ineffective cleaning can lead to microbial contamination, product spoilage, and safety concerns. Traditionally, wineries rely on manual scrubbing, chemical cleaning agents, and extensive water rinsing cycles to maintain sanitary tank conditions. However, these methods are resource-intensive and may pose risks to both workers and the environment due to chemical exposure and wastewater generation. In response to growing industry interest …

Model-Based Design Of Compressed Lithium-Metal Pouch Cell Battery Modules For Evtol Applications, Scott J. Stirling

Master's Theses

Batteries with higher specific energy and power are essential for extending the range and performance of electric vertical takeoff and landing aircraft (eVTOLs). Anode-free lithium-metal pouch cells offer strong potential at the cell-level but require high compressive pressures to enhance cycle life and discharge performance. These pressures necessitate heavier structural components, reducing packaging efficiency at the module level.

To evaluate this tradeoff, a full-factorial enumeration model was developed to explore viable module designs within a constrained packaging volume. The model scales subsystem masses, enforces design rules and material limits, and accounts for large (~20%) cell thickness changes during cycling.

Results …

Thermal Modeling Techniques For Additively Manufactured Porous Metals, Lucas D. Rambo

Master's Theses

Advances in additive manufacturing have enabled the creation of metallic components with tailored porosity, offering design flexibility for thermal, structural, and fluid transport applications. This thesis investigates the effective thermal conductivity (ETC) of porous Inconel 625 (IN625) and Inconel-ceramic composites (IN625-RAM2) fabricated by Laser Powder Bed Fusion (LPBF) using Elementum 3D’s PermiAM technology. Experimental measurements of thermal conductivity using the laser flash method are compared to numerical models built from micro-computed tomography data. Simulations were performed using both finite element (FE) and finite volume (FV) methods to evaluate thermal transport in real microstructures. The study investigates the effects of micro- …

Nonlinear Integral Control Schemes For A Cadence-Heartrate Process: A Matlab Exploration, Alexander G. Elliott

Master's Theses

Keeping one’s heart-rate within a specific range during a cardiovascular workout can be difficult due to many factors including variations in the exercise environment and changes in energy level. One’s heart-rate can be controlled by tuning the intensity level of the activity over time. This study focuses on the relationship between a runner’s cadence and their heart-rate and explores ways to control the heart-rate by adjusting the cadence. Previous work in this area modeled the cadence-heartrate plant as a first-order linear system, but this has been shown to be insufficient. This work improves upon previous research in this area by …

Development Of A Reaction Wheel System For Cal Poly’S Spacecraft Attitude Dynamics Simulator, Caleb Nalley

Master's Theses

The Cal Poly Spacecraft Attitude Dynamics Simulator (SADS) is an ongoing project to develop a system capable of simulating the attitude dynamics and kinematics of a rigid body in space. Actuations on the SADS are performed by reaction wheels, however the current reaction wheels have various issues that decrease system performance and are not independent of the SADS. The reaction wheel developed as part of this thesis will be designed to improve performance and set out design specifications tailored to the SADS, serve as an independent assembly that can be transferred to other systems, and provide a general outline for …

Study On The Application Of Smart Electric Meters For Secondary Voltage Protection, Jayaditya Sisodia

Master's Theses

The purpose of our research is to utilize PG&E’s Smart Meters installed across California to protect the Secondary Voltage delivered to the meter. This means detecting electrical faults between the utility’s distribution transformer and the installed Smart Meter. Our goal is to propose and implement various solutions through additional devices and protocols to detect and prevent these faults, communicate them with the meter, and forward fault information to the utility. A device will be designed to be installed on the transformer, detect faults, shut off power transmission, and communicate to the meter via fiber optic cable. Research will then be …

Multimodal Self-Folding Of Shape Memory Polymer Using Laser Induced Graphene, Liam Harrison Drew

Master's Theses

Shape memory polymers (SMPs) can undergo programmed shape transformations when heated above their glass transition temperature (T_g), enabling actuation through stimuli such as infrared (IR) radiation and Joule heating. These materials are promising for deployable systems and soft robotics due to their lightweight structure and elimination of traditional mechanical components. While IR-based actuation is simple and low-cost, it lacks precision in uncontrolled environments. Joule heating offers improved control but is often limited by conductive ink properties such as thickness, stiffness, or poor adhesion. This work introduces a novel method for multimodal SMP actuation using laser-induced graphene (LIG) transferred …

Effect Of Household Oil Contamination And Agricultural Soil Contamination On Phyllosilicate Nanocatalyst Performance During Pyrolysis Of Polyolefins, Joey Velasquez

Master's Theses

The effect of household oil and agricultural soil contamination on catalyst performance during polyolefin pyrolysis was simulated on mixed virgin plastic pellets by evaluating contamination influence on mixed plastic degradation temperatures. Three phyllosilicate nanocatalysts including Fulcat435, Fulcat22F and Y-Zeolite were evaluated in this work based on a literature review of catalyzed plastic pyrolysis and these catalysts’ ability to lower plastic decomposition temperature by 50 °C – 100 °C. These findings were confirmed in this research through thermogravimetric analysis of a polyolefin mixture and further developed in furnace experiments containing household oil and agricultural contamination. Household oil contamination deactivated each of …

Open Source Asic Design Curriculum, Francisco Wilken

Master's Theses

The ever-growing importance of Application-Specific Integrated Circuits (ASICs) in a high-compute world necessitates that college graduates entering the workforce are well prepared to design them. This thesis details the design of novel ASIC curriculum, using open source tools to teach at the undergraduate level. By moving to a higher level of abstraction than classical transistor-focused coursework, chip design material can be made accessible earlier in an undergraduate degree. Additionally, open source tools provide a powerful, free, and portable platform for students to create their own designs, solving assignments focused on industry readiness. Finally, this thesis studies the results and challenges …

Remote Monitoring And Control Of Protection Relays Via Programmable Logic Controller, Rio Mcgown-Kauffman

Master's Theses

The purpose of this study is to explore the ability of a programmable logic controller (PLC) to wirelessly monitor and control power protection relays. The technologies surrounding power protection and industrial automation are ever evolving and have developed significantly in recent history. Industrial power applications call for consistent condition monitoring and status updates for various high-importance components. The high-importance components have power protection schemes that are managed by digital relays to trip circuit breakers in fault or unsafe operating conditions. The smart relays have a wide range of capabilities, including communications. Cal Poly assembled a collection of relays from Schweitzer …

Modeling Battery Energy Storage Systems To Study The Effects Of Battery Chemistry And Operation On Power Quality, Lin E. Knudsen

Master's Theses

This thesis studies the impacts of battery chemistry (specifically lithium-iron phosphate, sodium-ion, and solid-state), AC voltage, battery size, charging mode, state of charge (SOC), active power draw, and power factor on the power quality of a Battery Energy Storage System (BESS). For harmonic evaluation, the metrics provided by the IEEE Standard 519 are used as a guideline to quantify voltage and current harmonics. A comprehensive MATLAB Simulink using Simscape Electrical is used to develop and simulate the models for the battery, DC-DC converter, AC-DC converter, and the grid. A total of 57 simulation cases varying the BESS factors are performed, …

Hands-Free Balance Protocol And Development Of An Iphone App For Self-Assessment, Jacob Matties

Master's Theses

For many clinical populations, the measurement of balance is a critical task. Previous studies have agreed that smartphone IMUs provide a valid measure of balance that can be significantly correlated with force plate measurements and is sensitive enough to distinguish between various balance poses, but many balance assessment protocols require uncommon equipment or the use of hands during assessment. These limit accessibility of balance assessment. To eliminate the need for hands or any additional equipment, this study assessed the use of a smartphone recording the root mean square of 3D acceleration magnitude. The goal of the study was to determine …