Mechanical Engineering Commons^™

Experimental Study Of Gas-Dynamic Heating In Hartmann-Sprenger Tubes For Rocket Engine Ignition, Jacob T. Huff

Master's Theses

Ignition systems for chemical rocket engines typically rely on hypergolic propellants or auxiliary electrical hardware to supply the energy required to initiate combustion. The resonance igniter is a simple and robust alternative to these conventional methods, capable of inducing autoignition of non-hypergolic propellants without an external ignition source. At the core of this concept is the Hartmann-Sprenger Tube (HST), a device in which a high-velocity jet of gas impinges on a resonance cavity. This interaction establishes self-sustaining gas oscillations within the cavity that heat the propellants to their autoignition temperature. To facilitate the development of a functional resonance igniter at …

Integration And Testing Of A Quadruped Robot With Ros2, Jeremy S. West

Master's Theses

The Cal Poly Legged Robotics Group has been developing research and teaching platforms for agile legged robotics since 2020. These platforms are expected to provide students with opportunities to develop complete legged-robot systems from low-level control to advanced robotics tasks such as motion planning and decision making. However, the current prototyped quadruped robot lacked the software and sensing capabilities for high-level quadrupedal gaits and advanced robotic research.

To address these challenges, this project developed Switch, a robotic platform that builds upon the previous BRUCE platform with significant hardware and software upgrades. Switch features a modular design that allows individual software …

Efficient Thermal Design Of Data Centers, Keats M. Baggett, Andrew Ergood, Colin Brace, Jack Zilligen

Mechanical Engineering

Our sponsor needs a way to categorize and quantify the top 3 colocation center sites based on a series of criteria for given power specs. The sponsor also needs a single innovative cooling method to meet thermal and power requirements while also being manufacturable at scale. This device must also be able to interact with the given Colocation Heating Ventilation and Air Conditioning (HVAC) system. This design will be tested to provide insight and data that will be applicable to further the development of colocation center cooling. This project will be executed by the Cal Poly senior project team and …

Aerospace Fastener Installation Tool, Anthony I. Berghout, Matthew K. Eggers, Liam Dunsmore, Jose Pardo

Mechanical Engineering

Contamination, particularly in aerospace manufacturing environments, is a significant concern, especially with fastener designs that incorporate torque-rated breakaway pieces for easier installation. These breakaway pieces are also known as pintails. Howmet has tooling that can collect loose pintails during installation, but they have small capacities and are not ergonomic for aerospace technicians. Their current need is for a light and ergonomic tool capable of installing a wide variety of Ergo-Tech® fasteners while having a large capacity to collect pintails and improve aerospace manufacturing methods. For this Critical Design Stage, we have finalized a design that allows Pintails to pass through …

2-Axis Solar Panel Tracker, Danica Wong, Oliver Barnaal, Anton Orme

Mechanical Engineering

Solar panels generate energy from sunlight. To do this it’s important that they remain pointed at the sun throughout the day. The Cal Poly Micro Grid Lab runs a class that uses a student made solar panel and tracking mount as an instructional tool. This project is beginning to show signs of wear from outdoor use and is unable to run without constant input due to some significant design flaws. The lab needs a new version of the mount to be made that is significantly more reliable and easier to use.

Edwards Lifesciences: Esheath+ Scoring Automation, Tony Lee Avina, Kirth Hirth, Charith Sunku, Humberto Salazar-Banuelos

Mechanical Engineering

Due to a non-disclosure agreement with our sponsor, Edwards Lifesciences, the contents of the report have been omitted.

Kinetic, Wind-Driven Metal Sculpture, Irene Songhee Han, Aiden Brown Largay, Madeline Vang Xiong

Mechanical Engineering

The Interdisciplinary Senior Design Team “Flying Flora” from Cal Poly’s College of Engineering has been tasked with designing and building a wind-driven dynamic metal sculpture for the San Luis Obispo Botanical Garden. The botanical garden wants to fill a large, centrally located vacant space with a kinetic sculpture to attract and welcome visitors. The final design, as approved by the garden’s directors, features a large metal California poppy below a stained-glass and metal butterfly. The flower rotates smoothly in typical wind conditions, drawing the attention of visitors to the sculpture. The butterfly is stationary, positioned at an angle from the …

Aluminum Boat Rotation Fixture, Kevin W. Heiskell, Nathaniel M. Conway, James S. Knowles, Austin J. Kehl

Mechanical Engineering

Aluminum fishing boats are widely used for various water-based activities, including fishing, transportation, and recreation. Their lightweight construction makes them ideal for maneuverability, particularly in regions like Australia. However, the manufacturing process presents challenges, specifically the need to weld both the interior and exterior seams of the hull. As the boat’s weight increases during assembly, flipping it becomes difficult and potentially hazardous. Traditional methods such as cranes or forklifts are inefficient and pose safety risks. To address this, our team developed a rotating fixture that secures the boat at two connection points, one at the bow and one at the …

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 …

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 …

In-Situ Defect Detection In Selective Laser Melting Using Convolutional Neural Networks, Ethan Gaigalas

Master's Theses

This thesis develops and trains a convolutional neural network (CNN) to classify defects in metal parts produced by selective laser melting (SLM) using acoustic emission (AE) data. The model successfully identified porosity and standard build layers with high accuracy but consistently struggled to classify lack of fusion (LOF) defects, regardless of input type, normalization, or class count. These results suggest that while AE signals contain distinguishable features for certain defect types, LOF signals may be too subtle or inconsistent for reliable detection. The study addresses the ongoing challenge of in-situ quality monitoring in metal additive manufacturing, where defects like cracks, …

Cryogenic Fuel Delivery System, Carter Josef, Reilly Humphreys, Joseph O'Connor, Nick Spreen

Mechanical Engineering

This project presents the design and validation of a cryogenic fuel delivery system aimed at enabling sustainable aviation through hydrogen fuel vaporization. Developed by a team of senior mechanical engineering students at Cal Poly and sponsored by Boeing, the system utilizes atmospheric air to vaporize liquid nitrogen, used as a stand-in for hydrogen, via forced convection heat exchangers, eliminating the need for engine-supplied heat and reducing parasitic loads. A feedback loop and turbine component are integrated to regulate pressure and recover energy, respectively. A benchtop prototype was built and tested to evaluate system performance, with results closely aligning with analytical …

Conversational Social Robot, Julianna M. Christopoulos, Mackenzie Goldman, Cece E. Hujanen, Jared Hunter

Mechanical Engineering

Background: Social robots are used in various settings to reduce burden on human workers and expand opportunities for people in need of assistance.

Challenge: Design a humanoid robot head and torso capable of holding conversations and interacting with a user using a LLM and motion. Conversations are limited to discussing Cal Poly resources and opportunities with visitors to the Bently Research Center on campus.

Scitechatorium, Olivia Lafferty, Yvonne Brien Miller, Colton Swinth, Savannah Pinheiro, Gage Heinze

Mechanical Engineering

Bellevue Santa-Fe Charter School (Bellevue) is a K6th grade public charter elementary school in Avila Beach, California. The primary focus at Bellevue is fostering unique learning experiences, empowering students through project-based learning, and engaging students in creative endeavors. Following these themes, the school has allocated space and funding for an on-campus science and technology museum known as the SciTechatorium. The museum is currently open during students’ lunch period, providing interactive displays on concepts in human biology, nature and wildlife, physics, and electronics. Bellevue’s K-6th grade science teacher, Christian Strauli, and Bellevue parent volunteers are primarily responsible for the museum’s upkeep …

Evoque Delivery System Fixture Optimization, Jack Ellis, Florence Duff, Noah Dunsmore, Timothy Hunter, Rafael Castillo

Mechanical Engineering

No abstract provided.

3d Printed Fixed Wing Aircraft Competition, Sidney E. Long, Mitchell Heise, Jack Bride, Daniel Salinas

Mechanical Engineering

Cal State LA and Arlington University, Texas are hosting the same 3D printed, fixed wing aircraft competition for 2025. Cal Poly requires a competitive plane that can adhere to each rule and be piloted remotely to achieve the longest time in the air. The plane must utilize solely 3D printing technology for the wings, body, and all other structures. The only off-the-shelf components can be the motor and electronics, as well as mechanical devices such as hinges.

Combustion Liner Optimization, William Weeks, Daniel Reed, Isaac Trull

Mechanical Engineering

Solar Turbines provides gas power generation solutions, focusing on gas turbine engines and compressors. The Gas Turbine Products Engineering (GTPE) team at Solar Turbines needs a way to efficiently and cost-effectively maintain the combustion liner of the Taurus model gas turbine at or below the cold-side temperature target. The current system involves a manufacturing process with ergonomic concerns and uncertain cooling effectiveness.

To address this, our team proposed a new combustion liner system featuring impingement cooling. We provided Solar Turbines with heat transfer models of both the existing and proposed designs, demonstrating improved cooling performance. Additionally, a prototype of the …

License To Drill, Gabrielle Noemi Orlando, Alexcias Olga Meeks, Dayana Guadalupe Gonzalez, Mark Dahmen

Mechanical Engineering

The goal of this project is to provide the student machine shops with an updated License to Drill (LTD) certification training, formally known as the Red Tag. The current training has two key components: a preliminary Canvas course and an in-person training with a safety tour, safety quiz, and a hands-on project. Currently, the hands-on project is outdated and unengaging. Thus, the primary focus is to replace it with an inspiring and memorable project, which includes written and visual instructional content on how to make it. The Canvas will thus be updated, a new instructional video will be created, and …

Pendulum Wave Generator, Abigail Jocelyn Romero, Paul Staley, Wendy Dong, Kyle Schumacher

Mechanical Engineering

The Cal Poly Mechanical Vibrations Laboratory (Vibes Lab) serves to educate and excite students about mechanical vibrations through hands-on experiments. While the lab contains several relatively complicated technical experiments, it lacks simple demonstrations with immediate visual interest to appeal to audiences with less technical backgrounds. Because of this, faculty desired a fun and interactive demonstration project that could be operated with no prior training. The project chosen for this is a Pendulum Wave Generator which is a set of multiple pendulums with differing lengths that combine to create complex and observable patterns over time. This project was completed by a …

Adaptive Riding Mount Block, Lucas R. Reynolds, Lukas M. Moreau, Patrick J. Michael, Jandre D. Lafradez

Mechanical Engineering

Professor Sarah Stewart from the Animal Science Department at Cal Poly seeks to develop a solution to help people with disabilities mount horses. Users need a mounting block that can bring them closer to the horse’s back to ease mounting. The current system, consisting of two plastic two-step blocks, is inadequate—unstable, too small, and inaccessible for wheelchair users.

The required solution must meet several key specifications: it should accommodate at least three people standing side by side, be sturdy enough to support their combined weight, and remain stable on rugged terrain like gravel or sand without tilting or sinking. Additionally, …

Lidss Raft Battery Pack Integration, Jack Maxwell, Vincent Stevens, Matthew Hoodmaker, Colin Flanders

Mechanical Engineering

Lawrence Livermore National Laboratory is a critical member of the United States Department of Defense. Their Independent Diagnostics Scoring System (LIDSS) uses rafts that operate in the ocean to collect missile test data. Several times a year, the United States will test their Inter-Continental Ballistic Missiles by launching them into the ocean near the Marshall Islands. This is where the LIDSS rafts collect their test data. Our project was centered around re-designing the battery pack used by the rafts. The current battery pack design experiences water ingress problems and is difficult to access. Our re-designed battery pack is waterproof to …

Foot Pedal Assistive Device, Julian Rubinstein, Connor Jessen, Isabelle Utsler, Sydney Alexander

Mechanical Engineering

Individuals with lower-limb mobility problems may have trouble accurately locating the pedals of a three-pedal manual transmission car, and some medical conditions cause individuals to fatigue more quickly when driving. This project aimed to create a device that assists in locating the user’s feet, indicates to the user which pedals are currently in use, and provides a visual and physical warning if they are not in the correct place. The project sponsor, Alan Keizer, is the primary stakeholder in this project. This device will be designed specifically for Alan’s Subaru BRZ and will address Alan’s specific lower-limb mobility issues that …

Van Accessibility, Ann Larson, Camelia Anne Noureddine, Stephanie Rose Ruzicka, Kayla Joanne Gowey

Mechanical Engineering

The SLO Achievement House provides resources and activities for their clients, including daily trips to different parts of the community, to keep their clients connected to society. These trips require the clients, many of whom struggle with general mobility and strength, to step up to the high entrance of a van or company car. This daily activity poses a challenge both physically and emotionally for the clients. The current solution utilizes commercially available step stools, which lack handrails, overall stability, and adequate step depth. The Achievement House needs a stool or ramp tailored to their client’s needs and their specific …

7lr-C Upper Limb Dancing Prosthetic, Victor Ochoa, Zoe Kelemen, Ged Mulingtapang, Marley Paltiel

Mechanical Engineering

Ella Wallis, a student at Cal Poly and performer in the Cal Poly Drag Club with a trans humeral upper limb difference, wants a prosthetic device that allows for a large range of motion and high degree of articulation to help them better dance in the style of voguing, allowing them to express themselves further while performing. The prosthetic arm is body-driven and relies on momentum to reposition. It attaches to the user through a harness, which is clipped to a socket with elastic straps to not impede the shoulder’s range of motion. The design contains urethane resin, aluminum, stainless …

Drone Package Delivery System, Aiden Tyler Sim, Ryan Anders O'Toole, Matthew Karl Wyant, James Shaw Glanville

Mechanical Engineering

In response to the demands of the 2025 C-UASC (California Unmanned Aerial Systems Competition), our team developed an autonomous drone payload delivery system capable of two distinct delivery modes: a precision-controlled descent and a high-speed aerial drop. Designed for modular integration with UAV platforms, the system prioritizes reliability, accuracy, and simplicity under desert environmental conditions. Our solution features a custom winch mechanism with a programmable stepper motor, a passive mechanical hook for tension-based release, and a servo-actuated trapdoor for high-altitude drops. The design was extensively tested for structural integrity, motor torque requirements, drop precision, and electronics reliability—culminating in a robust …

Llnl Raft Flash Pole Redesign, Jack Stangel, Evan Wolfson, Jake Borden, Alexander Meeter

Mechanical Engineering

During research exercises in the ocean, Lawrence Livermore deploys a fleet of rafts outfitted with flash modules affixed to tall poles (in tandem called flash poles) that flash while a photo is taken to act as datums for data collection. The current flash pole design that the LIDSS (Lawrence Livermore Independent Diagnostic Scoring System) team uses is too short to be visible in high seas, not mechanically suited to be made taller, too susceptible to the elements and blunt impact and too difficult to service. We aim to solve these issues.

Torsional Vibration Kit Simulator (Tks), Joseph Thachet, Luca Lawson, Ryan Ota, Otis Mcloughlin

Mechanical Engineering

The goal of this project was to create torsional vibration on a shaft while limiting axial and radial vibration. To do this an eddy current brake was used to slow down a rotating shaft. The electromagnets used to create the eddy currents are able to be turned on and off at a frequency produced by a function generator. This power cycling of the electromagnets creates an alternating braking force thereby inducing torsional vibration while limiting the other two vibration types

Uv Vessel Hoist Scope Of Work, Quinn J. Horak, Harvey Perkins, Andrew A. Osborn, Mikayla H. Nieman

Mechanical Engineering

The San Luis Obispo Wastewater Treatment Plant uses ultraviolet (UV) tubes to purify water. These tubes are cleaned by an internal wiping mechanism that must be removed for servicing and replacing damaged tubes. Currently, this is accomplished by using an engine hoist, but this method requires a large amount of effort and is not safe. Technicians have requested a new method of lifting wiper mechanisms that is safer, faster, and easier to use than their current method.

To solve this problem, we have developed a design that consists of a custom gantry crane with a hoist on a trolley. The …

Trailer Transport System For Multi-Ton Bins, Joanna Lizbeth Bendy, Kevin Matthew Creel, Annelise Vaara Cuneo, Hugo Alonso Valdez

Mechanical Engineering

This project aimed to improve the process of transporting 10,000-pound industrial waste bins. The current method for relocating these bins poses safety risks and requires significant manual effort. This project presents a conceptual solution that enables a single operator to efficiently and safely move roll-off bins using a custom-designed trailer system. The design incorporates three main subsystems: a trailer frame, an integrated winch system, and an off-the-market puller device to guide and secure the bin during transport. Two scaled proof-of-concept prototypes were fabricated to evaluate key aspects of the system's functionality. Testing and analysis suggested that the system is viable …

Brush Seal Cycling Test Rig, Angelo J. Reis, Neil M. Bedagkar, Max A. Soury, Eoin K. Lenham

Mechanical Engineering

To prevent backflow from the high pressure compressor stages of their gas turbines to lower pressure regions, Solar Turbines utilizes brush seals along their driveshafts. Due to manufacturing limitations, no shaft is perfectly symmetric about its rotating axis, leading to orbiting that creates asymmetric friction on the shaft through rubbing. With this biased application of friction comes a hotspot on one side of the shaft, causing bowing of the shaft and cascading into an amplified vibrational response. Our goal is to gather data on this phenomenon and offer a potential solution.