Mechanical Engineering Commons^™

Structural Integrity Assessment Of Shell And Tube Heat Exchanger Tube-To-Tubesheet Joints Fabricated Using Conventional And Nonconventional Manufacturing Processes, Dinu Thomas Thekkuden

Dissertations

Tubes and tubesheets, integral components of shell and tube heat exchangers, have an important role in the functioning of the heat transfer between the tube-side and shell-side fluids. Tube-to-tubesheet joints act as a barrier to prevent the mixing of the transfer fluids in addition to aiding the structural rigidity of the shell and tube heat exchanger. Tube expansion process and welding are the manufacturing processes used for fabricating structurally rigid tube-to-tubesheet joints. Many instances of tube-totubesheet joint failures leading to the complete collapse of the heat exchangers demand attention to assessing the mechanical and metallurgical characteristics of tube-totubesheet joints fabricated …

Heat Transfer Analysis Of Microchannels Heat Sink With Sidewall Fins, Ahmad Ala Eddin Rahhal

Theses

This study aims to investigate Microchannel Heat Sinks with side wall fins through a model-based approach. The primary objective of the project is to design and analyze the thermal performance of straight Microchannel Heat Sinks with square and triangle-shaped fins on sidewalls. To examine their performance, a computational fluid dynamics (CFD) simulation study is conducted using the ANSYS Fluent software. The study starts by creating a CAD model of the heat sink and then analyzing its thermal properties with the ANSYS Fluent software. From the CFD simulation study, numerical results are obtained for different operational and geometrical conditions. The study …

Sharprazor: Automatic Removal Of Hair And Ruler Marks From Dermoscopy Images, Reda Kasmi, Jason Hagerty, Reagan Harris Young, Norsang Lama, Januka Nepal, Jessica Miinch, William V. Stoecker, R. Joe Stanley

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Background: The removal of hair and ruler marks is critical in handcrafted image analysis of dermoscopic skin lesions. No other dermoscopic artifacts cause more problems in segmentation and structure detection. Purpose: The aim of the work is to detect both white and black hair, artifacts and finally inpaint correctly the image. Method: We introduce a new algorithm: SharpRazor, to detect hair and ruler marks and remove them from the image. Our multiple-filter approach detects hairs of varying widths within varying backgrounds, while avoiding detection of vessels and bubbles. The proposed algorithm utilizes grayscale plane modification, hair enhancement, segmentation using tri-directional …

Development Of Mirror Flexures For Use In The Muvi Instrument, Colin W. Harrop

Master's Theses

The Miniaturized Ultraviolet Imager (MUVI), is a compact wide field UV imaging instrument in development at UC Berkeley Space Sciences Laboratory and Cal Poly, San Luis Obispo. MUVI is designed to fit in a 2U CubeSat form factor and provide wide field, high resolution images of the ionosphere at far ultraviolet wavelengths. This thesis details the design and analyses of MUVI’s deployable cover mirror mounting flexures. Three different flexure geometries were evaluated, an optimal candidate was determined based on a number of criteria including isolation of vibration and stress to the mirrors, manufacturability and cost. The design of the flexure …

Hybrid Fes-Exoskeleton Control: Using Mpc To Distribute Actuation For Elbow And Wrist Movements, Nathan Dunkelberger, Jeffrey Berning, Eric M. Schearer, Marcia K. O'Malley

Mechanical Engineering Faculty Publications

Introduction: Individuals who have suffered a cervical spinal cord injury prioritize the recovery of upper limb function for completing activities of daily living. Hybrid FES-exoskeleton systems have the potential to assist this population by providing a portable, powered, and wearable device; however, realization of this combination of technologies has been challenging. In particular, it has been difficult to show generalizability across motions, and to define optimal distribution of actuation, given the complex nature of the combined dynamic system. Methods: In this paper, we present a hybrid controller using a model predictive control (MPC) formulation that combines the actuation of both …

Rocketing Ahead: Basketball Player Plans To Apply Mechanical Engineering To Aerospace, Rocky Garza Jr.

Black History at St. Mary's University - 2025 Collection

Student Emmanuel Ewuzie is in a unique position as he is not only a successful athlete on the court, but also a successful student with aspirations in pursuing a career in aerospace engineering. While basketball and aerospace engineering may seem like they might not have many commonalities, Ewuzie can leverage his education and on-the-court experiences to become a successful scholar and leader. Coach Buddy Meyer and Associate Professor Juan Ocampo are among many people who vouch for Ewuzie’s ability to lead by example, while also having the drive to pursue goals that not only lead to personal success but also …

Improving Future Vehicle Fuel Economy And Operational Design Domain Through Novel Data Pipelines, Kyle James Carow

Masters Theses

Modern automobiles have greatly advanced in recent years, with technological developments that enhance performance, safety, and comfort. However, there is still much room for improvement. Today’s vehicles are heavily reliant on the combustion of fossil fuels, proven to be harmful for the environment on both a local and global scale. In addition, the safety benefits of autonomous vehicles and advanced driver assistance systems are not yet fully realized due to the limited operational design domain of these technologies. In this research, these needs are addressed through the development of two novel data pipelines. In the first study, a novel methodology …

Nautilus Rov Robot Manipulator, Dana Stefanides, Jenny Huynh, Andrew Stewart, Steven Reimer, Andrew Nguyen, Rebecca Walters, Matt Hayes

Interdisciplinary Design Senior Theses

Global warming and climate change are prevalent issues in today’s society. As a result, research in the ocean, our world’s biggest ecosystem, is imperative in efforts to protect the environment. Santa Clara University’s Robotic Systems Lab contributes to this field through work and developments on remotely operated vehicles (ROVs). An existing ROV system called Nautilus consists of a robot arm, end effector, and storage system in order to collect various types of sediments at a depth of 300 feet. However, the previous system does not meet that requirement. In direct collaboration with researchers within the Monterey Bay Aquarium Research Institute, …

Thermal Boundary Condition Effects On Local Supercritical Co2 Heat Transfer Trends In Tubes, Nicholas C. Lopes

Doctoral Dissertations and Master's Theses

Supercritical carbon dioxide (sCO2) is a promising heat transfer fluid for the refrigeration and power generation industries due to its unique thermal properties and low environmental impact. To understand it as an alternative to traditional working fluids, the thermophysical and heat transfer phenomena of sCO2 are often studied using simplified geometries (tubes). Focus has been placed on investigating averaged heat transfer trends under an array of flow conditions with either a constant wall heat flux, constant wall temperature, or conjugate thermal boundary condition. Less emphasis has been placed on studying local sCO2 heat transfer developments. Tubular sCO2 numerical models that …

Experimental And Numerical Analysis Of A Commercial Phase Change Material Melting At Different Inclinations, Andrew Heiles

Doctoral Dissertations and Master's Theses

The study of various phase change materials (PCM), experimentally and numerically, have been completed over the past several years to address their feasibility and potential when used in latent heat thermal energy storage (LHTES) systems for a variety of potential applications. Previous studies have investigated changes into the type of PCM used in the system as well as the system configuration, ranging from boundary conditions to internal and external geometries and orientations of the system. The present study focused on conducting experiments at different inclination angles and isothermal wall temperatures with the organic PCM PureTemp37, and continued with a numerical …

Assessing High Dynamic Range Imagery Performance For Object Detection In Maritime Environments, Erasmo Landaeta

Doctoral Dissertations and Master's Theses

The field of autonomous robotics has benefited from the implementation of convolutional neural networks in vision-based situational awareness. These strategies help identify surface obstacles and nearby vessels. This study proposes the introduction of high dynamic range cameras on autonomous surface vessels because these cameras capture images at different levels of exposure revealing more detail than fixed exposure cameras. To see if this introduction will be beneficial for autonomous vessels this research will create a dataset of labeled high dynamic range images and single exposure images, then train object detection networks with these datasets to compare the performance of these networks. …

Additive Manufacturing For Phase Change Thermal Energy Storage And Management, Thomas B. Freeman

Doctoral Dissertations and Master's Theses

Phase change materials can enhance the performance of energy systems by time shifting or reducing peak thermal loads. Certain electronic devices such as batteries, laser systems, or electric vehicle power electronics are highly transient and require pulse heat dissipation. Heat sinks, or thermal management devices made of a phase change material can absorb large heat spikes while maintaining a constant temperature. Additive manufacturing techniques hold tremendous potential to enable co-optimization of material properties and device geometry, while potentially reducing material waste and manufacturing time. Recently, a few efforts have emerged that employ additive manufacturing techniques to integrate a phase change …

Neural Network Fusion Of Multi-Modal Sensor Data For Autonomous Surface Vessels, David J. Thompson

Doctoral Dissertations and Master's Theses

Autonomous surface vessels (ASV) can potentially improve the safety of vessels traditionally operated by humans. Despite advancements in autonomous on-road vehicles, many of these advancements have yet to be realized for ASVs. This is primarily due to lacking ASV sensing platforms and public datasets for ASV-based perception research. To that end, this dissertation demonstrates the design of a synchronized multi-modal sensing platform for ASVs utilizing GPS/INS, LiDAR, LWIR cameras, HDR camera, and high-resolution cameras. The sensing platform is designed to maximize the overlap of sensors for multi-modal research and provides accurate intrinsic and extrinsic calibration between each sensor. Furthermore, the …

Portable Drinking Water Cooler And Dispenser, Gustavo Hernandez-Lerena, Erik Torres, Caleb Francis Parham, Terry Leung

Mechanical Engineering

This document serves as the comprehensive report for the testing and building for the Portable Water-Cooling System by team AquaCool. Team AquaCool is comprised of four mechanical engineers with a passion to help the agricultural industry in their efforts to keep the health of the workers at their peak. The four engineers who partook in helping the farm workers are as follows: Caleb F. Parham, Erik Torres, Gustavo Hernandez-Lerena, and Terry Leung. To reduce the risk of heatstroke and other unwanted effects from the harsh working conditions during summer, a small and portable system was built to help in the …

Simulating Steam Jets Due To Rapid Plate Tectonics: A Computational Fluid Dynamics Analysis, Emilie Hatton

Senior Honors Theses

According to the Bible's account of earth's physical history, the majority of geological change from creation to the Ice Age is a consequence of the global Flood cataclysm described in Genesis 6-8. The changes included large-scale tectonic activity, recycling all pre-Flood ocean floor into the mantle, and generating all present-day igneous ocean floor by seafloor spreading at mid-ocean rift zones. Along the middle of these zones, strips of newly formed seafloor were present near the melting temperature of basaltic magma. Above these strips of extremely hot rock, intense jets of steam would almost certainly form. This research seeks to investigate …

Droplet Capture In A Fiber Array, Karl Cardin, Christophe Josserand, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Droplets interacting with fiber arrays is ubiquitous in nature, textiles, microelectromechanical devices, and fog harvesting. The phenomena of droplet impact on an equidistant array of fibers is experimentally investigated. Drop tower tests are performed to characterize the droplet dynamics in the absence of the effects of gravity which could deform fibers and bias equilibrium configurations. Results show that contact line dissipation is largely responsible for arresting the droplet. Additionally, the penetration length is affected by fiber flexibility. A model is developed predicting the droplet penetration dynamics which shows good agreement with experiments.

Jpl Robotic Avionics & Sensor Kit (Rask), John Helzer

Honors Program: Senior Projects (Public)

No abstract provided.

Plasmon Enhanced Quantum Properties Of Single Photon Emitters With Hybrid Hexagonal Boron Nitride Silver Nanocube Systems, Mohammadjavad Dowran, Andrew Butler, Suvechhya Lamichhane, Adam Erickson, Ufuk Kilic, Sy_Hwang Liou, Christos Argyropoulos, A. Laraoui

Department of Mechanical and Materials Engineering: Faculty Publications

Hexagonal boron nitride (hBN) has emerged as a promising ultrathin host of single photon emitters (SPEs) with favorable quantum properties at room temperature, making it a highly desirable element for integrated quantum photonic networks. One major challenge of using these SPEs in such applications is their low quantum efficiency. Recent studies have reported an improvement in quantum efficiency by up to two orders of magnitude when integrating an ensemble of emitters such as boron vacancy defects in multilayered hBN flakes embedded within metallic nanocavities. However, these experiments have not been extended to SPEs and are mainly focused on multiphoton effects. …

Robotic Arm Extrusion End Effector, Nicholas Viamin, David Blouin, Savannah Hunt, Nico Figueroa

Interdisciplinary Design Senior Theses

This senior design project aims to enhance the capabilities of the Rotrics AIO Desktop Arm (Dexarm) by designing and implementing an extrusion device capable of smooth and consistent extrusion for 3D printing applications. The project focused on ensuring safety, affordability, and ease-of-use for users, while achieving precise control over the extrusion process. Various mechanical and electrical components were carefully selected to ensure compatibility with the Dexarm and to provide optimal performance. To maintain safety, extensive testing and risk assessments were conducted to minimize any potential hazards associated with the extrusion process. To achieve smooth and consistent extrusion, precise control mechanisms …

Spin Mediated Topological Black Hole In Acoustic Metamaterials Near Dirac-Like Cone Frequencies., Mustahseen Mobashwer Indaleeb

Theses and Dissertations

A unique bulk-boundary distinction and acoustic topological phenomena is discovered and explained in this dissertation. The overall objective was to discover the hidden physics, dynamic and mechanics of acoustic wave behavior that causes the formation of extremely rare ‘Topologically protected Black Hole’ (TBH) in acoustic microarchitecture metamaterials. This behavior is immensely valuable for numerous mechanical and civil engineering applications where acoustic insulators are required to create sound-free or vibration-free exterior surfaces. On the other hand, to contain the energy within the structure, for impact mitigation and energy absorption in vehicles, space crafts, aircrafts, and civil infrastructures such materials will be …

Experimental Observation Of Sphere Symmetric Isolated Single Droplet Combustion In A Converging Channel, Mason Carrington Williams

Theses and Dissertations

Spherically symmetric isolated single droplet combustion has been observed mainly in microgravity conditions. This study sought to determine if spherically symmetric combustion can be produced in a lab-scale experiment using flow acceleration to counteract the effects of buoyancy. The experiment was conducted in a converging channel that decreased in width along its length to accelerate the flow and limit the formation of a boundary layer. The rate at which the area decreased was governed by the initial velocity condition set at the channel inlet.

The droplets were generated using a piezoelectric actuator which forced fuel out of an injector with …

Hydrothermal Liquefaction Of Saccharina Latissima For The Production Of Biofuel, Mayokun A. Oke

Mechanical Engineering Theses

We performed hydrothermal liquefaction of brown macroalga (Saccharina latissima) in the presence of homogenous and heterogenous catalysts such as KOH, Na₂CO₃, Pd/C, HZSM-5, Ce/HZSM-5, and Ni/SiO₂-Al₂O₃ in hot compressed water, to investigate their effects on product yield and composition in the biocrude. To investigate hydrocarbon production, we used methanol as co-solvent (methanol-to-water 1/4 vol.%) and as the only liquefaction solvent. We carried out the experiments in a batch reactor at 330^oC and 120-130 bar, and varying temperature, algae-to-water ratio, residence time, and pretreatment method. The biocrude yields …

Adaptation Of High Spatio-Temporal Resolution Weather/Load Forecast In Real-World Distributed Energy-System Operation, Amir Ali Safaei Pirooz, Mohammad J. Sanjari, Young Jin Kim, Stuart Moore, Richard Turner, Wayne Weaver, Dipti Srinivasan, Josep M. Guerrero, Mohammad Shahidehpour

Michigan Tech Publications, Part 1

Despite significant advances in distributed renewable energy systems (DRES), the technology still faces several substantial challenges that prevent the large-scale adoption of these systems into a country’s energy sector. The intermittency of renewables, uncertainties associated with real-time multi-horizon weather and load forecasts, and lack of comprehensive control systems are among the main technical and regulatory challenges for the real-world adoption of DRES. This paper outlines the current state of knowledge in the real-world operation of DRES and also describes pathways and methodologies that enable and facilitate the uptake of DRES in a country’s energy sector.

Soft Shell Helmet Cover, Jo Espiritu, Caleb Chiang, Jay Laborin, Serry Srouji, Mathew Franke

Mechanical Engineering Senior Theses

Lattice structures usage for attenuation is growing in popularity as 3D printing methods allow for the easier production of complex structures. The application of these impact attenuators allows for wider applications that can lead to better products in sports such as football to prevent head trauma. In this paper, we aim to design and test lattice structures to determine a lattice model that best prevents impacts through drop and compression testing to provide an outer layer of protection for football players. Initial validity through finite element analysis provided four potential lattice structures with a single parameter. Physical testing determined the …

Flexible Materials And Applications For Wearable Sensors, Brock Ferrari

Senior Honors Theses

This literature review aimed to address the limitations of rigid wearable sensors in the medical community by investigating the development of flexible materials for remote health monitoring. A keyword search was conducted on Google Scholar, PubMed, and the Jerry Falwell Library, which yielded 9,102 articles. After applying filtering techniques, the results were narrowed down to 21 articles, which were categorized into "Present Market Conditions," "Flexible Materials for Medical Use," "Applications for Wearable Sensors," and "Potential Use Cases." Discussions were held on prominent materials such as substrate, nanocomposite, and liquid metal materials, exploring their potential applications for chemical and physical sensing, …

Leveraging Automated Fiber Placement Computer Aided Process Planning Framework For Defect Validation And Dynamic Layup Strategies, Joshua Allen Halbritter

Theses and Dissertations

Process planning represents an essential stage of the Automated Fiber Placement (AFP) workflow. It develops useful and efficient machine processes based upon the working material, composite design, and manufacturing resources. The current state of process planning requires a high degree of interaction from the process planner and could greatly benefit from increased automation. Therefore, a list of key steps and functions are created to identify the more difficult and time-consuming phases of process planning. Additionally, a set of metrics must exist by which to evaluate the effectiveness of the manufactured laminate from the machine code created during the Process Planning …

Development Of System Pressure Drop Calculation Methods For Dilute Phase Pneumatic Conveying, Ross Daniel Gorman

Theses and Dissertations

This work is focused on dilute and dense phase pneumatic conveying of bulk solids. The motivation of this work is to use industrial data to scale up existing models for pressure drop in pneumatic conveying systems, determine which models best predict pressure drop in full conveying systems, and find the empirical coefficients that go with these models.

Several major research objectives were accomplished by this work. First, system pressure drop methods were evaluated in this research. Other researchers have focused on single pipe section type pressure drops. Second, the data used in this research both for the machine learning evaluations …

Feasibility Analysis Of A Wave Powered Autonomous Underwater Vehicle, Yingchen Yang, Erick Martinez

Mechanical Engineering Faculty Publications

An autonomous underwater vehicle (AUV) powered by renewable energy would enable it to extend endurance and forward presence with no logistics tail for fuel. A wave powered concept AUV is proposed and analyzed for this purpose. The AUV is in a torpedo shape and employs a fully hull-encapsulated mass-spring-damper system as its power take-off (PTO) unit. While in the recharging mode, the AUV surfaces and converts wave energy for electricity. Considering the AUV of a common size, our analysis indicates that resonance of the AUV and/or its PTO, to be excited by ocean waves, becomes impossible in typical ocean conditions. …

Timing Deterministic Structural Model Updating Considering Impact And Fatigue Damage, Jason Michael Smith Jr.

Theses and Dissertations

Naval ship structures such as support trusses, hull sections, driving machinery, and load-bearing beams are subjected to various damage states that develop on short-term (i.e. impact) and long-term (i.e. fatigue) timescales. Naval structures fitted with a structural health monitoring system with damage detection abilities will enable appropriate real-time adjustments to the ships’ posture and control policies and thus have increased survivability and lethality. A digital twin can provide real-time condition assessment of naval structures when conjoined with a decision-making framework will increase naval ship survivability through informed response management. A fundamental challenge for the development of digital twins is reliable …

Vision Controlled Autonomous Stakebot For Driving Stakes And Its Digital-Twin, Corey Lee Leydig

Theses and Dissertations

In this thesis a novel vision-based AI driven autonomous ‘StakeBot’ is proposed to serve the agricultural 4.0 industries of the future. In recent years supply, demand and production of vegetables that are harvested from plants with weak stems like bell pepper, tomato, eggplant has been significantly up by several fold. With growing demand and new green-house establishments across the country production of vegetables will require a tremendous number of labors which will be hard to supply soon. To overcome the issues in addition to the labor shortages, automation through robotics will be the only viable solution. Plants like bell peppers …