Mechanical Engineering Commons^™

Development & Validation Of A Piv System For Obtaining Data From A Uasb Reactor, Camila D' Bastiani, Gerald Gallagher, David Kennedy, Anthony Reynolds

Conference Papers

Anaerobic digestion processes can generate energy in the form of biogas while treating organic wastewater. The efficiency of the treatment, and thus the generation of biogas, is closely linked to the type and design of the reactor, and the technology used. Granular anaerobic digestion technology offers advantages such as a higher loading rate and reduction of the space needed. However, the hydrodynamics inside this type of reactor can be complex due to the presence of solids (granules) and gas (biogas) phases along with the liquid phase (wastewater). This is one of the reasons why the study and optimization of reactors …

Effects Of Varied Oxygen Levels, Laser Powers, And Scanning Speeds On Manufactured Components By Laser-Based Powder Bed Fusion, Amelia Mcnamee

Honors College Theses

This project addresses the effects of oxygen concentration, laser power, and scanning speed on the melt pool geometry of laser-based powder bed fusion (L-PBF) additively manufactured components. A parametric analysis using the substrate alone was conducted to determine a range of desirable laser powers and scanning speeds. The parameter with the more significant effect will be decided upon based on the depth-to-width ratios (D/W) of the resultant laser weld bead. A range of oxygen levels and scan speeds was selected for the next phase. These samples were then be analyzed for depth-to-width ratios. It was expected that higher oxygen concentrations …

Structural Health Monitoring Of Bioprinted Materials, Kathryn H. Mcintosh

Honors College Theses

Bioprinting is a new method that utilizes additive manufacturing to construct organs, tissues, and other biostructures. This method presents endless possibilities - less reliance on organ donors (according to the Health Resources and Services Administration, 17 people die each day waiting for an organ transplant in the U.S.), more transplant opportunities, and the ability to save significantly more lives. While bioprinting has opened a new frontier in the biomedical field, there may be some research issues that need to be addressed. For example, numerous researchers have focused on creating novel approaches to print complicated geometries. However, the structural integrity or …

Atmospheric Plasma Spraying To Fabricate Metal-Supported Solid Oxide Fuel Cells With Open-Channel Porous Metal Support, Jie Lin, Haixia Li, Wanhua Wang, Peng Qiu, Greg Tao, Kevin Huang, Fanglin Chen

Faculty Publications

Metal-supported solid oxide fuel cells (MS-SOFCs) have been fabricated by applying phase-inversion tape-casting and atmospheric plasma spraying (APS). The effect of the binder amount of the phase-inversion slurries on the microstructure development of the 430L stainless steel metal support was investigated. The pore structures, the viscosity of the slurry, porosity and permeability of the as-prepared metal supports are significantly influenced by the amount of the binder. NiO–scandia-stabilized zirconia (ScSZ) anode, ScSZ electrolyte and La_0.6Sr_0.4Co_0.2Fe0.8O_3−δ (LSCF) cathode layers were consecutively deposited on the metal support with an ideal microstructure by APS process. The effect …

Understanding The Nonlinear Dynamics Governing Vertical-Lift Vehicles With Variable-Speed, Fixed Rotors, Stephanie Vavra, Micah Busboom, Aleea Stanford, Keegan Moore

UNL Student Research Days Posters, Undergraduate

Problem: Traffic significantly limits travel in urban areas. • The NASA Urban Air Mobility Project is developing an air taxi as an alternative mean of transportation (Fig. 1).

Challenge: Operating rotors at different frequencies may cause the cabin to vibrate at high amplitudes. Such effects are currently unknown.

Objective: Understand the effect of variable speed rotors on passenger comfort.

From the reduced-order modeling simulations, it can be assumed that counteracting the rotor speed in-balances can reduce the displacement and vibrations experienced at the center of the wing. In other words, should a rotor not maintain its optimal operation speed, reducing …

Mechanical Behavior Of Materials, Joshua P. Steimel

Pacific Open Texts

This text serves to cover in more detail solid mechanics concepts and specifically the material response to stress and strain. This text spans solid mechanics concepts from stress and strain at an atomistic length scale, to linear elasticity, anisotropy, linear viscoelasticity, plasticity, dislocation generation and interactions, and fracture.

In-Situ Calibrated Digital Process Twin Models For Resource Efficient Manufacturing, David Adeniji, Julius Schoop

Mechanical Engineering Faculty Publications

The chief objective of manufacturing process improvement efforts is to significantly minimize process resources such as time, cost, waste, and consumed energy while improving product quality and process productivity. This paper presents a novel physics-informed optimization approach based on artificial intelligence (AI) to generate digital process twins (DPTs). The utility of the DPT approach is demonstrated in the case of finish machining of aerospace components made from gamma titanium aluminide alloy (γ-TiAl). This particular component has been plagued with persistent quality defects, including surface and sub-surface cracks, which adversely affect resource efficiency. Previous process improvement efforts have been restricted to …

Coconut Oil Space Cooler, Hannah Covington, Alexander Fessler, Largim Zhuta

Mechanical Engineering Senior Theses

During summer months there is reliance on air conditioning (A/C), which is energy intensive in nature. The mass use of A/C units during peak hours taxes the energy grid significantly as a demand spike occurs during these peak hours. This demand spike requires an equal response in supply which disproportionately produces greenhouse gas emissions as reserve power plants come online to meet this demand. These reserve power plants, are relatively inefficient, and more expensive to run than base load plants. The Coconut Oil Space Cooler utilizes the latent thermal storage capabilities of phase change materials (PCMs) to provide a temporary …

A Low-Cost And Low-Tech Solution To Test For Variations Between Multiple Offline Programming Software Packages., Steffen Wendell Bolz

Masters Theses & Specialist Projects

This research paper chronicles the attempt to bring forth a low-cost and low-tech testing methodology whereby multiple offline programming (OLP) software packages’ generated programs may be compared when run on industrial robots. This research was initiated by the discovery that no real research exists to test between iterations of OLP software packages and that most research for positional accuracy and/or repeatability on industrial robots is expensive and technologically intensive. Despite this, many countries’ leaders are pushing for intensive digitalization of manufacturing and Small and Mediumsized Enterprises (SMEs) are noted to be lagging in adoption of such technologies. The research consisted …

Cfd Simulation Of Varying Fuel Jet Placement Of Mach 2 Flow (Paper), Sara Broad

Honors Capstone Projects

Supersonic flow is a concept that has been researched heavily for the past twenty years. It has many applications, with the most notable one being for the defense industry. This project specifically is based off a model that is being currently used for Air Force research. With supersonic flow, where the Mach number is larger than one, there has been continual research specifically on flameholders. Flameholders involve the discussion of the mixing, ignition, and combustion of the fuel that is released into the lower cavity of the scramjet. There is a current standard for the placement of fuel jets, but …

Impulse, Spring 2022, University Marketing And Communications, Jerome J. Lohr College Of Engineering

Impulse (Jerome J. Lohr College of Engineering Publication)

2 | Ahmed Leads Construction and Operations Management
4 | Faculty News
8 | Kelley Steps Aside After 44 Years
12 | Boggs Retires From Mechanical Engineering
14 | Looking At Covid-19 Numbers
16 | Students Help College of Nursing
18 | Midwest Applied Materials Symposium Debuts
20 | Fourth Data Science Event Takes Place
24 | College Achievements
26 | Hard Work Pays Off
28 | Spotlight Shines on Students
30 | Mentoring Program Takes Off
32 | Robotics Club Busy With Activities
34 | The Numbers
36 | Brown, Sieve Honored
38 | Alumna Leads NASA Division
40 …

Intelligent Toolpath Sequence Optimization Approach For Infinite Production Lines, Thanveer Ahammed

Theses

This thesis is concerned with developing a new mathematical model and software for finding the optimal toolpath for an infinite machine production line system. Existing total production time estimation for the Computer Numerical Control (CNC) machining method is solved either on a single machine or in a single operation. The combination of airtime and tool switching time consumes most of the total production time, requiring multiple operations and multiple machine production line systems. A hybrid GA technique along with a modified TSP algorithm was used to find the minimal nonproductive time in these systems. This proposed mathematical model is coded …

Information-Based Particle Flow With Convergence Control, Kari C. Ward, Kyle J. Demars

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A new formulation of the Gaussian particle flow filter is presented using an information theoretic approach. The developed information-based form advances the Gaussian particle flow framework in two ways: it imparts physical meaning to the flow dynamics and provides the ability to easily include modifications for a non-Bayesian update. An orbit determination simulation with high initial uncertainty is used to demonstrate the consistent, robust performance of the information flow filter in situations where the extended Kalman filter fails.

Thermal Simulation Of Additive Manufacturing From G-Code, Noah Foster

Honors Capstones

No abstract provided.

Analytical, Numerical, And Computational Simulation Of The Free Convection Cooling Of An Electronics Enclosure For Assistive Painting Device, Jack Clement

Honors Capstones

No abstract provided.

Dynamic Design And Simulation Of Mechanical Baseball Launcher, Camille Wetekamm

Honors Capstones

No abstract provided.

Measuring Volatile Emissions From Moss Gametophytes: A Review Of Methodologies And New Applications, Danlyn L. Brennan, Leslie M. Kollar, Scott Kiel, Timea Deakova, Aurélie Laguerre, Stuart F. Mcdaniel, Sarah Eppley, Elliott T. Gall, Todd Rosenstiel

Center for Life in Extreme Environments Publications

Mosses inhabit nearly all terrestrial ecosystems and engage in important interactions with nitrogen-fixing microbes, sperm-dispersing arthropods, and other plants. It is hypothesized that these interactions could be mediated by biogenic volatile organic compounds (BVOCs). Moss BVOCs may play fundamental roles in influencing local ecologies, such as biosphere–atmosphere–hydrosphere communications, physiological and evolutionary dynamics, plant–microbe interactions, and gametophyte stress physiology. Further progress in quantifying the composition, magnitude, and variability of moss BVOC emissions, and their response to environmental drivers and metabolic requirements, is limited by methodological and analytical challenges. We review several sampling techniques with various analytical approaches and describe best practices …

Marine Robot Sample Retrieving System, Valeriya Chulyukina, Noah Villar, Kekoa Blair, Mandeep Singh, Nathan Burke

Mechanical Engineering Senior Theses

The exploration of our underwater ecosystems is critical. The aquatic ecosystem has a significant effect on human life, yet our understanding of the oceanic environment is severely lacking. Santa Clara University’s Robotic Systems Lab contributes to subsea exploration through its investment in remotely operated vehicle (ROV) technology. This project was done with the guidance of not only professors in the Robotics Systems Lab, but also stakeholders from the US Geological Survey scientists and researchers from the Monterey Bay Aquarium Research Institute (MBARI). Our team goal was to further advance SCU’s efforts by creating a sediment sample collection system consisting of …

Jet Engine Emissions And Vapor Contrail Reduction Through Increased Combustion Efficiency With The Aim To Mitigate Greenhouse Gases Emissions, Austin J. Brant

Honors College Theses

As society continues to globalize and advance in complexity, the increased demand for business aviation has caused the global travel rate of airlines to increase with each year. With this continual increase in aviation travel, the Federal Aviation Administration (FAA) predicts that the fuel consumption rate is to increase by 1.6 percent as of the year 2025. While this increase in fuel consumption is a positive trait of a thriving aviation community, concerns also arise regarding increased greenhouse gas emissions and enlarged contributions to the greenhouse effect. The most prevalent greenhouse gases associated with jet engine emissions are water vapor, …

Water Based Soil Fluidization Using A Soft Eversion Robot, James E. Hand

Doctoral Dissertations and Master's Theses

Soft robotics, a form of robotics that incorporates nonrigid components, continues to grow in scope, system design, and application. A recent addition to this field is the Vine Robot platform, a bio-inspired robot designed by Stanford University in 2017. Its method of movement, known as eversion, closely resembles the way that a vine grows along a tree, giving it its name. The focus of this research was to take its proven abilities of underwater vine-like movement and soil fluidization, a process where granular materials are converted from a solid-like state to a fluid-like state, to create an underwater eversion robot …

Experimental And Numerical Investigation Of Lauric Acid Melting At Suboptimal Inclines, Casey J. Troxler

Doctoral Dissertations and Master's Theses

Validation experiments are the baseline for completing numerical studies for engineering design. Applications of the enthalpy-porosity model have expanded in research with the growth of new technologies such as metal additive manufacturing or the renewed interest in thermal energy storage for supplementing renewable energy. A simplified experiment examining the melting behavior of lauric acid from an isothermal surface has become a common case for validating the performance of numerical models. Several studies of this rectangular experiment have been repeatedly used as model validation in a variety of problem conditions.

The first part of this study presents experimental data for the …

Effects Of Electrode Negative Pulsing Ratio In Direct Energy Deposition Via Variable-Polarity Cold Metal Transfer Process On The Deposition Behavior And Microstructural Characteristics, Tae Hyun Lee, Cheolhee Kim, Minjung Kang

Mechanical and Materials Engineering Faculty Publications and Presentations

Interest in research on the application of variable-polarity cold metal transfer mode in wire-based direct energy deposition has been growing; particularly popular are investigations into the respective influences of polarity, amplitude of the arc current, and polarity variation sequence on the quality of the final product manufactured via additive manufacturing. The application of the electrode-negative phase is more capable of yielding relatively large droplets and increasing the weight of the deposited material. However, the proportions of the electrode positive phase are typically larger than those of the electrode-negative phase because it maintains arc stability and droplet transfer. This discrepancy has …

The Effect Of Store-To-Store Energy Transfers On The Global Dynamics Of Aircraft, Guilherme Mainieri Eymael, Keegan J. Moore

UNL Student Research Days Posters, Undergraduate

This study analyzes the energy transfer mechanisms when nonlinear devices (stores) are attached to a linear model airplane. For that, a reduced-order model (ROM) was derived to simulate the first two flexible modes of vibration of the primary structure (aircraft) with one store in each wing. Each store can either be locked or unlocked. When locked, it only contributes as mass-effect, and when unlocked, it adds nonlinearity to the system. Simulations were then performed with either both stores locked, one store unlocked, or both stores unlocked. It was found that the attachment of nonlinear stores in the ROM changes the …

A Computer Vision-Based Method For Bolt Loosening Detection, Savannah Burdette

Honors Theses

Routine bolt-loosening inspection plays an essential role in managing and preventing the degradation of our nation’s highway bridges over time. Neglecting to perform these inspections could result in public safety concerns. The study of this thesis develops a cost-effective method of bolt-loosening detection based on computer vision. To this end, two input images of the bolted connections are collected at two different inspection times. The feature points are then identified from the input images, based on which a geometric transformation matrix is applied to correct any perspective differences between the two images. Next, we select the image patches of the …

Secondary Motions Above A Staggered Multi-Scale Rough Wall, Bianca Viggiano, Juliaan Bossuyt, N. Ali, Johan Meyers, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Wind tunnel experiments were performed to investigate turbulent flow over an array of heterogeneous roughness elements using stereoscopic particle image velocimetry. Nine streamwise planes, covering one periodic cell of a multi-scale roughness element that is arranged in a staggered pattern, are combined to quantify mean flow features and Reynolds stresses. Dispersive stresses, arising from spatial variations in the temporally averaged mean velocity, are also presented. The results highlight that the roughness elements create a large deficit pathway along the surfaces. Outer scaling of the time-averaged streamwise velocity presents features which are nearly independent of the roughness element type, with parameters …

A Meshless Approach To Computational Pharmacokinetics, Anthony Matthew Khoury

Doctoral Dissertations and Master's Theses

The meshless method is an incredibly powerful technique for solving a variety of problems with unparalleled accuracy and efficiency. The pharmacokinetic problem of transdermal drug delivery (TDDD) is one such topic and is of significant complexity. The locally collocated meshless method (LCMM) is developed in solution to this topic. First, the meshless method is formulated to model this transport phenomenon and is then validated against an analytical solution of a pharmacokinetic problem set, to demonstrate this accuracy and efficiency. The analytical solution provides a locus by which convergence behavior are evaluated, demonstrating the super convergence of the locally collocated meshless …

Evolution Of High-Frequency Instabilities In The Presence Of Azimuthally Compact Crossflow Vortex Pattern Over A Yawed Cone, Meelan Choudhari, Fei Li, Pedro Paredes, Lian Duan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Hypersonic boundary-layer flows over a circular cone at a moderate yaw angle can support strong crossflow instability away from the windward and leeward rays on the plane of symmetry. Due to the more efficient excitation of stationary crossflow vortices by surface roughness, a possible path to transition in such flows corresponds to rapid amplification of the high-frequency instabilities sustained in the presence of finite amplitude stationary crossflow vortices. This paper presents a computational analysis of crossflow instability over a 7-degree half-angle, yawed circular cone in a Mach 6 free stream. Specifically, the nonlinear evolution of an azimuthally localized crossflow vortex …

Local Prediction Of Laser Powder Bed Fusion Porosity By Short-Wave Infrared Imaging Thermal Feature Porosity Probability Maps, Cody S. Lough, Tao Liu, Xin Wang, Ben Brown, Robert G. Landers, Douglas A. Bristow, James A. Drallmeier, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Local thermal history can significantly vary in parts during metal Additive Manufacturing (AM), leading to local defects. However, the sequential layer-by-layer nature of AM facilitates in-situ part voxelmetric observations that can be used to detect and correct these defects for part qualification and quality control. The challenge is to relate this local radiometric data with local defect information to estimate process error likelihood in future builds. This paper uses a Short-Wave Infrared (SWIR) camera to record the temperature history for parts manufactured with Laser Powder Bed Fusion (LPBF) processes. The porosity from a cylindrical specimen is measured by ex-situ micro-computed …

Marine Robot Sample Retrieving System, Valeriya Chulyukina, Noah Villar, Kekoa Blair, Mandeep Singh, Nathan Burke

Interdisciplinary Design Senior Theses

The exploration of our underwater ecosystems is critical. The aquatic ecosystem has a significant effect on human life, yet our understanding of the oceanic environment is severely lacking. Santa Clara University’s Robotic Systems Lab contributes to subsea exploration through its investment in remotely operated vehicle (ROV) technology. This project was done with the guidance of not only professors in the Robotics Systems Lab, but also stakeholders from the US Geological Survey scientists and researchers from the Monterey Bay Aquarium Research Institute (MBARI). Our team goal was to further advance SCU’s efforts by creating a sediment sample collection system consisting of …

Fundamental Study Of Multiphase Solid/Molten Carbonate Membranes For Co2 Capture And Conversion, Xin Li

Theses and Dissertations

Due to the burning of fossil fuels and human activities, many greenhouse gases such as carbon dioxide are released into the atmosphere, which causes global warming and has a significant negative impact on the human living environment. Therefore, it is imperative to develop carbon capture technologies that can prevent carbon dioxide emission and reduce carbon dioxide concentration in the air. Further, if the captured carbon dioxide can be converted back to fossil fuels, the emission of carbon dioxide is delayed, and more time is gained to develop new and advanced carbon free and clean energy technologies. Motivated by this thought, …