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Articles 571 - 600 of 3234
Full-Text Articles in Mechanical Engineering
Classification Of Electrical Current Used In Electroplastic Forming, Tyler Grimm
Classification Of Electrical Current Used In Electroplastic Forming, Tyler Grimm
All Dissertations
Electrically assisted manufacturing (EAM) is the direct application of an electric current to a workpiece during manufacturing. This advanced manufacturing process has been shown to produce anomalous effects which extend beyond the current state of modeling of thermal influences. These purported non-thermal effects have collectively been termed electroplastic effects (EPEs).
While there is a distinct difference in results between steady-state (ideal DC) testing and pulsed current testing, the very definition of these two EAM methods has not been well established. A "long" pulse may be considered DC current; a "short" pulse may produce electroplastic effects; and even "steady-state" current shapes …
Aerodynamic Implications Of A Bio‐Inspired Rotating Empennage Design For Control Of A Fighter Aircraft, Christian R. Bolander
Aerodynamic Implications Of A Bio‐Inspired Rotating Empennage Design For Control Of A Fighter Aircraft, Christian R. Bolander
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
This dissertation presents an analysis of the aerodynamics for an aircraft using a novel, bio-inspired control system. The control system is a rotating tail, that is inspired by the way in which birds use their tail to control their flight. An aerodynamic model for a baseline aircraft and a bio-inspired variant are created by referencing well-known relationships for the aerodynamics of flight, which are then used to analyze the available flight envelope at which each aircraft can reach two different equilibrium states. An analysis of the total aerodynamic control authority of each aircraft is also included along with a preliminary …
Servo Mounting Device And Collective Control System Design For The Forward Flight Aero Test Stand, Aaron Jones
Servo Mounting Device And Collective Control System Design For The Forward Flight Aero Test Stand, Aaron Jones
NASA-Missouri Space Grant Consortium
The majority of the ten-week internship was spent designing a servo mounting device, and a collective control system for the Forward Flight Aero Test (FFAT) stand. The servo mounting device uses four threaded standoffs along with a top plate, held together with screws, that raises the servos above the protruding threaded rods and screws. The collective control system is a rectangular block that attaches the swashplate to the servo arms connected to the servo motor. This control rod is used to translate the rotation from the servo arm into collective control for the blade angle. The control rod has two …
An Introductory Investigation Of Dust Devils On Mars: Computational Fluid Dynamics Modeling, Alexios Nicolas Philippou, Kakkattukuzhy M. Issac
An Introductory Investigation Of Dust Devils On Mars: Computational Fluid Dynamics Modeling, Alexios Nicolas Philippou, Kakkattukuzhy M. Issac
NASA-Missouri Space Grant Consortium
This report investigates the flow characteristics of tornado like vortices which can be used to describe an array of axisymmetric rotating vertical columns of fluid such as dust devils, steam devils and tornadoes. These vortices have been recreated within vortex chambers in research facilities, but in focus of this report the investigation is conducted through numerical simulations using the Computational Fluid Dynamics (CFD) software package provided by ANSYS. By varying the main governing nondimensional parameter of swirl ratio through the computational domain’s boundary conditions, different flow characteristics appear which confirm theories presented in previous papers. This enables the research conducted …
Modeling And Simulation Of An Electrostatic Lunar Particle Sieve, Aaron Berkhoff
Modeling And Simulation Of An Electrostatic Lunar Particle Sieve, Aaron Berkhoff
NASA-Missouri Space Grant Consortium
The following research was conducted to develop a kinetic particle model, which simulates an electromagnetic sieve used for in-situ material utilization on the lunar surface. A code package was developed to simulate an electromagnetic sieve that uses electrodes to transport fine particles within a cylindrical device. Specifically, this research generates an initial working model for the sieve and tests different electrode configurations. The simulation models different electric fields generated by electrodes, kinetic particle dynamics, and lunar particle distribution. During the case study, which investigates different electrode configurations, it was determined that electrodes oriented such that electrodes located above and below …
Nationwide Eclipse Ballooning Project: April 2023 Status Report, Jill Schmidt
Nationwide Eclipse Ballooning Project: April 2023 Status Report, Jill Schmidt
NASA-Missouri Space Grant Consortium
This report details the progress of the Missouri S&T Nationwide Eclipse Ballooning Project as of April 2023 and the future work the team will complete throughout the remainder of 2023 and 2024. This project began in January 2023, and students have been completing preliminary training activities, so they are prepared to begin assembling and testing the eclipse payloads during summer 2023. Throughout the summer, all team members will be actively engaged in this research project and participating in outreach events related to high altitude ballooning.
High Pressure Injection Process For Ceramic Composites, Samuel Weiler
High Pressure Injection Process For Ceramic Composites, Samuel Weiler
NASA-Missouri Space Grant Consortium
Ceramic materials are valued for good heat resistance and corrosion resistance. Due to these benefits, they are widely used in the aviation, automotive, medical, construction, and other industries. Ceramic materials are also both hard and brittle, qualities that are not ideal in many applications. To reduce brittleness, and other undesirable characteristics of ceramics, engineers have turned to composites to increase the mechanical properties of these materials. By adding composite particles or fibers, these characteristics can be improved. Constructing ceramic composites is not without its challenges, however. Current processes are prone to high porosity, high shrinkage, and poor accuracy of parts. …
Performance Evaluation Of Additively Manufactured Carbon/Peek Composites, Matik S. Heskin
Performance Evaluation Of Additively Manufactured Carbon/Peek Composites, Matik S. Heskin
NASA-Missouri Space Grant Consortium
Carbon/PEEK composites have a broad range of applications due to their combinations of superior creep properties and excellent strength to weight ratios. Like all fiber-based composites they are limited geometrically by their required manufacturing processes. Additively manufactured (AM) materials overcome this issue and can be formed into incredibly complex shapes. By combining these two fields, a material limited in application by geometry can have its shortcomings supported with AM processes.
AM carbon/PEEK composites have already been created but this relatively new material still needs property characterization. Therefore, the objective of this work will be to evaluate the structural performance of …
From Land Grant To Space Grant, Mohammad Dehghani
From Land Grant To Space Grant, Mohammad Dehghani
NASA-Missouri Space Grant Consortium
No abstract provided.
Comparison Of Injection Molded Abs Using Conventional Steel And Novel Composite-Based Additively Manufactured Mold Plates, John Mitchell
Comparison Of Injection Molded Abs Using Conventional Steel And Novel Composite-Based Additively Manufactured Mold Plates, John Mitchell
NASA-Missouri Space Grant Consortium
Polymer injection molding processes have been used for over 100 years to create high-volume parts quickly and efficiently. Injection molding uses mold plates that are traditionally made of very hard tool steels, such as P20 steel, which is extremely heavy and has very long lead times to build new molds. In this study, composite-based additive manufacturing (CBAM) was used to create mold plates using long-fiber carbon fiber and polyether ether ketone (PEEK). These mold plates were installed in an injection molding machine, and rectangular flat plates were produced using Lustran 348 acrylonitrile butadiene styrene (ABS). Tensile testing was performed on …
Multi-Disciplinary Analysis Surrogate Based On Twin-Generator Generative Adversarial Networks For Electric Drone, Samuel Sisk
Multi-Disciplinary Analysis Surrogate Based On Twin-Generator Generative Adversarial Networks For Electric Drone, Samuel Sisk
NASA-Missouri Space Grant Consortium
Multi-Disciplinary Analysis and Optimization (MDAO) plays an important role in the future of aviation, especially relating to Urban Air Mobility (UAM). MDAO for UAM effectively quantifies and maximizes system performance and safety while minimizing cost or consumption. Electric drone takeoff trajectory design aims to minimize energy consumption while fulfilling acceleration and other constraints to keep passengers comfortable. Conventional simulation-based MDAO is computationally expensive due to repeatedly evaluating physics-based models while naïvely constructing machine learning predictive models, also known as surrogate models, do not scale well with large-scale problems due to the “curse of dimensionality”. A twin-generator generative adversarial networks (Twin-GAN) …
Progress In Optimization Of Electrostatic Sieve Concept For Transport Of Lunar Regolith Using A Genetic Algorithm, Easton Ingram
Progress In Optimization Of Electrostatic Sieve Concept For Transport Of Lunar Regolith Using A Genetic Algorithm, Easton Ingram
NASA-Missouri Space Grant Consortium
A method for optimizing electrostatic dust transport systems using a genetic algorithm is in development. Applications to electrostatic sieving are discussed for use on the lunar surface. This simulation will allow for rapid development, testing, and optimization of electrostatic particle transport designs with large search spaces. Current progress and ongoing work for the simulation is reviewed.
Lunar In-Situ Aluminum Production Through Molten Salt Electrolysis (Lisap-Mse), Jacob Ortega, Jeffrey D. Smith, Fateme Rezaei, David Bayless, William P. Schonberg, Daniel S. Stutts, Daoru Frank Han
Lunar In-Situ Aluminum Production Through Molten Salt Electrolysis (Lisap-Mse), Jacob Ortega, Jeffrey D. Smith, Fateme Rezaei, David Bayless, William P. Schonberg, Daniel S. Stutts, Daoru Frank Han
NASA-Missouri Space Grant Consortium
The goal of Artemis is to establish a sustained presence on the Moon. To achieve so, numerous resources are necessary. The Moon contains several essential elements needed to sustain human presence. Most of those elements are trapped in the form of minerals. To refine those minerals into useful materials, reduction methods are needed. Most reduction methods on Earth require large amounts of mass and power which is unrealistic for early stages of building a lunar base. To solve this problem, we are developing a concept of Lunar In-Situ Aluminum Production through Molten Salt Electrolysis (LISAP-MSE).
The LISAP-MSE project, if successful, …
Supersonic Wind Tunnel Improvement For Advanced Laser-Based Non-Intrusive Diagnostics, Joshua Gary
Supersonic Wind Tunnel Improvement For Advanced Laser-Based Non-Intrusive Diagnostics, Joshua Gary
NASA-Missouri Space Grant Consortium
This work presents an approach to the design, and theoretical application, of a new test section for the Missouri S&T Supersonic Wind Tunnel to be used with advanced laserbased non-intrusive diagnostics. Supersonic wind tunnel test sections present multiple challenges. They need to ensure proper flow by avoiding jet-flow interactions and ensuring started conditions; they need to withstand large pressure loads in the case of tunnel unstart; they need to provide easy optical access for advanced diagnostics; they need to be modular and adaptable for different experiments. This work presents detailed analytical and numerical analyses of the mechanical loads. Based on …
Effects Of Tempering Temperature On Gas Turbine Fan Cases, Seth Utter
Effects Of Tempering Temperature On Gas Turbine Fan Cases, Seth Utter
Honors Scholar Theses
The project aimed to investigate the effects of tempering temperature on metals used for gas turbine engine fan cases as a major relevant concern is containing blades in during blade-out events. There are three ways to accomplish this: using a thicker metal, incorporating different materials into the case, or heat treating the metal. This project focused on the third solution: reviewing the impact toughness and hardness of fractured samples and their equivalent ductile-to-brittle transition shear faces. Given its availability, 1045 steel, as opposed to aerospace grade metals, was used for in-house testing. The data obtained from these experiments were then …
Experimental And Numerical Studies Of Slurry-Based Coextrusion Deposition Of Continuous Carbon Fiber Micro-Batteries To Additively Manufacture 3d Structural Battery Composites, Aditya R. Thakur, Xiangyang Dong
Experimental And Numerical Studies Of Slurry-Based Coextrusion Deposition Of Continuous Carbon Fiber Micro-Batteries To Additively Manufacture 3d Structural Battery Composites, Aditya R. Thakur, Xiangyang Dong
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Carbon Fiber Structural Battery Composites Have Recently Attracted Growing Interests Due to their Potentials of Simultaneously Carrying Mechanical Loads and Storing Electrical Energy for Lightweight Application. in This Study, We Present a Slurry-Based Coextrusion Deposition Method to Additively Manufacture 3D Structural Battery Composites from Carbon Fiber Micro-Batteries. Cathode Slurry is Coextruded Together with Solid Polymer Electrolyte-Coated Carbon Fibers in a Single Deposition. a Network of Carbon Fiber Micro-Batteries is Achieved within the Fabricated Structural Battery Composites. Electrochemical Tests Show a Stable Charge-Discharge Performance Up to 100 Cycles. the Rheological Behavior of the Cathode Slurry is Found to Govern the Coextrusion …
Energy Storage Can Increase The Value And Flexibility Of A Nuclear Power Plant But Makes Plant Economics More Subject To Uncertainty In Electricity Price, Jacob Bryan
Student Research Symposium
Regional electricity markets currently rely heavily on coal and natural gas resources to meet electricity demand. Intermittent renewable resources like wind and solar power are location-dependent and are not dispatchable resources. Flexible nuclear power, achieved through the use of integrated thermal energy storage, may be able to complement these renewable resources to provide clean, predictable power in an evolving electricity grid. This study considers such a flexible nuclear plant and seeks to address a fundamental modeling question: which uncertain model inputs have a significant effect on the economics of the system, and to what degree? These questions are addressed by …
Heat Transfer Analysis Of Microchannels Heat Sink With Sidewall Fins, Ahmad Ala Eddin Rahhal
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
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 …
Rocketing Ahead: Basketball Player Plans To Apply Mechanical Engineering To Aerospace, Rocky Garza Jr.
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 …
Development Of Mirror Flexures For Use In The Muvi Instrument, Colin W. Harrop
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 …
Advanced Ensemble Modeling Method For Space Object State Prediction Accounting For Uncertainty In Atmospheric Density, Smriti Nandan Paul, Richard J. Licata, Piyush M. Mehta
Advanced Ensemble Modeling Method For Space Object State Prediction Accounting For Uncertainty In Atmospheric Density, Smriti Nandan Paul, Richard J. Licata, Piyush M. Mehta
Mechanical and Aerospace Engineering Faculty Research & Creative Works
For objects in the low Earth orbit region, uncertainty in atmospheric density estimation is an important source of orbit prediction error, which is critical for space traffic management activities such as the satellite conjunction analysis. This paper investigates the evolution of orbit error distribution in the presence of atmospheric density uncertainties, which are modeled using probabilistic machine learning techniques. The recently proposed "HASDM-ML," "CHAMP-ML," and "MSIS-UQ" machine learning models for density estimation (Licata and Mehta, 2022b; Licata et al., 2022b) are used in this work. The investigation is convoluted because of the spatial and temporal correlation of the atmospheric density …
Microscale Modelling Of Lightning Damage In Fibre-Reinforced Composites, Scott L. J. Millen, Juhyeong Lee
Microscale Modelling Of Lightning Damage In Fibre-Reinforced Composites, Scott L. J. Millen, Juhyeong Lee
Mechanical and Aerospace Engineering Faculty Publications
In this work, three-dimensional (3D) finite element simulations were undertaken to study the effects of lightning strikes on the microscale behaviour of continuous fibre-reinforced composite materials and to predict and understand complex lightning damage mechanisms. This approach is different from the conventional mesoscale or macroscale level of analysis, that predicts the overall lightning damage in composite laminates, thus providing better understanding of lightning-induced thermo-mechanical damage at a fundamental level. Micromechanical representative volume element (RVE) models of a UD composite laminate were created with circular carbon fibres randomly distributed in an epoxy matrix. The effects of various grounding conditions (one-, two-, …
Smart Wifi Thermostat-Enabled Thermal Comfort Control In Residences, Robert Lou, Kevin P. Hallinan, Kefan Huang, Timothy Reissman
Smart Wifi Thermostat-Enabled Thermal Comfort Control In Residences, Robert Lou, Kevin P. Hallinan, Kefan Huang, Timothy Reissman
Mechanical and Aerospace Engineering Faculty Publications
The present research leverages prior works to automatically estimate wall and ceiling R-values using a combination of a smart WiFi thermostat, building geometry, and historical energy consumption data to improve the calculation of the mean radiant temperature (MRT), which is integral to the determination of thermal comfort in buildings. To assess the potential of this approach for realizing energy savings in any residence, machine learning predictive models of indoor temperature and humidity, based upon a nonlinear autoregressive exogenous model (NARX), were developed. The developed models were used to calculate the temperature and humidity set-points needed to achieve minimum thermal comfort …
Shock Induced Trailing Edge Separation Effect On F-16 Limit-Cycle Oscillation, Eric D. Stubblefield
Shock Induced Trailing Edge Separation Effect On F-16 Limit-Cycle Oscillation, Eric D. Stubblefield
Theses and Dissertations
No abstract provided.
Decomposition Of The Skin-Friction Coefficient Of Compressible Boundary Layers, Dongdong Xu, Pierre Ricco, Lian Duan
Decomposition Of The Skin-Friction Coefficient Of Compressible Boundary Layers, Dongdong Xu, Pierre Ricco, Lian Duan
Mechanical and Aerospace Engineering Faculty Research & Creative Works
We derive an integral formula for the skin-friction coefficient of compressible boundary layers by extending the formula of Elnahhas and Johnson ["On the enhancement of boundary layer skin friction by turbulence: An angular momentum approach, "J. Fluid Mech. 940, A36 (2022)] for incompressible boundary layers. The skin-friction coefficient is decomposed into the sum of the contributions of the laminar coefficient, the change of the dynamic viscosity with the temperature, the Favre-Reynolds stresses, and the mean flow. This decomposition is applied to numerical data for laminar and turbulent boundary layers, and the role of each term on the wall-shear stress is …
Detonation Confinement In A Second-Generation Radial Rotating Engine, John T. Ursino
Detonation Confinement In A Second-Generation Radial Rotating Engine, John T. Ursino
Theses and Dissertations
In recent years, Rotating Detonation Engines (RDEs) have been coupled with turbomachinery to harness the benefits of detonative combustion. A novel type of RDE, referred to as the disk or Radial RDE (RRDE), has been developed in pursuit of length and weight savings compared to a traditional annular flow RDE. This design includes a disk-shaped device within which reactants flow from the outer radius, detonate, and exit the inner radius. In this paper several modifications have been made to a previously tested RRDE to address issues that arose with the original design. The combustion chamber diameter has been increased to …
Development Of Novel Turbomachinery Manufacturing Methods, Timothy P. Winkler
Development Of Novel Turbomachinery Manufacturing Methods, Timothy P. Winkler
Theses and Dissertations
Compact turbine engines are of increasing interest as a means of propulsion for small, lightweight, low cost, unmanned aerial systems. This study looks to leverage advancements in novel manufacturing technology to produce turbomachinery components while simultaneously reducing costs and manufacturing time. To determine the feasibility of drop-in replacements for stock components this study focused on several research areas. This included materials research on both polymer-reinforced and ceramic materials, specimen tensile testing to determine temperature-dependent material properties, finite element analysis of multiple candidate materials, design and fabrication of a spin test rig, and physical spin testing of manufactured components to predict …
Hemodynamic Investigations In Intracranial Aneurysms: A Commentary, Hang Yi, Mark Johnson, Luke Bramlage, Zifeng Yang, Bryan Ludwig
Hemodynamic Investigations In Intracranial Aneurysms: A Commentary, Hang Yi, Mark Johnson, Luke Bramlage, Zifeng Yang, Bryan Ludwig
Mechanical and Materials Engineering Faculty Publications
Intracranial aneurysms (IAs) are abnormal bulges in a blood vessel in the brain that have a potential to rupture and even causing a stroke, which can lead to lasting brain damage, long-term disability, or even loss of life. It has been widely acknowledged that hemodynamic factors, e.g., instantaneous wall shear stress, time-averaged wall shear stress, wall shear stress gradient, gradient oscillatory number, oscillatory shear index, pulsatile blood flow waveform (flow rate magnitude and shape, physical flow period), relative residence time/turnover time, blood pressure, and vortex (i.e., size, location, and numbers), have a close relationship with the pathobiology (i.e., initiation, growth, …
Simulation Of Natural Tornado Genesis And Evolution From An Initial Instability Profile, Kakkattukuzhy M. Issac
Simulation Of Natural Tornado Genesis And Evolution From An Initial Instability Profile, Kakkattukuzhy M. Issac
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A likely mechanism for the little-understood tornado genesis is proposed and its numerical implementation is presented. The Burgers-Rott vortex with its axis in the vertical direction is introduced as an instability mechanism, and the flow field then evolves under the influence of the atmospheric pressure, temperature and density variations with altitude. Buoyancy effects are implemented using the Boussinesq model. Results are presented and discussed for a set of conditions including mesh type and size, different turbulence models, and a few different boundary conditions. Post-processed results of the transient simulations including animations contain a wealth of information to help analyze tornado …