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Full-Text Articles in Mechanical Engineering
A Modified Peng-Robinson Cubic Equation Of State Based On Bayesian Framework, Wei Chen
A Modified Peng-Robinson Cubic Equation Of State Based On Bayesian Framework, Wei Chen
Theses and Dissertations
Peng-Robinson cubic equations of state (PR-EoSs) as one of the most popular two-parameter cubic equations of state (2P-EoSs) are widely used to calculate thermodynamic properties of pure substances and their mixtures. However, the prediction accuracy of 2P-EoSs varies significantly among different substances due to its intrinsic limitation. To this end, many modifications have focused on changing the dependence structure of 𝛼 function with temperature for PR-EoS to enhance prediction accuracy. In this paper, we propose a Bayesian framework to calibrate a new 𝛼 function, which is a bias-corrected parametrized model form for the PR-EoS. The developed PR-EoS with the calibrated …
A Finite State Automata-Based Description Of Device States For Function Modeling Of Multi-State Technical Devices, Ahmed Mohammed Sobhan Chowdhury
A Finite State Automata-Based Description Of Device States For Function Modeling Of Multi-State Technical Devices, Ahmed Mohammed Sobhan Chowdhury
Theses and Dissertations
Many modern and innovative design problems require multi-modal, reconfigurable solutions. Function modeling (FM) is a common tool used to explore solutions in early stages of mechanical engineering design. Currently, function structure representations do not abet the modeling of formally-defined reconfigurable function models as graph-based function models used in early-stage systems design usually represent only one operational mode of the system. Currently there is a need, but no rigorous formalism to model multiple possible modes in the model and logically predict the behavior of the system as it transitions between the modes. Additionally, function modeling representations will benefit from dynamically capturing …
Development Of Nirs Based Noninvasive Cerebrovascular Regulation Assessment, Stephanie Marie Miller
Development Of Nirs Based Noninvasive Cerebrovascular Regulation Assessment, Stephanie Marie Miller
Theses and Dissertations
Alterations to cerebral blood flow (CBF) have been implicated in diverse neurological conditions, including mild traumatic brain injury, microgravity induced intracranial pressure (ICP) and intraocular pressure (IOP) increases, and mild cognitive impairment. Near infrared spectroscopy (NIRS)-measured regional cerebral tissue oxygen saturation (rSO2) provides an estimate of oxygenation of the interrogated cerebral volume that is useful in identifying trends and changes in oxygen supply to cerebral tissue and has been used to monitor cerebrovascular function during surgery and ventilation. In this study, CO2-inhalation-based hypercapnic breathing challenges were used as a tool to simulate CBF dysregulation, and NIRS was used to monitor …
Optimal Onboard Renewable Energy Charging Method To Improve Micro-Autonomous Underwater Vehicle Deployment Life, Brooklynn Dawn Byford
Optimal Onboard Renewable Energy Charging Method To Improve Micro-Autonomous Underwater Vehicle Deployment Life, Brooklynn Dawn Byford
Theses and Dissertations
This study is an investigation of various methods for recharging a micro autonomous underwater vehicle (μAUV) onboard using renewable energy sources while deployed at sea. The goal of this project is to determine the optimal onboard renewable energy design method to be used to prolong the deployment life of a μAUV. This project specifically targeted vehicles specifications and designs similar to the Riptide Autonomous Solutions’ μAUV[1], which was used for this study. Concluding results are based on the following factors: power generation versus time, structural integrity, and design complexity. The three design method categories investigated are as follows: solar energy, …
Finite Element Method For Assessment Of Air Cushion Skirt Performance, Thomas Arthur Lipscomb
Finite Element Method For Assessment Of Air Cushion Skirt Performance, Thomas Arthur Lipscomb
Theses and Dissertations
The objective of this thesis is to create a method of simulating the performance of new materials for use in air cushion vehicle skirts. These systems currently exhibit unacceptable design lifetimes to be considered for widespread adoption, except in specific applications such a military or rapid transport, where high cost is not an obstacle. This project also focuses on using a new high strain to failure resin system that has recently been developed, in combination with high performance reinforcing fibers, to increase the lifespan of the skirt systems. Using industry-standard finite element modelling (FEM) software, a 3d model of the …
Extreme Response Analysis Of A Site-Specific Offshore Wind Turbine And Offshore Wind Farm Layout Optimization, Xiaosen Xu
Theses and Dissertations
Offshore floating wind turbines have been developed in deep water where bottom-fixed offshore wind turbines are cost-prohibitive. Gulf of Maine has one of the greatest potential wind energy on the east coast. A detailed analysis of metocean data is essential for the dynamic simulation of the floating offshore wind turbine and the offshore wind farm layout optimization. Wave scatter diagram represents the joint probability of significant wave height and peak periods. In the wind energy industry, turbulence intensity is defined as the standard deviation of the horizontal wind speed divided by the average wind speed over certain time period. Uniform …
An Empirical Investigation Of The Dimensions Of Product Similarity Used In Design By Analogy Of Electromechanical Products, Arnold Nkoane Tsoka
An Empirical Investigation Of The Dimensions Of Product Similarity Used In Design By Analogy Of Electromechanical Products, Arnold Nkoane Tsoka
Theses and Dissertations
Analogical reasoning is known to be a core cognitive mechanism behind creative human tasks including the creativity in engineering design. Research shows that during product ideation, designers use analogy to transfer information from prior designs stored in their memory (the source of the analogy) to the task in hand (target of analogy). However, similar to any search process, the source product must be first identified as a potential candidate for analogy before this information transfer can take place. Two products can be similar along multiple dimensions such as their form, function, etc. The dimensions of similarity between two products that …
A Feature-Based Approach To Function Modeling And Reasoning For Thermal-Fluid Systems Engineering, Lakshmi Narasimhon Athinarayana Venkatanarasimhan
A Feature-Based Approach To Function Modeling And Reasoning For Thermal-Fluid Systems Engineering, Lakshmi Narasimhon Athinarayana Venkatanarasimhan
Theses and Dissertations
This research is focused on extending the language of function modeling by developing CAD-like features that are built using primitive functions. These features are reusable units of functions that represent the working principle of a system of higher level of abstraction than the ones of the primitive functions published in prior literature. This approach can be used to also establish an alternate concept/working principle that satisfies the same features, and thus enabling the integration of function models into previously established concept generation programs. It is expected that designers perceive concepts at different levels of abstractions. As a result, the feature-based …
Investigating The Use Of 3d Printing Pens For Additive Manufacturing Component Repair, Kyle Andrew Koren
Investigating The Use Of 3d Printing Pens For Additive Manufacturing Component Repair, Kyle Andrew Koren
Theses and Dissertations
The work presented in this thesis provides fundamental research for investigating the application of 3D printing pens for the repair of components manufactured by 3D printers. Test specimens of three different print orientations were 3D printed with acrylonitrile-butadiene-styrene (ABS) and underwent a tensile load test, through rupture, to determine the maximum tensile load experienced. These ruptured specimens were then manually repaired with a 3D printing pen and put through another tensile test to determine the percentage of maximum tensile load retained. The two print orientations that had the axis of tensile load applied parallel to their print layers experienced rupture …
Alternative Material Selection For Oyster Restoration With An Emphasis On Living Docks, Bridgette Soucy
Alternative Material Selection For Oyster Restoration With An Emphasis On Living Docks, Bridgette Soucy
Theses and Dissertations
Oyster restoration efforts, including Living Shoreline and Living Dock projects, utilize aquaculture-grade plastic oyster mats to mitigate the decline of benthic communities. Aquaculture-grade plastic are known for strength, durability, and resilience to degradation in seawater. Over time, plastics break into microscopic segments commonly referred to as microplastics. Microplastics represent a major concern as marine organisms mistake the small particles for food. Plastics bioaccumulate in marine species, which impacts the marine food web and humans. In order to reduce further negative anthropogenic impacts, natural fibers and nature-inspired concrete mixtures were utilized across a series of experiments in order to determine an …
Nonlinear Attitude Control For A 6u Cubesat With A Flexible, Deployable Boom, Jared Walker
Nonlinear Attitude Control For A 6u Cubesat With A Flexible, Deployable Boom, Jared Walker
Theses and Dissertations
A satellite attitude control system was developed in MathWork’s Simulink for a 6U CubeSat with a flexible appendage payload. The flexible appendage is a boom that is able to store into a compact size and deploy out to 1 meter. The boom deploys a sensor attached to the end of the boom. The boom/sensor payload was modeled as a spring-mass-damper system. The equivalent spring constant of the payload was determined by the the natural frequency of the system. A modal analysis in ANSYS Mechanical was used to determine the natural frequencies and mode shapes of the payload. The attitude control …
Design, Analysis, And Demonstration Of A Multipurpose Fluid Tank Dynamics Characterization Platform, Cameron Ian Hume
Design, Analysis, And Demonstration Of A Multipurpose Fluid Tank Dynamics Characterization Platform, Cameron Ian Hume
Theses and Dissertations
The development of a highly versatile multiphase fluid tank characterization platform is essential to the analysis and improvement of propellant storage tanks. The performance of these tanks is highly critical to the safety and performance of their carriers, especially in the space industry where the propellant makes up the overwhelming majority of the mass of the vehicle. This thesis outlines the design and development of a linear stage used to test and validate the characteristic of multiphase fluids inside moving specific tanks. This document will walk through the steps taken to bring a new linear stage to life, from the …
Examining The Impact Of Student Motivation On Performance In Mechanical Engineering Design Courses, Elisabeth Kames
Examining The Impact Of Student Motivation On Performance In Mechanical Engineering Design Courses, Elisabeth Kames
Theses and Dissertations
Design courses are an integral component of undergraduate engineering education. Design is recognized as one of the primary responsibilities of an engineer in industry. New designs are responsible for stimulating sales and company growth.1 This dissertation outlines a study seeking to explore the impact of student motivation factors on course performance of mechanical engineering students in design courses. The first design course, cornerstone design, takes place during the first semester of freshman year. The second course, capstone design, takes place during the student’s final year of undergraduate study. An adapted version of the Motivated Strategies for Learning Questionnaire (MSLQ) is …
Thermal Management Design Of A 6u Cubesat With A High-Power Additive Manufacturing Payload Using Analytical Modeling With Experimental Validation, Todd Wayne Fennell Jr.
Thermal Management Design Of A 6u Cubesat With A High-Power Additive Manufacturing Payload Using Analytical Modeling With Experimental Validation, Todd Wayne Fennell Jr.
Theses and Dissertations
As the capacity of compact battery technology for spacecraft missions continue to improve, small payloads are less constrained by power limitations, thus relatively high-power applications may be considered. AddCube is a mission to develop a platform, conforming to the 6U CubeSat Standard capable of demonstrating on-orbit Additive Manufacturing technology. A critical concern is the development and demonstration of a thermal management design that is capable of handling the significant waste heat generated by the high-power Additive Manufacturing payload while maintaining component temperatures throughout the spacecraft within an acceptable range. This effort includes a trade study for the evaluation of candidate …
Analysis Of Polyester Interleafs For Toughness Enhancement In Composite Structures, Adnan Gheryani
Analysis Of Polyester Interleafs For Toughness Enhancement In Composite Structures, Adnan Gheryani
Theses and Dissertations
Delamination between composite layers is one of primary weaknesses in composite material structure. Various researchers have developed techniques to control delamination in laminated structures. One of these techniques is “interleaving,” adding high toughness material to key interfaces in a laminate. This research studies using polyester veil as a low-cost interleaf alternative to other materials and focuses on a non-woven, polyester spunbond material. Two different interleaf thicknesses, 0.18 mm and 0.74 mm are primarily used. In addition, fine 4 g/m2 polyester was also compared. Carbon/epoxy composites are manufactured using 2x2 Twill 24”-12k carbon fibers embedded in an epoxy resin, with polyester …
A Study On Reaction Rate Factors Of A Single-Step Combustion Mechanism For Gasoline Hcci Combustion, Pakawat Panuwatsuk
A Study On Reaction Rate Factors Of A Single-Step Combustion Mechanism For Gasoline Hcci Combustion, Pakawat Panuwatsuk
Theses and Dissertations
Homogeneous Charge Compression Ignition (HCCI) engine has been invented to achieve the advantages of both diesel and gasoline engines. HCCI engine can run with a higher compression ratio like diesel engine in order to achieve high thermal efficiency. Meanwhile, like gasoline engine, the engine produces less NOx gas and particulate matters than diesel engine. However, there are several difficulties associated with HCCI combustion, which still require further development to the engine. The most important issues are autoignition timing and narrow operational range. In order to develop an HCCI engine, a numerical simulation can significantly save cost, time and resources over …
Living Docks: Structural Implications And Determination Of Force Coefficients Of Oyster Mats On Dock Pilings In The Indian River Lagoon, Ryan Christiansen
Living Docks: Structural Implications And Determination Of Force Coefficients Of Oyster Mats On Dock Pilings In The Indian River Lagoon, Ryan Christiansen
Theses and Dissertations
Brevard County, Florida, is facing rapid population growth and increased pollution entering the Indian River Lagoon (IRL), impairing water quality and damaging the ecosystem. This is problematic not only for public health and environmental stability, but also for the economy. The Living Docks initiative was created to combat environmental degrade in the lagoon and restore natural functions back to the ecosystem. With increased urbanization along coastal systems, there is opportunity for new forms of ecological engineering such as Living Docks, which attaches oyster mats to dock pilings as a means to promote the growth of filter feeding organisms. It is …
Design Of An Environmentally Responsive Grooming Tool To Aid In Underwater Navigation, Bruce Huntress Walker Iii
Design Of An Environmentally Responsive Grooming Tool To Aid In Underwater Navigation, Bruce Huntress Walker Iii
Theses and Dissertations
Underwater hull grooming is a proactive approach to ship hull husbandry. It has been defined as the frequent and gentle wiping of a ship hull coating to maintain it free of fouling. One of the challenges to implementing a grooming schedule is the control and navigation of the devices over the surface of the hull. This thesis presents prior research that has developed self-attaching rotating brushes as an effective method to groom fouling control coatings and the results from several years of implementation in the marine environment. The hypothesis of this thesis is that the condition of the ship hull …