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Full-Text Articles in Mechanical Engineering

Liquid-To-Liquid Low Grade Waste Heat Recovery Using A Two-Channel Loop, Waleed Farwana Dec 2018

Liquid-To-Liquid Low Grade Waste Heat Recovery Using A Two-Channel Loop, Waleed Farwana

Masters Theses

The use of thermoelectric generators (TEGs) for producing electric energy from low grade “waste heat” has been theorized to provide a sustainable and low-cost energy source for electric power plants. The purpose of this study is to model and experimentally validate a TEG device that takes advantage of low grade waste heat (approximately 100-150 degrees Celsius) in liquid form in order to generate power that can be used for various applications in the surrounding environment. This research aims to demonstrate that optimized TEG designs bear the potential to compete with other methods of low grade waste heat energy harvesting in …


Hybrid Processes In Material Removal Of Hard And Brittle Materials, Hossein Mohammadi Dec 2018

Hybrid Processes In Material Removal Of Hard And Brittle Materials, Hossein Mohammadi

Dissertations

New technologies demand new materials with better mechanical, optical, and thermal properties. Materials that are light weight, strong with high resistance to high temperatures, and compatible with a predetermined condition. Such materials usually are challenging to manufacture and process compared to widely available materials such as metals. Ceramics and semiconductors are considered extremely hard and brittle, making them very difficult to cut and manufacture. The other major and fast-growing type of materials are composites (including Ceramic Matrix Composites, CMC) that are also considered very challenging to machine. All these materials have many applications in major industries (i.e. electronics, aerospace, optics, …


Optimization Of Analytical Inverse Heat Transfer Recovery Solution, Nathan Schick Dec 2018

Optimization Of Analytical Inverse Heat Transfer Recovery Solution, Nathan Schick

Masters Theses

This thesis describes the different methods used when trying to solve inverse heat transfer problems, particularly those involving recovering heat flux. There are currently several techniques to measure the temperature history in an object subjected to heat transfer using various temperature sensors, however these types of sensors are gradually being replaced by Temperature Sensitive Paints (TSP), a technique that is more accurate and provides a better spatial resolution. TSP is a polymer that is applied on a base object. Changes in temperature in the polymer result in variations of the luminescence intensity in the paint. These variations can be captured …


Design Of A Portable Biogas Purification And Storage System, Anilkumar Kosna Dec 2018

Design Of A Portable Biogas Purification And Storage System, Anilkumar Kosna

Masters Theses

Biogas is produced from the decomposition of organic materials like manure, sewage sludge or crop fodders in anaerobic digesters. It consists mainly of 40 – 75 % of methane (CH4), 15 – 60 % of carbon dioxide (CO2) and trace amounts of other components. The principle constituents of biogas are similar to natural gas. Natural gas has 87 – 97 % of methane (CH4) and 0.1 – 1 % of carbon dioxide. Natural gas is known to be an alternative fuel with a wide range of applications. The commercial purification technologies exist for large-scale …


Finite Element Modeling And Experimental Characterization Of Knot Configuration Effect On The Mechanical Performance Of Surgical Suture, Arz Y. Qwam Alden Dec 2018

Finite Element Modeling And Experimental Characterization Of Knot Configuration Effect On The Mechanical Performance Of Surgical Suture, Arz Y. Qwam Alden

Dissertations

Tendon injuries in orthopedic surgery and sports medicine are escalating; hence there is great interest in improving tendon repair. The integrity of tendon repair depends in part on a combination of suture material, suture size and knot configuration. Recent studies have indicated the failure of surgical knots as a failure mode during surgical repair. Further, there is still no consensus on the ideal (best/safest) surgical knot techniques. Also, this failure mode is related to stress concentrations, which cannot be easily established with traditional tensile testing. Most researchers have focused on the measurement and comparison of the gross structural response of …


Control-Oriented Automatic Transmission- Based Powertrain Modeling And Simulation With Judder, Harshal B. Kundale Aug 2018

Control-Oriented Automatic Transmission- Based Powertrain Modeling And Simulation With Judder, Harshal B. Kundale

Masters Theses

This work presents automatic transmission-based powertrain modeling. The powertrain consists of an engine, torque converter with lock up clutch, transmission gearbox, propeller shaft, and vehicle body. Simplified powertrain component models are developed for vehicle powertrain dynamic response analysis and future control work. The powertrain components are modeled with algebraic and first order non-linear differential equations. A MATLAB-based powertrain simulation system is developed to investigate the transient characteristics during lock up of torque converter. Simulation results are used in the determination of effects of judder on torque and angular velocity. Clutch judder is a self-excited vibration that occurs during the clutch …


Decomposition And Ionization Of Ionic Liquids, Forrest Grady Kidd Iii Aug 2018

Decomposition And Ionization Of Ionic Liquids, Forrest Grady Kidd Iii

Dissertations

The United States Air Force is interested in developing a situationally responsive space environment. In order to achieve this, dual-mode-propulsion will be utilized. A new class of propellants is being developed for this application based on energetic ionic liquids. Two ionic liquids of current interest are Hydroxylammonium Nitrate (HAN) and Hydroxyethylhydrazinium Nitrate (HEHN) due to their beneficial performance characteristics. The decomposition and ionization chemistry of these two species is investigated in this work. Using GAUSSIAN09 software, reactions with important radicals are explored through quantum chemistry. The energetics of reactions as well as the identity of key product complexes are given. …


Experimental Comparison Between Hollow Cathodes With Cermet, Lanthanum Hexaboride, And Barium Oxide Insert Materials, Nagual Simmons Aug 2018

Experimental Comparison Between Hollow Cathodes With Cermet, Lanthanum Hexaboride, And Barium Oxide Insert Materials, Nagual Simmons

Masters Theses

This thesis compares two different hollow cathode assemblies (HCA) using three different insert materials. NASA’s Jet Propulsion Laboratory (JPL) provided the H6 HCA and the Lanthanum Hexaboride (LaB6) insert. A barium oxide (BaO) insert was purchased from Ebeam and used with the H6 HCA. The novel Cermet material was purchased from Plasma Controls, LLC and the HCA was based on the JPL H6 HCA. Plasma properties in the external region of all three inserts and the internal region of the LaB6 were determine using two separate Langmuir probes. Various operating points were tested at a combination of …


Measurements Of Fluid Structures And Mass Transport In Channel With Fabric Base, Karl David Mcallister Jun 2018

Measurements Of Fluid Structures And Mass Transport In Channel With Fabric Base, Karl David Mcallister

Dissertations

This thesis studies the relationships between flow structures and mass transport (dye concentration) within a Poiseuelle water flow glass chamber using optical flow experimental techniques in turbulent conditions. Through optical flow methods, velocity, vorticity, kinetic energy, Reynolds stress and turbulent production metrics where determined by laser illuminated glass beads and Rhodamine 6G dye removing from three different fabric substrates for multiple horizontal planes and one vertical plane. From the dye intensity, mass concentration metrics were determined providing visualization of velocity and mass transport simultaneously along with kinetic energy, mass flux, and concentration fluctuations.


Design Of Force Versus Displacement Test Stand, Andrew Fritchley Apr 2018

Design Of Force Versus Displacement Test Stand, Andrew Fritchley

Honors Theses

Performing mechanical design around sensors is a critical skill which all engineering students should be familiar with. Of equal importance is gathering and correctly interpreting electrical data from engineering tests. The aim of this project is to design a force versus displacement test stand for applications related to the measurement of spring force-displacement correlation. The design uses a strain gauge load cell, and a magnetic linear encoder to provide accurate, repeatable force and travel measurements. A mechanical design to mount each sensor was created based initial project constraints. Finite element analysis was performed on all critical components to ensure that …


Structural Reinforcement Of Streamline Tubing, Peter Grohs Apr 2018

Structural Reinforcement Of Streamline Tubing, Peter Grohs

Honors Theses

Structural integrity of suspension components is important to the safety and the longevity of vehicles. Streamline tubing, an aerodynamically shaped material used in high performance vehicle controls, can be prone to failure if not properly analyzed for its asymmetric geometry. The component was redesigned as a composite structure using modern materials to make a highly aerodynamic product stiffer, stronger, and lighter per unit weight than a conventional all steel design. Finite element analysis was conducted and five prototypes using different materials were constructed and tested. This method of maximizing component lightness and stiffness using the beneficial properties of each material …


Determination Of Chemical Notch, KChem On Aluminum And Steel When Subjected Under Slow Strain Rate Test In Corrosive Environment, Joshua Teo Lee Kuok Apr 2018

Determination Of Chemical Notch, KChem On Aluminum And Steel When Subjected Under Slow Strain Rate Test In Corrosive Environment, Joshua Teo Lee Kuok

Masters Theses

When designing for any mechanical components or system, the question would arise as to how the material would react to the loads subjected on it? Would the component survive its service load? How would it react to environmental corrosion? To answer these questions, the technique used in this thesis paper is the Slow Strain Rate Test (SSRT) method. Aluminum and steel were chosen as the material to be tested in this paper. Al 7075-T651, and Al 6061-T651 was chosen due to its wide range of application, high strength to weight ratio and ease of machinability. It is highly used in …


Investigation Of Discrete Element Methods For Stud To Turf Interactions, Justin Rittenhouse Apr 2018

Investigation Of Discrete Element Methods For Stud To Turf Interactions, Justin Rittenhouse

Masters Theses

Artificial turf is frequently used in sports today and attempts to advantageously replicate a natural grass/soil playing surface. Despite numerous advantages, the technology is correlated with an increase in injuries. The concept behind this research is to create and validate a discrete element model (DEM) for the ground/foot interaction through the use of open source software. After validation, the goal is to analyze an arrangement of studs to determine what role stud geometry plays on torque [N-mm] and force [N] generation. The validation data was provided through laboratory experiments. Three football studs attached to a rigid bracket were turned at …


Forward-Looking, Velocity-Driven, Powertrain Modeling And Optimal Control For Continuous Variable Transmission, Paresh Deshmukh Apr 2018

Forward-Looking, Velocity-Driven, Powertrain Modeling And Optimal Control For Continuous Variable Transmission, Paresh Deshmukh

Masters Theses

This thesis is the second part of a two-part study focused on improving Continuous Variable Transmission (CVT) ratio management and control. The objective of the overall project was to develop a methodology for a vehicle with a CVT and a downsized gasoline engine to deliver the maximum vehicle fuel economy within drivability and performance constraints. The first part of this study, as described in [1], focuses on developing a cycle driven model for optimizing the CVT ratio. The study presented in this paper focuses on developing a velocity driven model to simulate the real-time behavior of a vehicle. The results …