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2021

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Articles 931 - 960 of 1560

Full-Text Articles in Mechanical Engineering

Identification Of Active Surface Species In Molten Carbonates Using In Situ Raman Spectroscopy, Peng Zhang, Tao Wu, Kevin Huang Apr 2021

Identification Of Active Surface Species In Molten Carbonates Using In Situ Raman Spectroscopy, Peng Zhang, Tao Wu, Kevin Huang

Faculty Publications

Here we report the results of a study on active surface species of a pristine and modified (Li-Na)2CO3 eutectic using in situ Raman spectroscopy technique. The effects of gas compositions, temperature, time, and alkaline earth have been systematically studied. The species of CO42–, HCO4, and C2O52– are identified as the three major active species on the surface of (Li-Na)2CO3 eutectic by a combined Raman spectroscopy and theoretical density functional theory calculations. The results further reveal that CO42–, HCO4, …


Fundamental Dislocation Solutions For Infinite And Semi-Infinite Media, Luo Li Mr Apr 2021

Fundamental Dislocation Solutions For Infinite And Semi-Infinite Media, Luo Li Mr

Mechanical Engineering ETDs

Much research has gone into determining stress fields of dislocation, as the understanding of dislocations is fundamental to understanding metal or crystal plasticity. In this thesis, the stress field of a rectangular dislocation loop in an infinite isotropic solid is developed for a Volterra-type dislocation with three non-zero Burgers vector components. Also, the stress and strain fields of a rectangular dislocation loop in an isotropic solid, which is a semi-infinite medium, are obtained here for a Volterra-type dislocation. Moreover, analytical and numerical verifications of the developed stress/strain fields are performed. This is done by ensuring the satisfaction of the equilibrium …


Autonomous Shock Sensing Using Bi-Stable Triboelectric Generators And Mems Electrostatic Levitation Actuators, Mohammad Mousavi, Mohammad Alzgool, Shahrzad Towfighian Apr 2021

Autonomous Shock Sensing Using Bi-Stable Triboelectric Generators And Mems Electrostatic Levitation Actuators, Mohammad Mousavi, Mohammad Alzgool, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

This work presents an automatic threshold shock-sensing trigger system that consists of a bi-stable triboelectric transducer and a levitation-based electrostatic mechanism. The bi-stable mechanism is sensitive to mechanical shocks and releases impact energy when the shock is strong enough. A triboelectric generator produces voltage when it receives a mechanical shock. The voltage is proportional to the mechanical shock. When the voltage exceed a certain level, the initially pulled-in Microelectromechanical system (MEMS) switch is opened and can disconnect the current in a safety electronic system. The MEMS switch combines two mechanisms of gap-closing (parallel-plate electrodes) with electrostatic levitation (side electrodes) to …


Solid–Liquid Interface Temperature Measurement Of Evaporating Droplet Using Thermoresponsive Polymer Aqueous Solution, Hyung Ju Lee, Chan Ho Jeong, Dae Yun Kim, Chang Kyoung Choi, Seong Hyuk Lee Apr 2021

Solid–Liquid Interface Temperature Measurement Of Evaporating Droplet Using Thermoresponsive Polymer Aqueous Solution, Hyung Ju Lee, Chan Ho Jeong, Dae Yun Kim, Chang Kyoung Choi, Seong Hyuk Lee

Michigan Tech Publications, Part 1

The present study aims to measure the solid–liquid interface temperature of an evaporating droplet on a heated surface using a thermoresponsive polymer. Poly(N-isopropylacrylamide) (pNIPAM) was used owing to its sensitive optical and mechanical properties to the temperature. We also measured the refractive index variation of the pNIPAM solution by using the surface plasmon resonance imaging (SPRi). In particular, the present study proposed a new method to measure the solid–liquid interface temperature using the correlation among reflectance, refractive index, and temperature. It was found that the reflectance of a pNIPAM solution decreased after the droplet deposition. The solid–liquid interface temperature, estimated …


Investigation Of Dusting Hole Film Cooling On A Transonic Turbine Blade Tip With A Squealer, Matthew Cox Apr 2021

Investigation Of Dusting Hole Film Cooling On A Transonic Turbine Blade Tip With A Squealer, Matthew Cox

Honors Capstone Projects and Theses

No abstract provided.


Effects On Fatigue Of Applying Titanium Nitride Coating To 17-4 Ph Stainless Steel, Jade Welsh, Scott Zinn, Steve Stagon, Jutima Simsiriwong Apr 2021

Effects On Fatigue Of Applying Titanium Nitride Coating To 17-4 Ph Stainless Steel, Jade Welsh, Scott Zinn, Steve Stagon, Jutima Simsiriwong

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Honorable Mention Winner

Surface coatings when applied to metals have many useful applications such as improving the biocompatibility and resistance to corrosion and wear. In this study, the effect of thickness of titanium nitride (TiN) on 17-4 precipitation hardened (PH) stainless steel under cyclic (i.e. fatigue) loading is investigated. TiN are applied to wrought 17-4 PH stainless steel using physical vapor deposition (PVD) technique in a low-pressure vacuum chamber filled with a mixture of inert argon and nitrogen gases with a ratio of 10:1. In addition, these specimens are subjected to two different vapor durations, but a constant voltage and …


Open Source 3d-Printable Planetary Roller Screw For Food Processing Applications, Marcello C. Guadagno, Jacob M. Loss, Joshua M. Pearce Apr 2021

Open Source 3d-Printable Planetary Roller Screw For Food Processing Applications, Marcello C. Guadagno, Jacob M. Loss, Joshua M. Pearce

Michigan Tech Publications, Part 1

Historically, open source agriculture (OSA) was based on grassroots technology generally manufactured by hand tools or with manual machining. The rise of distributed digital manufacturing provides an opportunity for much more rapid lateral scaling of open source appropriate technologies for agriculture. However, the most mature distributed manufacturing area is plastic, which has limited use for many OSA applications. To overcome this limitation with design, this study reports on of a completely 3D-printable planetary roller screw linear actuator. The device is designed as a parametric script-based computer aided design (CAD) package to allow for the easy adaption for a number of …


Numerical Modeling Of The Fiber Deposition Flow In Extrusion-Based 3d Bioprinting, Dhanvanth Jaya Talluri Apr 2021

Numerical Modeling Of The Fiber Deposition Flow In Extrusion-Based 3d Bioprinting, Dhanvanth Jaya Talluri

Theses and Dissertations

Extrusion bioprinting involves the deposition of bioinks in a layer-wise fashion to build 3D structures that mimic natural living systems' behavior in tissue engineering. Hydrogels are the most common bioinks, in which their viscosity properties are dependent on the shear-rate, such as Non-Newtonian fluids. Numerical simulation of extrusion bioprinting may help study the flow properties of hydrogels and designing improved bioinks. In this thesis, the instability caused by the shear-thinning or -thickening parameter during extrusion is numerically compared with the theoretical estimations. The process of fiber deposition of hydrogels onto a substrate through the single and coaxial nozzle is done …


Analysis Of Data To Evaluate The Performance Of Air Filters Used For Filtering Nanoscale Particles Generated By Smoke, Pascal J. Wagemaker Apr 2021

Analysis Of Data To Evaluate The Performance Of Air Filters Used For Filtering Nanoscale Particles Generated By Smoke, Pascal J. Wagemaker

Honors College Theses

The main goal of this research project is to determine the effectiveness of commercially available air filters and to compare different kinds of commercially available air filters in certain categories. With recent record-breaking wildfires and the Covid-19 pandemic, research on the effects and features of nanoparticles has become increasingly important. Inhalation of nanoparticles in smoke can result in severe health effects on humans, affecting especially the respiratory system. As nanoparticles can pass through cell membranes, absorption occurs rapidly and affects many different parts and functions of the human body. While air filters are an effective method of reducing small-sized particles …


Investigating The Performance Of A New Type Of Multi-Element Airfoil For Wind Turbine Blade, Ahmed Elbaz Apr 2021

Investigating The Performance Of A New Type Of Multi-Element Airfoil For Wind Turbine Blade, Ahmed Elbaz

Mechanical Engineering

With the increasing demand on clean and sustainable source of electricity, wind energy represents attractive solution, and since that the performance of the turbine depends mainly on the blade airfoil aerodynamic characteristics, therefore improving Airfoil aerodynamic characteristics remain hot issue for research worldwide. The present paper proposes a new design of Multi-Element airfoil based on the symmetric airfoil NACA0021 geometry. The proposed Multi-Element airfoil design consists of two sub-airfoils with different overlap/gap, and orientation within the boundaries of the NACA0021 airfoil. The geometry generation method is explained and the aerodynamic performance of the proposed type is investigated using CFD. Nine …


Electric Hydrofoil Board, Zach Flood, Nick Potter, Wesley Sava, Trent Walker Apr 2021

Electric Hydrofoil Board, Zach Flood, Nick Potter, Wesley Sava, Trent Walker

Mechanical Engineering Senior Theses

The electric hydrofoil community has become very popular in recent years with its two major subsections being divided up into those that buy their boards commercially and those that build their own (the DIY community). The commercial boards are extremely expensive and can reach prices of over $12,000. This is the root cause of the rapidly growing DIY community who can build functioning boards for around $3000. Reducing this entry cost has made the sport much more accessible to new members and has allowed both the size of the community and awareness of the sport to increase. For this report …


Comparison Of Three Commercial Automatic Boom Height Systems For Agricultural Sprayers, Travis A. Burgers, John D. Gaard, Brian J. Hyronimus Apr 2021

Comparison Of Three Commercial Automatic Boom Height Systems For Agricultural Sprayers, Travis A. Burgers, John D. Gaard, Brian J. Hyronimus

Mechanical Engineering Faculty Publications

Automatic boom height systems reduce the variability of agricultural sprayer boom height. Consistent boom height is important for three key reasons: to reduce uneven spray dispersion if the boom is too low, to reduce spray droplet drift if the boom is too high, and to reduce damage to the boom or crop if the boom is too low. No data is available comparing commercial boom height systems. Three leading North American automatic boom height systems were compared: John Deere BoomTrac Pro (System A), Raven AutoBoom® XRT (System B), and Norac UC5TM Passive Roll (System C) on a John Deere R4045 …


Elastic Tail Propulsion At Low Re, Rafaela Barreto, Jennifer Miranti, Yoel Park, Elijah Vidal Apr 2021

Elastic Tail Propulsion At Low Re, Rafaela Barreto, Jennifer Miranti, Yoel Park, Elijah Vidal

Mechanical Engineering Senior Theses

The use of microswimmers, or microscopic swimming robots, in the medical field is becoming more sought after for applications such as targeted drug delivery and microsurgery. While such microswimmers do not yet exist for use on patients, many researchers are working on this front to make them a reality. One of the main challenges in making these microswimmers a reality is creating propulsion in a low Reynolds number environment. This project aims to create and test a prototype of a swimmer which employs 3D circular movement of its tail for propulsion in a very viscous fluid, mimicking a low Reynolds …


Relationship Between Thermal Conductivity And Free Electrons In Metal, Yansong Liu Apr 2021

Relationship Between Thermal Conductivity And Free Electrons In Metal, Yansong Liu

Senior Theses

An experiment was designed and conducted to explore the relationship between thermal conductivity with free electrons in metal. In the experiment, copper, iron, aluminum, and titanium rods with close diameters were used to carry out the experiment. Each rod was heated up by a heat unit at one end while cooled on the other end with a heat sink to maintain a steady state. DC current was applied to rods in the direction along, as well as against, the heat flow. Thermal conductivities were measured in these two situations for each rod. Results showed electrons do dominate thermal flow inside …


Design Of Smart Trashcan, Haoran Song Apr 2021

Design Of Smart Trashcan, Haoran Song

Senior Theses

A smart trashcan has been designed which can bring convenience to people for throwing their garbage away during the COVID-19 pandemic. A prototype is made from cardboard to demonstrate its function. This trashcan can sense people who are coming and leaving, and it can open and close automatically. The trashcan is powered by solar energy. A solar panel is mounted on top of the trashcan supporter. This design is specifically for use in China.


Portable Bicycle-Powered Refridgeration, David Gilbert, Zach Gotvald, Kerri-Ann Kamei, Lindsay Mcconville, Brooke Watson, Brian Woo-Shem Apr 2021

Portable Bicycle-Powered Refridgeration, David Gilbert, Zach Gotvald, Kerri-Ann Kamei, Lindsay Mcconville, Brooke Watson, Brian Woo-Shem

Mechanical Engineering Senior Theses

Lack of access to viable, life-saving vaccines is a major public health problem worldwide. Our project objective is to create a feasible, frugal, and environmentally conscious transportation solution for vaccines. Our design for a bicycle-powered refrigeration system can function in both urban environments and rural areas with unreliable electricity and minimal infrastructure. This is enabled by integrating power generation from bicycle kinetic energy, thermoelectric cooling, voltage regulation, temperature control, and heat dissipation subsystems. The system is enclosed in solid housing to protect fragile vials against bumps and crashes and can be adapted to fit onto existing bicycle racks.


Frugal Urban Greenhouse, Alexandra Rivera, Emma Rosicky, Connor Pearson Apr 2021

Frugal Urban Greenhouse, Alexandra Rivera, Emma Rosicky, Connor Pearson

Mechanical Engineering Senior Theses

This project collaborates with Valley Verde, a San Jose nonprofit organization, to build a greenhouse as a prototype for their Super Jardinero urban gardening program. This project also partners with the Frugal Innovation Hub, and has the goal to be affordable, rugged, and simple. The group created a design that ultimately met the desired metrics for weight, cost, and ergonomics. The design style makes hardening-off easier and specializes this greenhouse for seedlings, while structures currently on the market are built for larger plants. It is cheaper than any alternatives on the market and effectively meets Valley Verde’s needs.


Ninja 300 Motorcycle Luggage Rack, Mikel Hirigoyen, Ethan Gatchalian, Eric Tsuchiya Apr 2021

Ninja 300 Motorcycle Luggage Rack, Mikel Hirigoyen, Ethan Gatchalian, Eric Tsuchiya

Mechanical Engineering Senior Theses

The product is a motorcycle luggage rack compatible with the Kawasaki Ninja 300. This report elaborates on all aspects of the team’s work in developing this product. First, the motivations and foundational work for this project are discussed. Then, the team’s design of the entire product as a whole, and each of its subsystems are clearly laid out. System testing and results are also provided, followed by a cost breakdown of the whole process. Next, patents and engineering standards are listed as a documented justification for the team’s project. Finally, an overall project evaluation is conducted by the team.


Statistical Study Of The Effect Of Implementing An Airveyor System On The Warpage Of Injection Molded Closures, Charles Wesley Bozarth Apr 2021

Statistical Study Of The Effect Of Implementing An Airveyor System On The Warpage Of Injection Molded Closures, Charles Wesley Bozarth

Masters Theses & Specialist Projects

Berry Global in Bowling Green, Kentucky produces predominantly polypropylene container closures. One variant, the 83mm lined jar closure, is produced by first being injection molded, placed in work-in-progress (WIP) hold for 24 hours to cool, and then finished through the auxiliary liner operation into a final product. While this process is an effective method to produce a quality large-diameter closure and allows the polypropylene adequate time to cool without warping out of shape, the 24-hour WIP time and the manpower needed to accomplish this can negatively impact several business metrics as well as employee safety.

The purpose of this thesis …


Thermo Hydraulic Performance Of Polymer Double-Pipe Heat Exchanger For Single-Phase Heating/Cooling Application, Ahmed Mohamed Gafar Apr 2021

Thermo Hydraulic Performance Of Polymer Double-Pipe Heat Exchanger For Single-Phase Heating/Cooling Application, Ahmed Mohamed Gafar

Theses

This thesis details the model-based study carried out for understanding the thermal and hydraulic performance of double pipe heat exchangers with and without pin-fins; both counter and parallel flow configurations are considered in the study. The pin-fins are located on the outer wall of the inner pipe thereby extending into the annulus and in this study, the hot fluid is assumed to pass through the annulus. The model consists of multiple governing equations such as continuity equations, Navier-Stokes equations, and energy equations. A fluent module of Ansys Workbench is used for conducting the model-based study. Double pipe heat exchangers constructed …


Bending-Torsion Flutter Analysis Of A Viscoelastic Tapered Wing Carrying An Engine And Subjected To A Follower Thrust Force, Youssef Shaaban Abdelfattah Matter Apr 2021

Bending-Torsion Flutter Analysis Of A Viscoelastic Tapered Wing Carrying An Engine And Subjected To A Follower Thrust Force, Youssef Shaaban Abdelfattah Matter

Theses

Flutter, a dynamic divergent instability, is one of the significant phenomena of Aeroelasticity. This dangerous aeroelastic phenomenon can occur to any flexible structure subjected to aerodynamic forces such as aircraft wings, bridges, buildings, etc. It is important to analyze the flutter in order to predict the speed and frequency at which it occurs so that structural damages and failures can be avoided. This thesis is concerned with non-dimensional parametric modeling of the flutter of a viscoelastic tapered wing with an attached engine. The main objectives of this thesis are to determine regions of stability and boundaries of flutter speed and …


Development Of Piezoelectric Energy Harvesting System For Low-Frequency Vibrations, Mai Rabie Mahmoud Ismail Apr 2021

Development Of Piezoelectric Energy Harvesting System For Low-Frequency Vibrations, Mai Rabie Mahmoud Ismail

Theses

Harvesting energy from vibration sources has attracted the interest of researchers for the past three decades. Researchers have been working on the potential of achieving self-powered MEMS scale devices. Piezoelectric cantilever harvesters have caught the attention in this field because of the excellent combination of high-power density and compact structure. The main objective of this thesis is to develop a novel and optimum piezoelectric harvester system using lumped parameter model (LPM) for given vibration sources. The finite element model (FEM) is used in this work as an original approach to be utilized for optimal design optimization. Three types of validations …


Modelling And Control Of A Two-Link Rigid-Flexible Manipulator, Rahma Saeed Rasheed Alnajjar Apr 2021

Modelling And Control Of A Two-Link Rigid-Flexible Manipulator, Rahma Saeed Rasheed Alnajjar

Theses

The literature lacks data on the reliability of 3D models created by Autodesk Inventor software and imported to MATLAB Simulink software in comparison to mathematically generated models. In this contribution, a two-link rigid-flexible manipulator modelled in two different methods was demonstrated, one of which is using Lagrange equations and Finite Element Method to generate a mathematical model of the manipulator, and the other is creating a 3D model with the aid of Autodesk Inventor then import to MATLAB Simulink, both models were subsequently controlled by three types of controllers, conventional PID controller, LQR controller, and LQG controller. The research demonstrated …


Numerical Investigation Of Mesh-Based Enhancement Of Vapor Bubble Condensation, Omar Darwish Ali Alqadi Alhammadi Apr 2021

Numerical Investigation Of Mesh-Based Enhancement Of Vapor Bubble Condensation, Omar Darwish Ali Alqadi Alhammadi

Theses

The aim of this work is to study the vapor bubble condensation process and the enhancement technique via affecting bubbles dynamic using a mesh-based structure. The bubble dynamics and thermal behavior are studied by considering the heat and mass transfer through the bubble’s interface area between the vapor and liquid regions and the resulting condensation effects. The thermal characteristics of bubbles are observed considering the initial and final liquid temperatures. Additionally, the bubble dynamics are studied in terms of several parameters including the relative velocity of the bubble, bubble deformation, interfacial area, and the bubble diameters. The relation between the …


Thermal Evaluation Of Advanced Leading Edge For Rotating Gas Turbine Blade: Numerical And Experimental Investigations, Amin Safi Apr 2021

Thermal Evaluation Of Advanced Leading Edge For Rotating Gas Turbine Blade: Numerical And Experimental Investigations, Amin Safi

Dissertations

Gas turbine engines play a vital role in our life. Our power demand is significantly and continuously growing. One approach to improve thermal efficiency in gas turbine engines requires a higher turbine inlet gas temperature. Advanced gas turbine engines operate at high temperatures, around 2000 K. Since operating at high temperatures may compromise the blade structure integrity, different cooling systems are used in a turbine blades. One of the most efficient cooling techniques is impingement cooling, mostly used in the leading edge. The leading edge experiences the highest temperature in the blade exposed to the hottest gas.

Researchers studied different …


Damage Evolution And High-Rate Response Of High-Strength Concrete Under Triaxial Loading, Brett Williams Apr 2021

Damage Evolution And High-Rate Response Of High-Strength Concrete Under Triaxial Loading, Brett Williams

Mechanical Engineering Research Theses and Dissertations

The research presented in this study focuses on understanding fundamental mechanisms that drive material response under dynamic loading conditions. The objectives of the research were to: (1) to understand damage initiation and propagation in the bulk geomaterial under a variety of loading conditions and (2) to systematically investigate the strain rate effects on the triaxial compressive response of cementitious materials through the development of an innovative, first of its kind large-diameter (50 mm) triaxial Kolsky bar system.

The triaxial compressive response of high-strength concrete is needed to understand pressure-dependent material behavior, which is important for modeling extreme loading events. However, …


A Model-Based Systems Engineering Approach To E-Vtol Aircraft And Airspace Infrastructure Design For Urban Air Mobility, Heidi Selina Glaudel Apr 2021

A Model-Based Systems Engineering Approach To E-Vtol Aircraft And Airspace Infrastructure Design For Urban Air Mobility, Heidi Selina Glaudel

Mechanical & Aerospace Engineering Theses & Dissertations

This paper serves to contribute to Model-Based Systems Engineering (MBSE) by following the NASA Systems Engineering Handbook framework for a Systems Engineering (SE) design approach to an Electric Vertical Takeoff and Landing (e-VTOL) aircraft and the incorporating airspace infrastructure. The focus of this study is, by using the MBSE model created, to capture the technical requirements definition and design intent of the vehicle and airspace inclusive of community specific knowledge derived from the Federal Aviation Administration (FAA) NextGen Urban Air Mobility (UAM) Concept of Operations (ConOps) version 1.0. The stakeholder requirements derived from the FAA UAM NextGen ConOps will form …


Improved Strain Gage Instrumentation Strategies For Rotorcraft Blade Measurements, Timothy S. Davis Apr 2021

Improved Strain Gage Instrumentation Strategies For Rotorcraft Blade Measurements, Timothy S. Davis

Mechanical & Aerospace Engineering Theses & Dissertations

In this work, a new strategy is presented to wire, calibrate, and measure strain gages for rotor blade testing that will provide more information and is robust to individual gage loss. The additional information can be used in several ways. including reducing redundancy, offering rapid identification of damage locations, and in some cases reducing risk allowing tests to continue to collect calibrated data after one or more sensors have failed. This strategy replaces the classical four-gage full Wheatstone bridge with four separately wired quarter bridges that are combined into a full bridge in the data acquisition system using a calculated …


Drive Leg And Stride Leg Ground Reaction Forces Relationship To Medial Elbow Stress And Velocity In Collegiate Baseball Pitchers, Brett Smith Apr 2021

Drive Leg And Stride Leg Ground Reaction Forces Relationship To Medial Elbow Stress And Velocity In Collegiate Baseball Pitchers, Brett Smith

Biomedical Engineering Theses & Dissertations

This study examines several different kinetic variables in relation to pitch velocity and elbow varus torque in collegiate baseball pitchers using force plates, an inertial measurement unit, and a radar unit. The purpose of this study is to investigate the kinetic variables being measured and their relationship to pitch velocity and loads being placed on the medial elbow. Twelve collegiate baseball pitchers participated in this study, which was approved by the IRB. Impulse of the drive leg in the anterior-posterior direction, stride leg peak force in the anterior-posterior (AP) direction, elbow varus torque, and pitch velocity were all measured. Two …


The Drier Dryer, Daniel Anderson, Justin Lee, Thomas Morey, Josh Sunada Apr 2021

The Drier Dryer, Daniel Anderson, Justin Lee, Thomas Morey, Josh Sunada

Mechanical Engineering Senior Theses

With our product, The Drier Dryer, we aim to increase the efficiency of clothing dryers. This report contains an indepth look at the design approach we are taking to create our product. Our design utilizes a thermoelectric cooler combined with heat sinks and heat pipes to efficiently cool air to its dew point temperature and then reheat the air prior to sending it into a clothes dryer intake. Cooling the air to dew point temperature allows moisture to be removed from the air consequently decreasing the relative humidity. Throughout our design process we obtained simulation results providing a theoretical temperature …