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2021

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Articles 1141 - 1170 of 1560

Full-Text Articles in Mechanical Engineering

Clinical Evaluation Of Respiratory Rate Measurements On Copd (Male) Patients Using Wearable Inkjet-Printed Sensor, Ala'aldeen Al-Halhouli, Loiy Al-Ghussain, Osama Khallouf, Alexander Rabadi, Jafar Alawadi, Haipeng Liu, Khaled Al Oweidat, Fei Chen, Dingchang Zheng Jan 2021

Clinical Evaluation Of Respiratory Rate Measurements On Copd (Male) Patients Using Wearable Inkjet-Printed Sensor, Ala'aldeen Al-Halhouli, Loiy Al-Ghussain, Osama Khallouf, Alexander Rabadi, Jafar Alawadi, Haipeng Liu, Khaled Al Oweidat, Fei Chen, Dingchang Zheng

Mechanical Engineering Graduate Research

Introduction: Chronic Obstructive Pulmonary Disease (COPD) is a progressive disease that causes long-term breathing problems. The reliable monitoring of respiratory rate (RR) is very important for the treatment and management of COPD. Based on inkjet printing technology, we have developed a stretchable and wearable sensor that can accurately measure RR on normal subjects. Currently, there is a lack of comprehensive evaluation of stretchable sensors in the monitoring of RR on COPD patients. We aimed to investigate the measurement accuracy of our sensor on COPD patients. Methodology: Thirty-five patients (Mean ± SD of age: 55.25 ± 13.76 years) in different stages …


First-Order Comprehensive Adjoint Sensitivity Analysis Methodology For Critical Points In Coupled Nonlinear Systems. I: Mathematical Framework, Dan Gabriel Cacuci Jan 2021

First-Order Comprehensive Adjoint Sensitivity Analysis Methodology For Critical Points In Coupled Nonlinear Systems. I: Mathematical Framework, Dan Gabriel Cacuci

Faculty Publications

This work presents the novel first-order comprehensive adjoint sensitivity analysis methodology for critical points (1st-CASAM-CP), which enables the exact and efficient computation of the first-order sensitivities of responses defined at critical points (maxima, minima, saddle points) of coupled nonlinear models of physical systems characterized by imprecisely known parameters underlying the models, boundaries, and interfaces between the coupled systems. Responses defined at critical points are important in many applications, including system optimization, safety analyses and licensing. For the design and licensing of nuclear reactors, such essentially important responses include the maximum temperatures of the fuel and cladding in hot channels. The …


First-Order Comprehensive Adjoint Sensitivity Analysis Methodology For Critical Points In Coupled Nonlinear Systems. Ii: Application To A Nuclear Reactor Thermal-Hydraulics Safety Benchmark, Dan Gabriel Cacuci Jan 2021

First-Order Comprehensive Adjoint Sensitivity Analysis Methodology For Critical Points In Coupled Nonlinear Systems. Ii: Application To A Nuclear Reactor Thermal-Hydraulics Safety Benchmark, Dan Gabriel Cacuci

Faculty Publications

Responses defined at critical points are particularly important for reactor safety analyses and licensing (e.g., the maximum fuel and/or clad temperature). The novel mathematical framework of the first-order comprehensive adjoint sensitivity analysis methodology for critical points (1st-CASAM-CP) is applied in this work to develop a reactor safety thermal-hydraulics benchmark model which admits exact closed-form expressions for the adjoint functions and for the first-order sensitivities of responses defined at critical points (maxima, minima, saddle points) in physical systems characterized by imprecisely known parameters, external and internal boundaries. This benchmark model is designed for verifying the capabilities and accuracies of computational tools …


Concrete Delamination Depth Estimation Using A Noncontact Mems Ultrasonic Sensor Array And An Optimization Approach, Homin Song, Jinyoung Hong, Hajin Choi, Jiyoung Min Jan 2021

Concrete Delamination Depth Estimation Using A Noncontact Mems Ultrasonic Sensor Array And An Optimization Approach, Homin Song, Jinyoung Hong, Hajin Choi, Jiyoung Min

Michigan Tech Publications, Part 1

In this study, we present a method to estimate the depth of near-surface shallow delamination in concrete using a noncontact micro-electromechanical system (MEMS) ultrasonic sensor array and an optimization-based data processing approach. The proposed approach updates the bulk wave velocities of the tested concrete element by solving an optimization problem using reference ultrasonic scanning data collected from a full-depth concrete region. Subsequently, the depth of concrete delamination is estimated by solving a separate optimization problem. Numerical simulations and laboratory experiments were conducted to evaluate the performance of the proposed ultrasonic data processing approach. The results demonstrated that the depth of …


Numerical Analysis Of Ultrasonic Multiple Scattering For Fine Dust Number Density Estimation, Homin Song, Ukyong Woo, Hajin Choi Jan 2021

Numerical Analysis Of Ultrasonic Multiple Scattering For Fine Dust Number Density Estimation, Homin Song, Ukyong Woo, Hajin Choi

Michigan Tech Publications, Part 1

In this study, a method is presented for estimating the number density of fine dust particles (the number of particles per unit area) through numerical simulations of multiply scattered ultrasonic wavefields. The theoretical background of the multiple scattering of ultrasonic waves under different regimes is introduced. A series of numerical simulations were performed to generate multiply scattered ultrasonic wavefield data. The generated datasets are subsequently processed using an ultrasound data processing approach to estimate the number density of fine dust particles in the air based on the independent scattering approximation theory. The data processing results demonstrate that the proposed approach …


Numerical Reconstruction Of Spalled Particle Trajectories In An Arc-Jet Environment, Raghava S. C. Davuluri, Sean C. C. Bailey, Kaveh A. Tagavi, Alexandre Martin Jan 2021

Numerical Reconstruction Of Spalled Particle Trajectories In An Arc-Jet Environment, Raghava S. C. Davuluri, Sean C. C. Bailey, Kaveh A. Tagavi, Alexandre Martin

Mechanical Engineering Faculty Publications

To evaluate the effects of spallation on ablative material, it is necessary to evaluate the mass loss. To do so, a Lagrangian particle trajectory code is used to reconstruct trajectories that match the experimental data for all kinematic parameters. The results from spallation experiments conducted at the NASA HYMETS facility over a wedge sample were used. A data-driven adaptive methodology was used to adapts the ejection parameters until the numerical trajectory matches the experimental data. The preliminary reconstruction results show that the size of the particles seemed to be correlated with the location of the ejection event. The size of …


Sensitivity And Estimation Of Flying-Wing Aerodynamic, Propulsion, And Inertial Parameters Using Simulation, Jaden Thurgood, Douglas F. Hunsaker Jan 2021

Sensitivity And Estimation Of Flying-Wing Aerodynamic, Propulsion, And Inertial Parameters Using Simulation, Jaden Thurgood, Douglas F. Hunsaker

Mechanical and Aerospace Engineering Student Publications and Presentations

This paper explores the difficulties of aircraft system identification, specifically parameter estimation, for a rudderless aircraft. A white box method is used in conjunction with a nonlinear six degree-of-freedom aerodynamic model for the equations of motion in order to estimate 33 parameters that govern the aerodynamic, inertial, and propulsion forces within the mathematical model. The analysis is conducted in the time-domain of system identification. Additionally, all the parameters are estimated using a single flight rather than a series of shorter flights dedicated to estimating specific sets of parameters as is typically done. A final flight plan is developed with a …


Practical Implementation Of A General Numerical Lifting-Line Method, Cory D. Goates, Douglas F. Hunsaker Jan 2021

Practical Implementation Of A General Numerical Lifting-Line Method, Cory D. Goates, Douglas F. Hunsaker

Mechanical and Aerospace Engineering Student Publications and Presentations

A general numerical lifting-line method provides corrections to overcome the singularities inherent in the lifting-line downwash integrals in certain cases. These singularities have previously limited the scope of lifting-line theory to straight wings not in sideslip; in all other cases, more traditional numerical approaches to solving Prandtl's hypothesis fail to grid converge. However, this general numerical lifting-line method grid converges even for swept wings and wings in sideslip. In the current work, we apply the general numerical lifting-line method to any number of wings with arbitrary geometry. We also provide a dimensional derivation of the basic general numerical lifting-line equations …


3d-Printed Wings With Morphing Trailing-Edge Technology, Benjamin C. Moulton, Douglas F. Hunsaker Jan 2021

3d-Printed Wings With Morphing Trailing-Edge Technology, Benjamin C. Moulton, Douglas F. Hunsaker

Mechanical and Aerospace Engineering Student Publications and Presentations

In recent years, various groups have attempted to improve aircraft efficiency using wings with morphing trailing-edge technology. Most of these solutions are difficult to manufacture or have limited morphing capability. The present paper outlines a research effort to develop an easy to manufacture, fully 3D-printed morphing wing. This approach is advantageous due to the low cost, minimal man-hours required for manufacturing, and speed at which design iterations can be explored. Several prototypes were designed and tested and lessons learned from these iterations have been documented. Additionally, printer settings have been tested and catalogued to assist others attempting to reproduce these …


Comparison Of Theoretical And High-Fidelity Aerostructural Solutions, Jeffrey D. Taylor, Douglas F. Hunsaker Jan 2021

Comparison Of Theoretical And High-Fidelity Aerostructural Solutions, Jeffrey D. Taylor, Douglas F. Hunsaker

Mechanical and Aerospace Engineering Student Publications and Presentations

As contemporary aerostructural research in aircraft design trends toward high-fidelity computational methods, aerostructural solutions based on theory are often neglected or forgotten. In fact, in many modern aerostructural wing optimization studies, the elliptic lift distribution is used as a benchmark in place of theoretical aerostructural solutions with more appropriate constraints. In this paper, we review several theoretical aerostructural solutions that could be used as benchmark cases for wing design studies, and we compare them to high-fidelity solutions with similar constraints. Solutions are presented for studies with 1) constraints related to the wing integrated bending moment, 2) constraints related to the …


Characterization Of The Common Research Model Wing For Low-Fidelity Aerostructural Analysis, Jeffrey D. Taylor, Douglas F. Hunsaker Jan 2021

Characterization Of The Common Research Model Wing For Low-Fidelity Aerostructural Analysis, Jeffrey D. Taylor, Douglas F. Hunsaker

Mechanical and Aerospace Engineering Student Publications and Presentations

A characterization of the Common Research Model (CRM) wing for low-fidelity aerostructural optimization is presented. The geometric and structural properties are based on the CAD geometries and finite-element models for the CRM wing and the undeflected Common Research Model Wing (uCRM). Three approximations are presented for the elastic axis from previously-published studies on wing boxes similar to the uCRM, and approximations of the flexural and torsional rigidity are presented from a previously-published study using the uCRM wing. The characterization presented in this paper is intended to be used within low-fidelity aerostructural analysis tools to facilitate rapid design optimization and exploratory …


Development Of A Combined Thermal Management And Power Generation System Using A Multi-Mode Rankine Cycle, Nathaniel M. Payne Jan 2021

Development Of A Combined Thermal Management And Power Generation System Using A Multi-Mode Rankine Cycle, Nathaniel M. Payne

Browse all Theses and Dissertations

Two sub-systems that present a significant challenge in the development of high performance air vehicle exceeding speeds of Mach 5 are the power generation and thermal management sub-systems. The air friction experienced at high speeds, particularly around the engine, generates large thermal loads that need to be managed. In addition, traditional jet engines do not operate at speeds greater than Mach 3, therefore eliminating the possibility of a rotating power generator. A multi-mode water-based Rankine cycle is an innovative method to address both of these constraints of generating power and providing cooling. Implementing a Rankine cycle-based system allows for the …


Wetting And Brazing Of Yig Ceramics Using Ag–Cuo–Tio2 Metal Filler, Wanqi Zhao, Shuye Zhang, Jian Yang, Tiesong Lin, Dusan P. Sekulic, Peng He Jan 2021

Wetting And Brazing Of Yig Ceramics Using Ag–Cuo–Tio2 Metal Filler, Wanqi Zhao, Shuye Zhang, Jian Yang, Tiesong Lin, Dusan P. Sekulic, Peng He

Mechanical Engineering Faculty Publications

The wetting and brazing of Y3Fe5O12 (YIG) ceramics with a Ag–8CuO–2TiO2 filler was investigated for the first time. For comparison, the wettability of a Ag–10CuO filler on YIG ceramics was similarly investigated. The Ag–8CuO–2TiO2 filler has an equilibrium contact angle of approximately 31 °C on the YIG substrate at 1000 °C; thus, its wettability is excellent. Moreover, its wettability exceeds that of Ag–10CuO. The microstructure and the interfacial structure between the filler and the substrate were determined using scanning electron microscopy, X-ray diffraction, EPMA and transmission electron microscopy. The liquid Ag–8CuO–2TiO2 filler …


Asme Rc Baja Racer, Chesna Kern Jan 2021

Asme Rc Baja Racer, Chesna Kern

All Undergraduate Projects

The American Society of Mechanical Engineers (ASME) holds a competition at their annual conference for college students to design an RC car that will compete in sprint, slalom, and obstacle course races. The RC Baja car was designed to complete every event in the competition with a focus on the obstacle course due to the anticipated impacts inflicted on the project car by jumps and other obstacles. The project was a collaborative effort. This presentation focuses on the chassis and suspension while Gizan Gando will present about the drivetrain. The drop and frontal impact test requirements guided the design process …


Jcati - Drive System, Tim Boswell Jan 2021

Jcati - Drive System, Tim Boswell

All Undergraduate Projects

Each year, Mechanical Engineering Technology students receive a grant from The Joint Center for Aerospace Technology Innovation (JCATI) to engineer a device that is capable of breaking down carbon fiber trimmings for recycling. The students who received the grant this year have redesigned portions of the existing system in an attempt to solve issues that have kept the system from working properly in the past. Though much collaboration between group members has been needed, each member has been responsible for their own portion of the project. The purpose of this portion of the project has been to address binding and …


Rc Baja-Drivetrain & Steering, Tucker Odegaard Jan 2021

Rc Baja-Drivetrain & Steering, Tucker Odegaard

All Undergraduate Projects

There was a need for an RC car that would turn the power of a brushless motor into torque to the wheels, in order for it to move forward and backward. The car needed to meet given requirements in order to compete in the annual American Society of Mechanical Engineers (ASME) RC Baja competition. The team requirements were to reach a top speed of 20 mph, turn 60° in both directions, survive a three-foot drop, and spend no more than $500 total on the project. In order to meet the requirements, the device chosen was an RC Baja that had …


Pulse Decay Thermal Conductivity Device, Matthew Schrenk Jan 2021

Pulse Decay Thermal Conductivity Device, Matthew Schrenk

All Undergraduate Projects

Currently, there are several ways in which thermal conductivity can be calculated or assessed on a given material. However, with each method of testing comes potential limitations such as size, material state, complexity, and time. The goal of this study was to develop a pulse heated thermistor that would reduce all four limitations, thus provide precise and timely results regardless of the material state and size. A thermistor is resistor which changes resistance in accordance to temperature. To achieve the design, heat transfer and electrical methods were applied. As with all resistors, heat is dissipated across the element and released …


Rc Baja, Ryder Satak Jan 2021

Rc Baja, Ryder Satak

All Undergraduate Projects

American Society of Mechanical Engineers (ASME) hosts an RC Baja competition yearly at Central Washington University where schools from around the state gather to compete. The competition is based and scored from three different events: drag race, slalom, and a Baja course. Performing well in both the competition and other various tests will deem the car successful. The differential and drive train are two important features that allow the car to function properly. Using Solidworks 3D software and a 3D printer, the engineers were able to design functional components. The differential is designed to allow the rear wheels to spin …


Articulated Balsa Wood Bridge, Isaac Chavez Ramirez Jan 2021

Articulated Balsa Wood Bridge, Isaac Chavez Ramirez

All Undergraduate Projects

The project chosen was the challenge of designing and constructing an articulating Balsa Wood Bridge that would withstand a minimum load of 18.9 kg. The first step was to find which design will best work for the requirements; a decision matrix has been used in this decision. Analyses were completed to find the geometry of each part that will support the load. The project construction was in sequences: the first sequence was the construction of each component, then the construction of 3 subassemblies, and finally was the construction of the entire project. The last part of the project was programming …


Jcati Base Plate, Jacob Atamian Jan 2021

Jcati Base Plate, Jacob Atamian

All Undergraduate Projects

Students of the Mechanical Engineering Technology (MET) program at Central Washington University have contributed to an ongoing Carbon Fiber Recycler project funded by the Joint Center for Aerospace Technology Innovation (JCATI). The goal of this project was to modify the existing recycling system to produce a higher success rate of recycled carbon composite material. This report focuses on increasing the rigidity of the crushing gears so that the deflection occurring among the components during operation was below 0.005 inches to ensure proper operating conditions. The operating speed of the crushing gears was 2.5 rpm with a crushing load of 10,500 …


R/C Baja Chassis And Suspension, Donovan Dueber Jan 2021

R/C Baja Chassis And Suspension, Donovan Dueber

All Undergraduate Projects

A team made up of two students have developed a unique design of a RC Baja Car to optimize functionality and performance. A Baja car is a remote controlled 1/10 scale car that is used for recreation or competition, usually meant for competing in the American Society of Mechanical Engineers (ASME) Baja car competition against various teams. The objective for the project was to create a unique suspension different from previous individual’s projects by creating a two-type suspension. This was completed by having a coil suspension in the front which allows more travel in the suspension of the car and …


Jcati Carbon Fiber Recycling Shredder, Benjamin Cooley Jan 2021

Jcati Carbon Fiber Recycling Shredder, Benjamin Cooley

All Undergraduate Projects

Once carbon fibers are cast into a resin and used in a composite material, retrieving those fibers can be a difficult task. However, it is beneficial to recycle and reuse the fibers from old unneeded components rather than pay the cost of acquiring new ones. The Joint Center for Aerospace Technology Innovation (JCATI) carbon fiber recycling device condenses the multistep process of extracting the fibers by integrating all steps into one automated device. In the previous version of the device, the cutting blades turned the long composite strips into thin fingers but did not sever them across the width.

The …


Balsa Wood Drawbridge, Kyle Engebretson Jan 2021

Balsa Wood Drawbridge, Kyle Engebretson

All Undergraduate Projects

Which truss design is best suited to a drawbridge when precision equipment is unavailable for the construction process and what design is suitable for the articulation system? To address this problem, several different designs were considered for a truss made of balsa wood. Initially a warren truss, a k-truss, and a bowstring truss were considered. The designs were evaluated using a decision matrix, the winning design was produced and tested. The testing methods used were a mass limit of the bridge, a minimum length requirement, loading requirements, and a minimum height for the roadway to reach when raised. Various other …


Balsa Wood Bridge, Joshua Nye Jan 2021

Balsa Wood Bridge, Joshua Nye

All Undergraduate Projects

The project requires the individual to design and construct a truss bridge made from balsa wood and wood glue to perform several objectives. The main objectives are to articulate the bridge by raising it, to conform to dimensional requirements, to allow a vehicle to travel along the road deck, and to hold a minimum load. The bridge must be able to articulate in two different ways. First, the articulation system can lift the road deck vertically while on top of the bridge. Second, raise the bridge with a pivot when the articulation system is placed at the specified end of …


Thermal Conductivity Measuring System (Tcoms), Lucas Hill Jan 2021

Thermal Conductivity Measuring System (Tcoms), Lucas Hill

All Undergraduate Projects

The Mechanical Engineering Technology department at Central Washington University is lacking a method to reliably measure the thermal conductivity of bulk materials, with dimensions of at least a 1 cm radius, within a teaching environment. Thermal Conductivity Measuring System (TCoMS) will be a useful tool to perform these measurements as it is able to obtain measurement readings for materials between 0 C and 50 C within 20 seconds. TCoMS will accomplish this by using the pulse decay method of measuring thermal conductivity, a form of transient heat transfer analysis. This method is performed by generating a pulse of heat at …


Balsa Wood Bridge, Anndie Watterson Jan 2021

Balsa Wood Bridge, Anndie Watterson

All Undergraduate Projects

A model for a strong bridge that could span a set distance and rise up to allow for passage underneath was requested, and specifications for the design were given. The model bridge was designed out of balsa wood to meet all the requirements. Using structural and material analysis and simple mechanical designs, a bridge was designed and constructed out of balsa wood, wood glue, and metal components used for articulation that met all of the criteria set by the assigner. The bridge was tested to ensure all specifications were met. The resulting bridge can hold 20kg of weight suspended from …


Thermal Conductivity Measuring Device, Kyle Saalfeld Jan 2021

Thermal Conductivity Measuring Device, Kyle Saalfeld

All Undergraduate Projects

The thermal conductivity measuring device is used to measure thermal conductivity of solids, liquids, and food products. Thermal conductivity is a material property that determines the rate at which heat disperses through a material. This determines how well insulation works, what materials are used as heat sinks, refrigeration, and how thoroughly food is cooked. The device measures thermal conductivity by heating up a thermistor bead using a high magnitude current for a measured duration and allowing the given heat to disperse; meeting the goal of designing a device that can easily measure the conductivity. Additional requirements of this device include …


Rc Baja Car: Suspension And Chassis, Colton Hague Jan 2021

Rc Baja Car: Suspension And Chassis, Colton Hague

All Undergraduate Projects

An RC Baja car was designed and manufactured to compete in the ASME RC Baja competition. The American Society of Mechanical Engineering (ASME) Baja competition is a time trial that has a variety of obstacles like jumps, rocks, and turns. The objective of the project was to improve the performance of the suspension and chassis while offering a variety of different adjustments that can be made to fit a given terrain. To begin the design process, a benchmark car was selected, and research was performed on trophy trucks to incorporate suspension features into the design. Using engineering methods, analyses was …


A Molecular Dynamic Study On The Piezoelectric Properties Of Bulk Zns And Nanobelts, Rui Xie Jan 2021

A Molecular Dynamic Study On The Piezoelectric Properties Of Bulk Zns And Nanobelts, Rui Xie

Theses, Dissertations and Capstones

In this thesis we proved the feasibility of using classical atomic simulations, namely molecular dynamics and molecular statics, to study the piezoelectric properties of bulk and nanobelts ZnS structures, by utilizing the core-shell atomic potential model. Based on the verification of bulk and nanobelts ZnO piezoelectric constants, utilizing LAMMPS scripts and the Nyberg et al. core-shell potential, we reported the bulk ZnS piezoelectric constants calculated using three different classical interatomic core-shell ZnS potentials; the Wright and Jackson (1995) potential, the Wright and Gale (2004) potential, and the Namsani et al. (2015) potential. The simulation results showed that the Wright and …


Performance Of A Dual Plane Airfoil Model With Varying Gap, Stagger, And Decalage Using Pressure Measurements And Particle Image Velocimetry, Salome Kenneth Nunes Jan 2021

Performance Of A Dual Plane Airfoil Model With Varying Gap, Stagger, And Decalage Using Pressure Measurements And Particle Image Velocimetry, Salome Kenneth Nunes

Browse all Theses and Dissertations

The dual-plane airfoil has been adopted in the design of aircraft wings, wind turbine blades, and propellers. The purpose of this research is to investigate the most important design parameters of a dual-plane airfoil model for the best aerodynamic performance, such as gap, stagger, and decalage. The dual-plane airfoil model was designed using the S826 profile. A mechanical mechanism with electrical actuator control is particularly designed to alter the gap and stagger smoothly, as well as the angle of attack (AOA) for each airfoil. It results in a gap range of 1.38c to 2.17c, a stagger range of -0.75c to …