Mechanical Engineering Commons^™

Development Of A Method To Model An Enclosed, Coaxial Carbon Nanotube Speaker With Experimental Validation, Suraj Prabhu

Dissertations, Master's Theses and Master's Reports

Carbon nanotube (CNT) speakers operate on heat as compared to conventional loudspeakers that operate on vibration. CNT speakers are extremely lightweight, stretchable, flexible, and have high operating temperatures. Due to these advantages, CNT speakers are being considered as a viable replacement option for conventional loudspeakers. One such application is automotive exhaust noise control. The goal of this research is to design an enclosed, coaxial CNT speaker and to develop a modeling method to model this speaker using COMSOL Multiphysics.

As part of this research, an enclosed, coaxial CNT speaker was designed and manufactured for automotive exhaust noise control. The first …

Convective Heat Transfer Enhancement Of A Channel-Flow Using Synthetic Jet, Pravesh Pokharel

Electronic Theses and Dissertations

A transient numerical simulation was carried out using ANSYS Fluent, to investigate the convection heat transfer enhancement of the air channel flow using the synthetic jet. Keeping the dimensional parameters of the domain fixed, averaged channel flow velocity was varied up to 3m/s. The diaphragm displacement effect on synthetic jet was studied, ranging the peak-to-peak displacement value from 0.4 to 1.2mm with increment of 0.4mm. Three locations were studied to determine the best operating location of the synthetic jet. Also, frequencies were varied up to 200Hz with every 50Hz increment, from initial condition of 50Hz. It was found that the …

The Development Of A Wearable Device For Relieving The Lower Leg Muscles Fatigue, Warawarin Nitirojntanad

Chulalongkorn University Theses and Dissertations (Chula ETD)

Standing is considered one of the most practical working postures since our limbs have the greatest range of motion. Standing yields plenty of benefits, however, prolonged standing could lead not only to discomfort but also to musculoskeletal disorders (MSDs). This study aims to design and develop a device that could help relieve muscle fatigue in the lower leg as the effects of prolonged standing as well as to evaluate the proposed device. The basics of fatigue, the consequences of prolonged standing and walking, and a review of the existing interventions to cope with muscle fatigue are used in designing the …

Test 2231: John Deere 8r 250, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Test 2084a: John Deere 7r 270, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Evaluation Of Murrell’S Ekf-Based Attitude Estimation Algorithm For Exploiting Multiple Attitude Sensor Configurations, Sharanabasaweshwara Asundi, Norman Fitz-Coy, Haniph Latchman

Mechanical & Aerospace Engineering Faculty Publications

Pico- and nano-satellites, due to their form factor and size, are limited in accommodating multiple or redundant attitude sensors. For such satellites, Murrell's implementation of the extended Kalman filter (EKF) can be exploited to accommodate multiple sensor configurations from a set of non redundant attitude sensors. The paper describes such an implementation involving a sun sensor suite and a magnetometer as attitude sensors. The implementation exploits Murrell's EKF to enable three sensor configurations, which can be operationally commanded, for satellite attitude estimation. Among the three attitude estimation schemes, (i) sun sensor suite and magnetometer, (ii) magnetic field vector and its …

Mechanism For The Unfolding Of The Top7 Protein In Steered Molecular Dynamics Simulations As Revealed By Mutual Information Analysis, Ognjen Perišić, Willy Wriggers

Mechanical & Aerospace Engineering Faculty Publications

We employed mutual information (MI) analysis to detect motions affecting the mechanical resistance of the human-engineered protein Top7. The results are based on the MI analysis of pair contact correlations measured in steered molecular dynamics (SMD) trajectories and their statistical dependence on global unfolding. This study is the first application of the MI analysis to SMD forced unfolding, and we furnish specific SMD recommendations for the utility of parameters and options in the TimeScapes package. The MI analysis provided a global overview of the effect of perturbation on the stability of the protein. We also employed a more conventional trajectory …

Digital Twins For Manufacturing And Logistics Systems: Is Simulation Practice Ready?, Francesco Longo, Antonio Padovano, Letizia Nicoletti, Mohaiad Elbasheer, Rafael Diaz

VMASC Publications

This article provides a theoretical contribution to the state-of-the-art of digital twins for manufacturing and logistics systems. The primary goal of this paper is to draw attention to the gap between the theoretical framework of digital twins in manufacturing and supply chain and their practical implementation from a simulation modeling point of view. Therefore, highlighting the recent innovations in the simulation practice that could provide the basis for digital twins with high levels of data integration, automation, and smart capabilities. This study follows a comparative approach to analyzing theoretical and technical readiness for developing digital twins with high fidelity and …

Assessing The Comfort Of Earplugs: Development And Validation Of The French Version Of The Coprod Questionnaire, Jonathan Terroir, Nellie Perrin, Pascal Wild, Olivier Doutres, Franck Sgard, Chantal Gauvin, Alessia Negrini

Études primaires

Earplugs are a common form of protection for workers exposed to hazardous noise levels. Their comfort directly impacts the effective protection by influencing their consistent and correct use. Nevertheless, comfort definition may vary according to the studies. Thus, a previous review of the literature has shown that to improve our understanding of perceived comfort and to reduce measurement variability, it is advisable to consider comfort through a multidimensional construct (physical, acoustical, functional and psychological). On this basis, the COPROD (COnfort des PROtections auDitives/COmfort of hearing PROtection Devices) questionnaire was developed. It is intended for people working in noisy environments. Nine …

Generic Design Methodology For Smart Manufacturing Systems From A Practical Perspective. Part Ii—Systematic Designs Of Smart Manufacturing Systems, Zhuming Bi, Wen-Jun Zhang, Chong Wu, Chaomin Luo, Lida Xu

Information Technology & Decision Sciences Faculty Publications

In a traditional system paradigm, an enterprise reference model provides the guide for practitioners to select manufacturing elements, configure elements into a manufacturing system, and model system options for evaluation and comparison of system solutions against given performance metrics. However, a smart manufacturing system aims to reconfigure different systems in achieving high-level smartness in its system lifecycle; moreover, each smart system is customized in terms of the constraints of manufacturing resources and the prioritized performance metrics to achieve system smartness. Few works were found on the development of systematic methodologies for the design of smart manufacturing systems. The novel contributions …

Study Of The Mechanlsm Of Flow-Induced Vibrations Of A Cylinder In Proximity To A Wall, Jonathan M. Chambers

Master’s Theses

Flexible bluff bodies exposed to a uniform fluid flow undergo vibration due to vortex-shedding from the body. This phenomenon is known as vortex-induced vibration (VIV). Structural members, such as cables, conduits, and pipes, are susceptible to VIV. Vortex-induced vibrations result in structural stresses due to elastic structural deformation from the flow-induced loading. Cylindrical structures in proximity to planar surfaces can undergo vortex-induced vibrations when the gap between the cylinder and the planar surfaces is above a critical value. This laboratory study investigated the mechanism of vibration and planar wall proximity effect on the cylinder response to the vortex shedding process. …

Fluid-Wall Interactions In Pseudopotential Lattice Boltzmann Models, Cheng Peng, Luis F. Ayala, Orlando M. Ayala

Engineering Technology Faculty Publications

Designing proper fluid-wall interaction forces to achieve proper wetting conditions is an important area of interest in pseudopotential lattice Boltzmann models. In this paper, we propose a modified fluid-wall interaction force that applies for pseudopotential models of both single-component fluids and partially miscible multicomponent fluids, such as hydrocarbon mixtures. A reliable correlation that predicts the resulting liquid contact angle on a flat solid surface is also proposed. This correlation works well over a wide variety of pseudopotential lattice Boltzmann models and thermodynamic conditions.

Let's Collaborate! The Importance Of Cybersecurity Pathways And Their Accessibility, Vukica Jovanovic, Otilia Popescu, Murat Kuzlu, Petros Katsioloudis

Engineering Technology Faculty Publications

[Introduction] I am very passionate about inspiring a new generation of the STEM workforce. Going through the engineering pathway myself since 9th grade, I have seen the value of technical education and early career choice. In high school, I learned so much about math and science, but also about the technical and applied aspects of STEM professions. I had one apprenticeship in electrical power and aluminum mill companies where I explored how the concepts from the classes convey to the real world. It was so much easier to learn all the equations and different aspects of technology from the textbook …

One-Dimensional Lateral Force Anisotropy At The Atomic Scale In Sliding Single Molecules On A Surface, Yuan Zhang, Daniel J. Trainer, Badri Narayanan, Yang Li, Anh T. Ngo, Sushila Khadka, Arnab Neogi, Brandon Fisher, Larry A. Curtiss, Subramanian K.R.S. Sankaranarayanan, Saw Wai Hla

Physics Faculty Publications

Using a q+ atomic force microscopy at low temperature, a sexiphenyl molecule is slid across an atomically flat Ag(111) surface along the direction parallel to its molecular axis and sideways to the axis. Despite identical contact area and underlying surface geometry, the lateral force required to move the molecule in the direction parallel to its molecular axis is found to be about half of that required to move it sideways. The origin of the lateral force anisotropy observed here is traced to the one-dimensional shape of the molecule, which is further confirmed by molecular dynamics simulations. We also demonstrate that …

Development Of A Heavy-Duty Aluminum Rail Hole Punch Manufacturing Fixture, Reese Hawthorne

Williams Honors College, Honors Research Projects

This report details the development and testing of an improved replacement for a worn manufacturing fixture which was used to position the location of four drilled holes on the outside of a heavy-duty aluminum rail. Commissioned by JohnDow Industries, the new process improves upon the old one by implementing an electro-hydraulic punch and new locating fixture. The new design produced higher quality slots, decreased cycle time by 15%, and aimed to improve the ergonomics of the process for the employees. All these factors contributed to making the aluminum rails a high-quality end product for JohnDow’s customers. Further iteration of the …

Customizable Armor Set, Olivia Reedy

Williams Honors College, Honors Research Projects

This project is intended to help people who make costume armor by reducing the amount of time and money it takes to create a set of armor. Making armor can take a lot of resources for beginners, and this project is intended to help hobbyists with that process. This customizable armor set goes through the engineering design process, from the initial design of the parts to creating the prototype using vacuum forming. The prototype armor can be painted and adhered to using acrylic paint and contact cement, respectively, and fits three sizes of small, medium, and large.

Design For Additive Manufacturing (3d Printing), Michael O'Donnell, Michael J. Levy

Williams Honors College, Honors Research Projects

The goal of this project is to study the performance of a 3D printed mechanical part subjected to topology optimization. A part that is somewhat complex in its load bearing and geometry will be selected. That part will then be designed, finite element analysis will be performed on it to optimize its topology, and then it will be 3D printed and tested. The goal of topology optimization is to either save material cost and/or part weight due to the ability of 3D printing to manufacture parts with complex and obscure geometry.

Camper Conversion, Owen Christian Hafler, Zebediah Paul Benedict Zehentbauer, Madilyn Beatrice Willis, Zachary Eli Owen, Justin Robert Nicholas

Williams Honors College, Honors Research Projects

The COVID-19 pandemic of 2020-2021 has seen hundreds of thousands sequestered in quarantine for long periods of time. When quarantined in an urban setting, many cannot leave their respective apartment buildings which only adds to the strain of isolation. In the context of isolation, the design team of Hafler, Nicholas, Owen, Willis, and Zehentbauer personally sought to incorporate their individual enthusiasm for nature with the benefits of living off-grid. After initial research and deliberation, the team discovered the “Skoolie” community and the plans for a mobile tiny home began production.

The team outlined the design project as the full design, …

Design And Testing Of A Feed-Forward Control System For Deployable Vortex Generators Dependent On Angle Of Attack, Solomon B. Whitmire, Christopher J. Chapanar, Kirklin M. Anderson, Nickalus R. Amon, Daniel W. Chech

Williams Honors College, Honors Research Projects

A vortex generator (VG hereafter) is a common feature of an aircraft wing that disturbs the flow on the leading edge of the wing, thus energizing the boundary layer and reducing flow separation. For an aircraft experiencing flow separation, VGs can increase the lift-to-drag ratio of the wing and prevent stall; however, if flow separation isn’t an issue, the unnecessary frontal area of the VGs has the potential to produce parasitic drag. This study seeks to determine whether the use of a deployment system can improve the performance of VG’s by raising or lowering them depending on the angle of …

Smart Home Pet Feeder, Andrew Markja, Simona Zdravev, Timothy Zubek, Christian Jackson

Williams Honors College, Honors Research Projects

The goal of this project was to design a Smart Home Pet Feeder that will allow the owner to feed their pet using 4 different methods. The methods are: manually, scheduled, app/url, Alexa/Google. The advantages of this design are that it will become convenient for pet owners who are busy and unable to make it back to their house to feed their pets remotely or for those who enjoy the use of technology from within their home for no-trouble feeding.

Dji Drone Modification, Sean Lacey, Seth Mancuso, Bryce Mckenzie

Williams Honors College, Honors Research Projects

For this project, we set out to create a lightweight carrying case that would be mounted to a DJI Phantom 3. This case is designed to transport small packages, such as medications, from a delivery vehicle to their final destination. Based on our maximum drone lifting capacity of 600 grams, our case, servomotor, and contents had to weigh less than or equal to that value. The coronavirus pandemic has led to an increase in contactless delivery options along with the push for immunocompromised people to avoid contact with people that may be sick. Our product would help transport necessary supplies …

Rust Preventative Spray Varnish Verification And Nozzle Development, Dakota Snyder, Collin Whitely, Stephen Patrick, William Mccullough

Williams Honors College, Honors Research Projects

This document details the research and selection of five rust preventative spray varnishes that were to be tested. These varnishes are known as the five materials. The materials underwent rust testing and in-depth analysis to see which protects against rust the best. In addition, the document reports on the construction of a prototype self-contained, automated spray varnishing unit.

Osmocean, Katie Brodersen, Alec Lanter, Maulee Sheth, Nathaniel Kiefer, Emily Bywater, Kumansh Furia, Brittany Cafferty, Hayden Schennum, Yi Xie, Abigail Werner, Deepika Ramchandani, Sandra Cordoba, Akshay Rao, Jun Chen, Abhimanyu Das, David M. Warsinger

School of Mechanical Engineering Working Papers

The objective of this Build & Test was to prove that the Osmocean wave-powered batch reverse osmosis (BRO) system is physically realizable. Through a comprehensive and systematic engineering process, the optimal components for the WEC-side Osmocean coupling were procured, assembled, and tested. The results indicate that a control effort developed for the main loop throttle valve successfully tracks input signals meant to simulate interaction with the BRO system to within 6% error. Future work will include developing a controller for the kidney loop throttle valve to assist in keeping the main loop flow rate constant as well as the direct …

Chainless Bike Drive, Dominic Apisa, Bradley Powell, Garrett Colvin, John Monsour

Williams Honors College, Honors Research Projects

The focus of this project was to design a drive system that could replace the conventional chain drive system, improving on both the efficiency and reliability, in addition to being low cost and lightweight. This report will provide background into why this group chose this as the subject of their project, as well as challenges faced throughout the design process. The design developed was a drive shaft driven by a system of pinions and gears, with a freewheel mechanism that allowed the system to coast when not pedaling. Due to cost and time constraints, only a prototype was created, with …

Feasibility Of Additive Manufacturing For Vibration Isolation Systems, Matthew Youngblood, Christian Velo, Gary Facemyer

Williams Honors College, Honors Research Projects

During transport sensitive payloads can become subject to a multitude of vibration or shock environments that can lead to damage. Using only additive manufacturing we seek to design an isolation system that can provide enough vibration and shock damping to properly protect the payload. Using modern FEA software we were able to quickly analyze a variety of solutions and determine the best one. Based on the results we have achieved through analysis, as well as pushing the manufacturing capabilities of 3D printers, we believe it is plausible to use additive manufacturing to create a fully capable vibration isolation system.

Sae Formula Team Carbon Fiber Seat, Jacob Jaksic

Williams Honors College, Honors Research Projects

roject is for the Formula SAE Zips Racing team here at the University of Akron. The team includes Jacob Jaksic, Sean Turner, Dovydas Sodys, Mike White, and Sevin Johnson. We are tasked with reducing the weight of their current seat, while remaining comfortable to the driver. Our plan was to do this with a lightweight material, specifically carbon fiber. Many different steps were required when outlining this project: finalizing a design with verification from our Zips racing advisor, completing FEA analysis on finished design, acquiring material to be molded into seat, and finding a company to fabricate out of carbon …

Foldibot The Autonomous Clothes Folder, Jacob Kittinger, Braden Glasgow, Steven Shimko

Williams Honors College, Honors Research Projects

As society becomes more technologically advanced, so does the demand for innovative products that save time; products like the Roomba have revolutionized household chores. Our teams’ vision was to develop a solution for another time-consuming household chore: folding laundry. The goal of this project was to conceptually design a marketable “robot” capable of autonomously folding clothes and explore a potential design by prototyping and testing it. Our team utilized our culmination of knowledge acquired over five years of engineering studies to turn a “pen and paper” sketch into a functioning prototype; this project used engineering tools such as a Weighted …

Design And Optimization Strategy For Ejectors Applied In Refrigeration Cycles, Riley Barta, Parveen Dhillon, James Braun, Davide Ziviani, Eckhard A. Groll

School of Mechanical Engineering Faculty Publications

Implementation of an ejector for expansion work recovery in transcritical Carbon Dioxide (CO2) cycles provides an opportunity to improve the efficiency of these environmentally-friendly refrigeration systems. However, literature outlining an approach to ejector design for a given application is lacking. This paper presents a tool to design a complete ejector applied in a vapor compression cycle. In this work, the developed design tool was validated using experimentally-derived polynomials at air conditioning conditions, then efficiencies were input to broaden the analysis to study a transcritical CO2 system with an ejector operating in the evaporating temperature range of −15 °C to 20 …

Pulse Reverse Current Electrodeposited Tio2 Doped Ni-W Coating, Sydney Hughes

Williams Honors College, Honors Research Projects

Nickel-Tungsten (Ni-W) coatings via the pulse reverse current method have been under development as a potential replacement for typical Chromium/Cadmium coatings. To increase the effectiveness of Ni-W as a coating, dopants have been tested to decrease microcracks and pores and increase overall tribological performance. Previous research by Timken Engineered Surfaces Laboratory showed that Ni-W doped with TiO₂ nanoparticles had a positive effect on coating performance. The purpose of this study was to determine the ideal solution parameters (i.e. TiO₂ concentration, pH) to maximize the benefit of the dopant when samples are subjected to tribological testing. Here, solutions of …

Door Barricade, Alex Cerino

Williams Honors College, Honors Research Projects

My senior capstone project will be a door barricade. The main idea for the use of the door barricade is for schools in the case of an intruder. The barricade that I will be designing is a solution to the inefficient barricades that I saw at my high school. It could also be used at businesses and homes. My design would be easy to use and have a fail-safe option. The two areas of mechanical engineering technology that my capstone project will focus on are stress analysis and electronics. Every part for my door barricade is drawn in SolidWorks. All …