Mechanical Engineering Commons^™

Fluid Dynamic Factors As A Cause And Effect Of Biofilm Formation Of Staphylococcus Aureus Biofilms, Erica Sherman

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Staphylococcus aureus bacteria are able to form biofilms and distinctive tower structures that facilitate their ability to tolerate treatment and to spread within the human body. The formation of towers, which break off, get carried downstream and serve to initiate biofilms in other parts of the body are of particular interest here. It is known that flow conditions play a role in the development, dispersion and propagation of biofilms. The influence of flow on tower formation and what factors lead to tower formation is not at all understood The hypothesis being examined is that tower structures form within a specific …

Sanitation System For Underdeveloped Countries, Anish Agrawal, Mutian Tang, Dylan Lesher, Reid Schur

Mechanical Engineering Design Project Class

Currently, there are over 2.5 billion people living in the world without having access to proper sanitation. This is primarily because of lack of access to water and/or their financial situation to afford a sanitation system. Therefore, there is a need for a sanitation system which can flush in less water and is inexpensive. This project involves the creation of a sanitation system for use in impoverished areas with little access to water or electricity.

Maneuverable Backpack Scooter Attachment, Andrew Goldfield, Alex Roesch, Cosmo Centanni, Nina Nepa

Mechanical Engineering Design Project Class

A mechanical device that will aid in the collaboration between a scooter and a backpack. Due to the weight of typical backpack, our device will aid the consumer to carry less weight on their backs, and create a device to fold into the scooter so that it nicely fits in a classroom setting. This device will be detachable so that the scooter can be operated without the attachment.

Automatic Onion Peeler, William R. Luer, Matthew O. Clohisy, Craig A. Claire, Dylan L. Newcomb

Mechanical Engineering Design Project Class

Our senior design report encompasses the design selection, process, and fabrication of an automatic onion peeler. Our design is intended for the peeling of medium yellow onions in restaurant-scale applications. Our machine is easily cleaned and can be safely operated by one person.

Universal Pitter, Angelica Price, Rachel Venn

Mechanical Engineering Design Project Class

Fruits with pits in them have been cumbersome to eat due to the delicate quality of the fruit and the rigid structure of the pits that must be removed. Many types of pitters already exist, but any are for small pits such as cherries and olives or involve to much manual action. This pitter will remove the pit out of multiple types of fruit while holding the fruit in a manner that does not damage the fruit. This projected was initiated by Rachel Venn, an engineering student at Washington University in St. Louis, who took a pole amongst family and …

Asme Student Design Challenge, James Mitchell, Ean Murnan, Alex Wirtz

Mechanical Engineering Design Project Class

The Olympic Summer Games test the abilities of people throughout the world in a wide variety of athletic challenges. The athlete that wins the Olympic decathlon or heptathlon is referred to as the world’s greatest male or female athlete. The 2017 Student Design Competition challenges your technical design skills to create a robot that is fast, strong, and agile. Your team must build a remotely controlled device to compete against others in five different events – a robot pentathlon. Scores from each of the events will be combined to determine the overall champion. Our team will attempt to design a …

Mems 411 Design Report Group O: Naked Mole Rat Trap, Drew Pikey, Adam Glassl, Sam Nadell

Mechanical Engineering Design Project Class

Naked mole-rats are mouse size rodents that live in underground colonies in East Africa. They are best known for having a queen and workers like bees. Prof Stan Braude has been studying them in Kenya and Ethiopia for over 25 years and has trapped over 10,000 of these animals, marked and released them. He is the world’s expert at trapping naked mole-rats and yet, he still needs a better trap. Prof. Stan Braude is looking forward to working with a team of real engineers and designers who can help him complete this project.

Autonomous Shopping Cart, John Gutsch, Steven Taschner, Asim Zaidi

Mechanical Engineering Design Project Class

In shopping centers across the United States, customers must return shopping carts after they used them by themselves. For a variety of reasons, a significant number of shopping carts are left in parking lots after being used. This results in expenses to the store in the form of damaged carts, man hours required to return each one, and law suits from customers whose cars are damaged by free carts. This project is an add-on mechanism by which allows shopping carts to return to the shopping center autonomously. The cart should be able to locate a preset track that is set …

Group H: Expandable Brush, Aaron Hall, Michael Roznik

Mechanical Engineering Design Project Class

This is an overview of our project to design an expandable brush. This brush is designed to be versatile and able to clean a variety of vessels with narrow necks, wide bases, and complex geometries. Our prototype consisted of two parts: an outer sleeve with a deflector and a handle with a head piece to hold our bristle filaments. This design allows the user to insert the brush into a vessel and then control how far outward the bristles expand for easy cleaning.

Reinventing The Dishwasher, Caryn Devaney, Carter Fraser, Aaron Walters

Mechanical Engineering Design Project Class

Most people aren’t excited to do the dishes. Still, washing cookware like pots and pans is an unavoidable task - and even those who own dishwashers typically choose to handwash them after use. After conducting a wide-ranging market survey, we designed a standalone device which can fill the existing gap between handwashing and dishwashing. We successfully built a single pan dishwasher which simulates hand washing to clean nonstick frying pans.

Building A Better Naked-Mole Rat Trap Mems 411- Senior Design Course, Alex Flammond, Lance Middleton, Andrew Chang

Mechanical Engineering Design Project Class

In this paper, we design, analyze, test, and construct an improved naked mole rat trap for Prof. Stan Braude of Washington University in St. Louis.

Telescoping Cup Holder, Richard Kristian O. Pajarillo, Eric Nehrbas, Charlie Morrow

Mechanical Engineering Design Project Class

Cup holders are a beloved feature of the modern automobile because they keep your drink stable and close, ensuring that minimal work is needed to grab it. Our mission is to provide a cup holder for everyday use outside of vehicles. Our device will hold drinks of most sizes, and will keep them cool. Motion activation will raise the drink to a convenient height using a telescoping motion, and then lower to a sturdy position that is out of the way. The finished product will minimize the amount of work required to retrieve the drink, and grab some attention as …

An Improve Naked Mole Rat Trap, Group Iii, Spencer Egly, Ted Daley, Andrew Thompson

Mechanical Engineering Design Project Class

This project attempts to improve on Dr. Stan Braude’s current Naked Mole Rat trap design. Dr. Braude currently uses his trap to catch and tag naked mole rats for his research. While Dr. Braude is happy with his current trap, he designed them himself over twenty years ago, and believes that they can be improved and modernized for increased ease and convenience. The key project goal is to deliver an improved trap to Dr. Braude that will meet his needs. The modifications that this project will attempt to deliver are a repeatable, solar powered trap that is compatible with his …

Modeling Pyrolysis Of Large Coal Particles With Many Species, Jianqing Li

Master's Theses (2009 -)

Coal currently supplies 40% of the world’s electricity needs, and is one of the most important energy sources. As the initial stage of coal combustion, pyrolysis is a thermal decomposition process which converts coal into light gases and tars, which are subsequently consumed in combustion reactions, as well as solid char. Recently there has been interest in using slow pyrolysis as a stand-alone process for the production of chemicals and fuels from large (mm-scale) coal particles. Simulations can be used to efficiently study the impact of pyrolysis conditions on gas, tar and char yields, as well as gas and tar …

Human-Like Rewards To Train A Reinforcement Learning Controller For Planar Arm Movement, Kathleen M. Jagodnik, Philip S. Thomas, Antonie J. Van Den Bogert, Michael S. Branicky, Robert F. Kirsch

Mechanical Engineering Faculty Publications

High-level spinal cord injury (SCI) in humans causes paralysis below the neck. Functional electrical stimulation (FES) technology applies electrical current to nerves and muscles to restore movement, and controllers for upper extremity FES neuroprostheses calculate stimulation patterns to produce desired arm movement. However, currently available FES controllers have yet to restore natural movements. Reinforcement learning (RL) is a reward-driven control technique; it can employ user-generated rewards, and human preferences can be used in training. To test this concept with FES, we conducted simulation experiments using computer-generated ``pseudohuman{''} rewards. Rewards with varying properties were used with an actor-critic RL controller for …

Special Issue: Selected Papers From Idetc 2015, Venkat N. Krovi, Andrew P. Murray, James Schmiedeler

Mechanical and Aerospace Engineering Faculty Publications

This second IDETC Special Issue, containing 19 papers from researchers in seven countries on three continents, seeks to cap- ture the current interest topics and latest results from the 39th ASME Mechanisms and Robotics (M&R) conference. The topics span the synthesis and analysis of novel mechanisms and robots as well as their validation in a variety of applications. The papers are organized with contributions to the core theoretical methodol- ogies of M&R (five papers) appearing first. The application areas that follow are micro air vehicles (MAVs) (two papers), modular robotics (three papers), origami applications (three papers), medi- cal robotics (three …

Effect Of Fiber Material On Ozone Removal And Carbonyl Production From Carpets, Omed A. Abbass, David J. Sailor, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Indoor air quality is affected by indoor materials such as carpets that may act as sources and/or sinks of gas-phase air pollutants. Heterogeneous reactions of ozone with carpets may result in potentially harmful products. In this study, indoor residential carpets of varying fiber types were tested to evaluate their ability to remove ozone, and to assess their role in the production of carbonyls when exposed to elevated levels of ozone. Tests were conducted with six types of new unused carpets. Two sets of experiments were conducted, the first measured ozone removal and ozone deposition velocities, and the second measured primary …

Development And Implementation Of High Fidelity Human Models For The Investigation Of Blast And Non-Penetrating Projectile Impact, Candice F. Cooper

Mechanical Engineering ETDs

Military operations abroad have highlighted the effects of several types of physical traumas including traumatic brain injury and behind armor blunt trauma. While previous approaches toward understanding and mitigating trauma caused by blast or blunt impact relied upon physical testing of animal subjects, post mortem human subjects, or human tissue surrogates, recent advances in computational capability have spurred a growing area of research in computational investigations into wound injury and its mitigation. The development of high-fidelity human torso and head-neck-torso models are presented here. These models are employed in blast and non-penetrating projectile impact simulations in order to demonstrate the …

Preface-Jes Focus Issue On Electrolysis For Increased Renewable Energy Penetration, B. Pivovar, M. Carmo, K. Ayers, X. Zhang, J. O'Brien

Mechanical & Aerospace Engineering Faculty Publications

(First paragraph) Today represents a particularly exciting time, as our planet’s energy system is undergoing major changes due to dramatically decreasing renewable energy prices and increasing societal concerns over greenhouse gas emissions, criteria pollutants (arsenic, mercury, NOx, particulate matter), and climate change. These factors are pushing society toward deep decarbonization of our energy system, perhaps the most challenging issue facing the planet today. Unfortunately, wind and solar energy, while both promising generation sources, come with intermittency challenges and have limitations in their abilities to impact industrial and transportation sector demands where fossil fuel energy carriers based on chemical bonds have …

Analysis Of Fatigue Crack Propagation In Welded Steels, Roberto Angelo Demarte

Master's Theses (2009 -)

This thesis presents the study of fatigue crack propagation in a low carbon steel (ASTM A36) and two different weld metals (AWS A5.18 and AWS A5.28). Fatigue crack propagation data for each weld wire is of interest because of its use for predicting and analyzing service failures. Fatigue crack growth test specimens were developed and fabricated for the low carbon steel base metal and for each weld wire. Weld specimens were stress relieved prior to fatigue testing. Specimens were tested on a closed-loop servo hydraulic test machine at two different load ratios. Fatigue test data was collected to characterize both …

Changing Trends In Wave Heights In The U.S. Mid-Atlantic Region, Hillary Lane

Civil & Environmental Engineering Theses & Dissertations

The pace and effects of climate change are an area of constant focus for coastal engineers as evolving patterns in the atmosphere worldwide affect the oceans and coasts on a regional and global scale. Surface waves respond to changing wind patterns both locally and from propagating swell, and the difficulty in predicting future wind patterns is well-established. Expectations that climate change will result in more frequent and intense coastal storms and consequently greater wave heights in the North Atlantic are still unrealized, and recent forecasts from a variety of atmosphere-ocean coupled global climate models instead predict decreasing wave heights through …

Parametric Investigation Of A Laboratory Drop Test To Simulate Base Acceleration Induced By Wave Impacts Of High Speed Planing Craft, John D. Barber

Mechanical & Aerospace Engineering Theses & Dissertations

High speed operations in a small craft can be physically punishing and, in some circumstances, even dangerous for the crew. The aspect of small craft operations that make them punishing for the crew is wave slamming generated by wave impacts as the craft is traveling over the seas at high speed.

The initial step of this thesis effort was to perform a literature survey to determine what knowledge existed within the technical and academic community about wave slamming and simulating them with drop tests.

Eventually, a final experiment strongly influenced by the experiment model found in (Protocol 1, 2014) was …

An Examination Of The Indentation Size Effect In Fcc Metals And Alloys From A Kinetics Based Perspective Using Nanoindentation, David Earl Stegall

Mechanical & Aerospace Engineering Theses & Dissertations

The indentation size effect (ISE) in metals is described as the rise in hardness with decreasing depth of indentation and contradicts conventional plasticity behavior. The goal of this dissertation is to further examine the fundamental dislocation mechanisms that may be contributing to the so-called indentation size effect. In this work, we examined several metals and alloys including 99.999% Aluminum (SFE ~200 mJ/m²), 99.95% Nickel (SFE ~125 mJ/m²), 99.95% Silver (SFE ~22 mJ/m²⁾, and three alloys, alpha brass 70/30 (SFE >10 mJ/m²), 70/30 nickel copper (SFE ~100 mJ/ …

Using Everyday Objects To Engage Students In Standards Education, Margaret Phillips, Paul Mcpherson

Libraries Faculty and Staff Presentations

This paper describes an innovative approach to standards education in an undergraduate mechanical engineering technology design course. The work is focused on making standards appeal to students by using “everyday objects” (e.g. toaster, ladder, grill, etc.) as catalysts to introduce the topic of standards in a way that connects to students’ daily lives. The project involves instructor-librarian collaboration to incorporate information literacy and campus library resources into the standards curricula, so that students not only become familiar with standards resources, but also proficient at searching for and locating the documents. Preliminary results and observations indicate this is an effective approach …

Thermal Analysis Of Continuous And Patterned Multilayer Films In The Presence Of A Nanoscale Hot Spot, Jia-Yang Juang, Jinglin Zheng

Department of Mechanical and Materials Engineering: Faculty Publications

Thermal responses of multilayer films play essential roles in state-of-the-art electronic systems, such as photo/micro-electronic devices, data storage systems, and silicon-on-insulator transistors. In this paper, we focus on the thermal aspects of multilayer films in the presence of a nanoscale hot spot induced by near field laser heating. The problem is set up in the scenario of heat assisted magnetic recording (HAMR), the next-generation technology to overcome the data storage density limit imposed by superparamagnetism. We characterized thermal responses of both continuous and patterned multilayer media films using transient thermal modeling. We observed that material configurations, in particular, the thermal …

Inverse Structure Functions In The Canonical Wind Turbine Array Boundary Layer, Bianca Viggiano, Moira Gion, Naseem Ali, Murat Tutkun, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Wind tunnel measurements for a 3×3 canonical wind turbine array boundary layer are obtained using hot-wire anemometer velocity signals. Two downstream locations are considered, referring to the near- and far-wake, and 21 vertical points are acquired per profile. Velocity increments and exit distances are used to quantify inverse structure functions at both downstream locations. Inverse structure functions in the near-wake show a similar profile for the main vertical locations, but diverge as the moment is increased. In the far-wake, inverse structure functions converge toward a single function for all vertical location and moments. The scaling exponents for inverse structure functions …

A Comparison Of Specularly Reflective Boundary Conditions And Rotationally Invariant Formulations For Discrete Ordinate Methods In Axisymmetric Geometries, Jian Cai, Somesh Roy, Michael F. Modest

Mechanical Engineering Faculty Research and Publications

In simulations of periodic or symmetric geometries, computational domains are reduced by imaginary boundaries that exploit the symmetry conditions. Two boundary conditions are proposed for Discrete Ordinate Methods to solve axisymmetric radiation problems. Firstly, a specularly reflective boundary condition similar to that is used in Photon Monte Carlo methods is developed for Discrete Ordinate Methods. Secondly, the rotational invariant formulation is revisited for axisymmetric wedge geometries. Correspondingly, a new rotationally invariant boundary condition specially designed for axisymmetric problems on wedge shape is proposed to enforce the rotational invariance properties possessed by the radiative transfer equation (RTE) but violated by three-dimensional …

On Phase Change Material Heat Exchangers: A Computational And Experimental Investigation, Christian Omar Rodriguez Dieppa

Theses and Dissertations

The emergence of ground- and airborne-based high energy laser (HEL) weapon systems has created a need for high-rate thermal energy storage (TES) devices that meet demanding size, weight, and power (SWaP) requirements for integration into the HEL thermal management system (TMS). Current and near-term HEL weapon systems produce thermal loads on the order of 30-300 kW when emitting, and approximately 5-10% of the peak load when in a non-emitting standby state. Emission to standby duty cycles of 10-50% are common, and therefore, sizing the TMS for real-time rejection of the peak thermal load is not practical. Accordingly, TES components can …

Polynomial Chaos For The Computation Of Annual Energy Production In Wind Farm Layout Optimization, Santiago Padrón, Andrew P.J. Stanley, Jared Thomas, Juan Alonso, Andrew Ning

Faculty Publications

Careful management of wake interference is essential to further improve Annual Energy Production (AEP) of wind farms. Wake effects can be minimized through optimization of turbine layout, wind farm control, and turbine design. Realistic wind farm optimization is challenging because it has numerous design degrees of freedom and must account for the stochastic nature of wind. In this paper we provide a framework for calculating AEP for any relevant uncertain (stochastic) variable of interest. We use Polynomial Chaos (PC) to efficiently quantify the effect of the stochastic variables—wind direction and wind speed—on the statistical outputs of interest (AEP) for wind …

Four-Wheel Steering, Theodore Wisniewski, Andrew Sparrow, Phil Rowsell

Mechanical Engineering Design Project Class

This prototype Four-Wheel Steering system is designed for a Formula SAE racecar. Multiple steering geometries can be applied to optimize the handling across a range of speeds. Ackermann steering geometry at low speeds improves the car’s agility in tight, technical race courses. At high speeds the steering transitions to parallel steering geometry, improving stability and giving the driver more precise control over the vehicle. The system fits seamlessly within the rear suspension packaging of the existing WashU Racing vehicle design and minimizes addition of weight by using compact and lightweight electronic linear actuators to steer the rear wheels. In testing …