Mechanical Engineering Commons^™

Flow Accelerated Corrosion In Single And Dual S-Shape Bends Under Single And Two Phase Annular Flow Conditions, Hazem Mohamed Mohamed Ahmed Mazhar

Open Access Dissertations and Theses

Flow Accelerated Corrosion (FAC) is defined as a flow enhanced mass transfer phenomenon that results in pipe wall thinning of the piping system and results in abrupt failure in some cases. FAC is controlled by the transport of corrosion species from the wall to the bulk fluid and is determined by the local distribution of the mass transfer coefficient. The overall objective of this research is to investigate the mass transfer in pipe bends arranged in single and dual S- shape configurations under single and annular two phase flow conditions. A novel wall dissolving mass transfer technique was developed to ...

Six Degree-Of-Freedom, Musculotendon Joint Stiffness: Examples With The Knee, Joshua G. A. Cashaback

Open Access Dissertations and Theses

Increased muscle stiffness helps prevent excessive movement that can lead to ligament and soft-tissue damage. There is empirical evidence suggesting that muscles are important in preventing injuries caused by excessive translational movements. Very little is known, however, on how our muscles provide translational stiffness. This thesis uses complementary theoretical (Chapters 2 and 3) and experimental (Chapter 4) techniques to address how muscles provide translational joint stiffness.

In Chapters 2 and 3, we used an elastic energy approach to successfully derive equations that quantify muscular contributions to joint stiffness. From the equations, we were able to determine how the geometric orientation ...

Experimental Convective Heat Transfer In Entrance Portion Of Rib Roughened Channels, Gidley E. Dorlus

Mechanical Engineering Master's Theses

Leading edge cooling of turbine blades is essential in the advancement of the turbine industry. There are many different methods of blade cooling, from jet impingement to film cooling to convective cooling. The present experimental investigation presented delves into the use of convective cooling along with rib-roughened walls using the steady state liquid crystal technique. There were four test sections used for this investigation, using ribs at a 45° angle on the side wall and a 90° angle on the nose portion of the test section, both relative to the incoming flow. Within each test section, 2 or 3 different ...

Exploration Of Hot Switching Damage And Damage Mechanisms In Mems Switch Contacts, Ryan Patrick Hennessy

Mechanical Engineering Dissertations

Ohmic contact, or contact-­type, Microelectromechanical Systems (MEMS) switches employ two separable metal electrodes as a contact. In the switch environment, the switch contact may experience either of two switching modes. Cold switching refers to the application of an electrical signal across the switch only when the contact is fully closed. On the other hand, hot switching refers to the application of a signal while the switch is being opened and closed. Compared to cold switching, hot switching leads to shorter contact lifetimes.

This work explores the effect of multi-­domain coupling on the behavior of an electrical contact, what ...

Design, Prototyping And Bench Testing For Biomedical Devices, Yu Pu

Mechanical Engineering Master's Theses

Bench testing for different torque based devices have different specific requirements, such as load and position requirements. Also, bench testing is very important for torque based devices before they go to real application. Therefore, bench design for new torque sensing product devices is crucial.

Three projects are included in this thesis. The first is the design and bench test for Customized Sensors for Humans Using an Integrated Polymer (C-SHIP). The second is the design and bench test for Patient Customized Ankle Foot Orthotics using Rapid Prototyping. The last is design a testbed for Gear Bearing Drives (GBD).

First, the design ...

Experimental Heat Transfer Coefficients And Friction Factors In A Rib-Roughened Leading-Edge Cooling Cavity Of A Gas Turbine Airfoil, Peter Jacob Hagan

Mechanical Engineering Master's Theses

A gas turbine airfoil contains multiple coolant passageways. These passages usually have rib roughened wall surfaces in order to increase the heat transfer from the blade to the cooling air. Auxiliary power and compressed air is very valuable in a gas turbine, therefore low pumping power requirements are crucial. The thermal performance of three different coolant channel geometries with three different rib sizes was investigated. Heat transfer calculations were performed for Reynolds numbers ranging from 6,000 to 40,000. The performance characteristics were calculated through the use of the convective heat transfer coefficient and the friction factor. In this ...

Active Vibration Control Of A Flexible Plate System, Charles Sidoti

Mechanical Engineering Master's Theses

Vibration control and/or attenuation can significantly improve the performance and operation of systems and machines in various industries. As technology advances, the methods of vibration control also become more involved and therefore allow for control of more complex structures. This thesis focuses on vibration control of a flexible plate system. The basic modeling of the physical system is developed as a precursor to the controller design. Linear controllers are explored along with advanced controllers. These controllers require an accurate model of the physical system of interest. For this reason, an experimental setup is designed and developed for implementation. A ...

Nd-Fe-B Nanoparticles Through Surfactant Assisted Mechanical Milling And Alloy Design, Jordann M. Bornhoft

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

Surfactant-assisted mechanical milling has been used to produce discrete nanoparticles of both Nd-Fe-B and Sm-Co amenable for bottom-up production of nanostructured or nanocomposite permanent magnets. However, in Nd-Fe-B the comminution of the material proceeds by transgranular fracture, which influences both the morphology of the nanoparticles and the magnetic properties. This paper utilizes alloy design to alter the fracture behavior from transgranular fracture to intergranular fracture. Nd-rich Nd₂Fe₁₄B alloys were produced by melt spinning in an overquenched state. The melt spun ribbons were annealed at 700°C and 800°C to ensure complete crystallization and to form ...

Effects Of Time Varying Background Noise Conditions On Human Perception And Performance, Andrew H. Hathaway

Architectural Engineering -- Dissertations and Student Research

This thesis was designed to study the effects of changing noise conditions on human perception and performance. In two phases, participants were exposed to a number of noise conditions and their performance on an arithmetic task involving short-term memory was monitored and their subjective perception of noise conditions was collected via questionnaires.

In the first phase, participants were tested while being subjected to RC-29(H) and RC-47(RV) conditions created by broadband noise fluctuating on different time intervals, resembling the changing noise conditions potentially found in modern HVAC systems. These intervals varied from two minutes to ten minutes. Results show ...

Near-Infrared Surface-Enhanced Fluorescence Using Silver Nanoparticles In Solution, Michael D. Furtaw

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

Fluorescence spectroscopy is a widely used detection technology in many research and clinical assays. Further improvement to assay sensitivity may enable earlier diagnosis of disease, novel biomarker discovery, and ultimately, improved outcomes of clinical care along with reduction in costs. Near-infrared, surface-enhanced fluorescence (NIR-SEF) is a promising approach to improve assay sensitivity via simultaneous increase in signal with a reduction in background. This dissertation describes research conducted with the overall goal to determine the extent to which fluorescence in solution may be enhanced by altering specific variables involved in the formation of plasmonactive nanostructures of dye-labeled protein and silver nanoparticles ...

Structural & Magnetic Characterization Study Of Hfco7 Alloy With Substitutions Of Si, Ti, Fe, Mn & B, Jacob A. Lewis

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

Magnetic materials are a critical component of the modern technological society. The market of high-energy product hard magnets is dominated by the rare-earth element containing neodymium-iron-boron (NdFeB) magnets. As a result of worldwide demand coupled with trade restrictions on rare-earth minerals, new magnet compositions are explored to reduce pressure on the already strained market. The hafnium-cobalt alloy system has shown promise as a candidate for filling the gap in saturation magnetization between rare-earth containing alloys and those made with abundant elements. This study explores the magnetic effects of silicon, titanium, iron, manganese and boron substitutions in the hafnium-cobalt-7 (1:7 ...

Ultrasounic Propagation And Scattering In Pearlitic Steel, Hualong Du

Engineering Mechanics Dissertations & Theses

Diffuse ultrasonic backscatter measurements have been especially useful for extracting microstructural information and for improving flaw detection in materials. In this dissertation, this approach is applied to inspection of railroad wheels. To improve the wear resistance, the tread surfaces of railroad wheels are usually quenched with water to increase the hardness. The pearlite phase of iron, characterized by alternating ferrite and cementite phases, is created by the quenching and the lamellar spacing within grains increases progressively from the quenched tread surface to deeper locations due to the non-uniform cooling rate. The quench depth is an important parameter governing the wheel ...

Experimental Study On The Effect Of Air Flow On Soap Bubble Formation, John M. Davidson

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

Soap bubbles are a common interfacial fluid dynamics phenomenon having applications such as buoyant hollow spherical fillers and flow visualization of large scale airflows. In contrast to the dynamics of liquid drops in gas and gas bubbles in liquid, the dynamics of soap bubbles has not been well documented, possibly because soap bubbles have gas-liquid-gas interfaces. Having the thin-liquid-film interface seems to alter the characteristics of the bubble/drop creation process. Thus, the main objective of this study is to experimentally examine how airflow develops and interacts with the soap liquid film as the film stretches and finally collapses to ...

Subway Rail Car Filter Sampling Tool, Brian Hong, Julia Pollard, Philip Ybarra

Mechanical Engineering

The following design report has been prepared by Team Slice for both Cal Poly’s Mechanical Engineering Department and Lawrence Livermore National Laboratory. This report provides an overview of the design ideation process of creating a subway rail car filter sampling tool. This cutting tool will take samples of HVAC filters from subway railcars in New York City, NY. These samples will then be used for processing in biological terror emergency response situations. This device will provide an easy, safe, and user friendly tool to cut filter samples. The current method of cutting is a pair of scissors or shears ...

Orthogonal Decomposition As A Design Tool: With Application To A Mixing Impeller, Benjamin M. Sloan

Benjamin M. Sloan

No abstract provided.

A Proposed Learner-Centered Mechatronics Engineering Instructional Program, Patrick Currier, Richard Goff, Janis Terpenny

Department of Mechanical Engineering - Daytona Beach

This paper examines the need and requirements for a mechatronics degree program. The results of a survey of the few existing programs in this field are provided. Then, using a case study example for Virginia Tech, a proposed mechatronics curriculum based on a learner-centered paradigm is described. The curriculum combines existing courses in mechanical, electrical, and computer engineering with new, hands-on courses to provide students with a chance to practice and explore the subject matter in ways consistent with the demands of both industry and accreditation. This program, if implemented, could provide a university with a unique offering to attract ...

Design And Implementation Of Eight-Legged Robotic Transporter, Jeremy David Depangher

Master's Theses and Project Reports

This thesis contains the design, manufacturing, and testing of a functional eight-legged robotic transporter based on the concept design laid out in U.S. Patent 7,246,671. The device is intended to achieve three different sequences of motion: regular driving, obstacle climbing, and stair climbing. The prototype was carried through concept design, analysis, selection of materials and components, manufacturing, software development, and final assembly and testing. The device can be assembled under multiple configurations, which harbor certain advantages and disadvantages. The results of the testing encourage the continuation of a second iteration of this concept.

Robotic Fingerspelling Hand For The Deaf-Blind, Jerry Vin

Master's Theses and Project Reports

Because communication has always been difficult for people who are deaf-blind, The Smith-Kettlewell Eye Research Institute (SKERI), in conjunction with the California Polytechnic State University Mechanical Engineering department, has commissioned the design, construction, testing, and programming of a robotic hand capable of performing basic fingerspelling to help bridge the communication gap. The hand parts were modeled using SolidWorks and fabricated using an Objet rapid prototyper. Its fingers are actuated by 11 Maxon motors, and its wrist is actuated by 2 Hitec servo motors. The motors are controlled by Texas Instruments L293D motor driver chips, ATtiny2313 slave microcontroller chips programmed to ...

Visualizing Mechanics: Improving Student Learning Through Video Demonstrations, Blake A. Wetherton, Olumide A. Awofeso, Carolyn E. Creighton, Adam F. Potrzebowski, Charles M. Krousgrill, Jeffrey F. Rhoads

The Summer Undergraduate Research Fellowship (SURF) Symposium

The Purdue Mechanics Freeform Classroom (PMFC) is a project that seeks to reform engineering mechanics education by integrating content and technology; enhancing communication between students, their peers, and instructors; accommodating a broader range of learning styles; and facilitating greater depths of understanding. In an attempt to increase the PMFC’s efficacy, a series of demonstration videos has been produced. As demonstrated by the popularity and pervasiveness of websites such as YouTube, short videos have the potential to captivate audiences. As such, these videos have incredible promise in educational contexts. In the PMFC series of videos, entitled Visualizing Mechanics, each imitates ...

Active Dense Tensegrity Structure: A Novel Concept For Shape Morphing Structures, Zhiwei Wu, Thomas Siegmund

The Summer Undergraduate Research Fellowship (SURF) Symposium

Shape morphing is of relevance for advanced engineering systems such as future aerospace vehicles. Tensegrity structures, a structure comprised of a set of discontinuous compressed struts held together with a continuous web of tensioned cables, can function as the foundation of a shape morphing system (Keith et al, 2007). However, the classic tensegrity structures may not be ideal in all configurations because the space within the structure is not utilized. As an alternative, the present work proposes a dense tensegrity system as an assembly of cables carrying tensions only and polyhedral elements under compression only. An active dense tensegrity can ...