Mechanical Engineering Commons^™

Experimental And Numerical Investigation Of The Mechanism Of Blast Wave Transmission Through A Surrogate Head, Yi Hua, Praveen Akula, Linxia Gu, Jeff Berg, Carl A. Nelson

Mechanical & Materials Engineering Faculty Publications

This work is to develop an experiment-validated numerical model to elucidate the wave transmission mechanisms through a surrogate head under blast loading. Repeated shock tube tests were conducted on a surrogate head, i.e., water-filled polycarbonate shell. Surface strain on the skull simulant and pressure inside the brain simulant were recorded at multiple locations. A numerical model was developed to capture the shock wave propagation within the shock tube and the fluid-structure interaction between the shock wave and the surrogate head. The obtained numerical results were compared with the experimental measurements. The experiment-validated numerical model was then used to further ...

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 ...

Synthetic Jet Micropump, Sherif Abdou

Open Access Dissertations and Theses

The production of a novel micropump based on the synthetic jet principle is investigated both numerically and experimentally. The proposed micropump consists of a synthetic jet actuator driven by a vibrating diaphragm issuing into an inverted T- shaped channel structure forming the inlet/outlet channels of the pump.

The software package Ansys is used to perform numerical investigations of the operation of the proposed micropump. Simulations were performed to study the effect of changing the inlet/outlet channel dimensions as well as the operating frequency, amplitude and duty cycle of the excitation signal. Inlet/outlet channel widths ranging from 200 ...

Characterizing Phantom Arteries With Multi-Channel Laser Ultrasonics And Photo-Acoustics, Jami L. Johnson, Kasper Van Wijk, Michelle Sabick

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Multi-channel photo-acoustic and laser ultrasonic waves are used to sense the characteristics of proxies for healthy and diseased vessels. The acquisition system is non-contacting and non-invasive with a pulsed laser source and a laser vibrometer detector. As the wave signatures of our targets are typically low in amplitude, we exploit multi-channel acquisition and processing techniques. These are commonly used in seismology to improve the signal-to-noise ratio of data. We identify vessel proxies with a diameter on the order of 1 mm, at a depth of 18 mm. Variations in scattered and photo-acoustic signatures are related to differences in vessel wall ...

Wooden Bikes Present Capstone Challenge For Engineering Students, Jenni Hodges

News Releases

Four Cedarville seniors are building and testing wooden bicycles for a capstone engineering project. Team leader Jake Miller said the project offers a unique opportunity for students to connect their interests in engineering, woodworking and cycling.

The Penn Haptic Texture Toolkit For Modeling, Rendering, And Evaluating Haptic Virtual Textures, Heather Culbertson, Juan Jose Lopez Delgado, Katherine J. Kuchenbecker

Departmental Papers (MEAM)

The Penn Haptic Texture Toolkit (HaTT) is a collection of 100 haptic texture and friction models, the recorded data from which the models were made, images of the textures, and the code and methods necessary to render these textures using an impedance-type haptic device such as a SensAble Phantom Omni. This toolkit was developed to provide haptics researchers with a method by which to compare and validate their texture modeling and rendering methods. The included rendering code has the additional benefit of allowing others, both researchers and designers, to incorporate our textures into their virtual environments, which will lead to ...

Hvac Chapter 1, Dr Alireza Zolfaghari

Dr Alireza Zolfaghari

No abstract provided.

Non-Oxidative And Oxidative Torrefaction Characterization And, Wei-Hsin Chen

Wei-Hsin Chen

No abstract provided.

Using “Expert Employees” To Identify Duties And Tasks For Cadd Technicians In North Central Idaho: Lessons Learned From A Modified Dacum Process, Raymond A. Dixon Ph.D., Linda S. Stricklin Ph.D.

Online Journal for Workforce Education and Development

Objective: We conducted a job analysis to identify the competency profile of an entry level CADD technician in North central Idaho. Background: In 2011, the Clearwater Economic Development Association and NIMA collaborated with Lewis-Clark State College and the University of Idaho in a project to strengthen the capacity of Career and Technology Education (CTE) teachers to teach computer aided drafting and designing (CADD). An application to the National Science Foundation, Advanced Technology Education (NSF ATE) program was made and funding began July of 2011. Method: A modified DACUM was used. A total of seven expert workers from six companies ...

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 ...

Polarization Phenomena Of Hydrogen-Rich Gas In High-Permeance Pd And Pd–Cu Membrane Tubes, Wei-Hsin Chen

Wei-Hsin Chen

No abstract provided.

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 ...

Mechanics Of Regular, Chiral And Hierarchical Honeycombs, Babak Haghpanah Jahromi

Mechanical Engineering Dissertations

Approaches to obtain analytical closed-form expressions for the macroscopic elastic, plastic collapse, and buckling response of various two-dimensional cellular structures are presented. First, we will provide analytical models to estimate the effective elastic modulus and Poisson's ratio of hierarchical honeycombs using the concepts of mechanics of materials and compare the analytical results with finite element simulations and experiments.

For plastic collapse, we present a numerical minimization procedure to determine the macroscopic 'plastic collapse strength' of a tessellated cellular structure under a general stress state. The method is illustrated with sample cellular structures of regular and hierarchical honeycombs. Based on ...

Developing An Integrated Computational Environment For The Detailed Design Of A Mixing Impeller, Benjamin M. Sloan, Sunil Suram, Kenneth M. Bryden

Ames Laboratory Conference Papers, Posters, and Presentations

Digital manufacturing significantly reduces the expense and time required to produce custom products. Utilizing this technology, a customized product can be quickly manufactured. But the timescale and expense of the engineering design workflows used to develop these customized products have not been adapted from the workflows used in mass production due to the development of high fidelity models. But with digital manufacturing the economies of scale are eliminated such that producing many unique designs or many of the same designs result in the same manufacturing cost. Developing a design workflow that utilizes the developed and validated high fidelity models of ...

An Analysis Of Energy Resources Utilization For Two Metal Joining Manufacturing Processes, Jonathan Gasser

Theses and Dissertations--Mechanical Engineering

Sustainable manufacturing involves utilizing energy resources efficiently. Currently, the state of sustainability for a given manufacturing process is described by most in a qualitative sense as opposed to using quantitative metrics. This thesis offers a segment of analysis needed to understand the state of sustainability in the context of energy resource utilization. This was accomplished by measuring the order of magnitude difference between the energy consumption of a manufacturing process vs. the theoretical minimum amount of energy required to complete the same task (aluminum T-joint bond). This analysis was completed for a TIG welding process and a controlled atmosphere brazing ...

Modelling Of Radiative Heat Transfer In A Cfb Furnace By Correlation Based Zone Method, Kari Myöhänen, Mohammad Hadi Bordbar

Kari Myöhänen

No abstract provided.