Mechanical Engineering Commons^™

Numerical Methods For Simulating Multiphase Electrohydrodynamic Flows With Application To Liquid Fuel Injection, Bret Van Poppel

West Point ETD

One approach to small-scale fuel injection is to capitalize upon the benefits of electrohydrodynamics (EHD) and enhance fuel atomization. There are many potential advantages to EHD aided atomization for combustion, such as smaller droplets, wider spray cone, and the ability to control and tune the spray for improved performance. Electrohydrodynamic flows and sprays have drawn increasing interest in recent years, yet key questions regarding the complex interactions among electrostatic charge, electric fields, and the dynamics of atomizing liquids remain unanswered. The complex, multi-physics and multi-scale nature of EHD atomization processes limits both experimental and computational explorations.

In this work, novel, …

Piezoresistive Nano-Composites: Characterization And Applications, Thomas B. Hyatt

Theses and Dissertations

Innovative multifunctional materials are essential to many new sensor applications. Piezoresistive nano-composites make up a promising class of such materials that have the potential to provide a measurable response to strain over a much wider range than typical strain gages. Commercial strain gages are currently dominated by metallic sensors with a useable range of a few percent strain at most. There are, however, many applications that would benefit from a reliable wide-range sensor. These might include the study of explosive behavior, instrumentation of flexible components, motion detection for compliant mechanisms and hinges, human-technology interfaces, and a wide variety of bio-mechanical …

Prediction Of The Transport Properties Of A Polyatomic Gas, Zhi Liang, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An Ab Initio Molecular Potential Model is Employed in This Paper to Show its Excellent Predictability for the Transport Properties of a Polyatomic Gas from Molecular Dynamics Simulations. a Quantum Mechanical Treatment of Molecular Vibrational Energies is Included in the Green and Kubo Integral Formulas for the Calculation of the Thermal Conductivity by the Metropolis Monte Carlo Method. using CO2 Gas as an Example, the Fluid Transport Properties in the Temperature Range of 300-1000 K Are Calculated Without using Any Experimental Data. the Accuracy of the Calculated Transport Properties is Significantly Improved by the Present Model, Especially for the Thermal …

Intelligibility Of Electrolarynx Speech Using A Novel Actuator, Brian Madden, Mark Nolan, Ted Burke, James Condron, Eugene Coyle

Conference Papers

During voiced speech, the larynx provides quasi-periodic acoustic excitation of the vocal tract. Following a laryngectomy, some people speak using an electrolarynx which replaces the excitatory function of the absent larynx. Drawbacks of conventional electrolarynx designs include the buzzing monotonic sound emitted, the need for a free hand to operate the device, and difficulty experienced by many laryngectomees in adapting to its use. Despite these shortcomings, it remains the preferred method of speech rehabilitation for a substantial minority of laryngectomees. In most electrolarynxes, mechanical vibrations are produced by a linear electromechanical actuator, the armature of which percusses against a metal …

Temperature-Dependent Photoabsorption Cross-Section Of Cyano-Diacetylene In The Vacuum Uv, N. Fray, Y. Bénilan, M.-C. Gazeau, A. Jolly, M. Schwell, E. Arzoumanian, Et. Es-Sebbar, T. Ferradaz, J.- C. Guillemin

Dr. Et-touhami Es-sebbar

Using synchrotron radiation as a tunable VUV light source, we have measured, for the first time, the absolute photoabsorption cross sections of HC5N with a spectral resolution of 0.05 nm in the region between 80 and 205 nm from 233 to 298 K. The measured cross sections are used to predict the HC5N photodestruction rate in the solar system and to model a transmission spectrum in Titan's atmosphere. Comparing the latter with that acquired by the Ultraviolet Imaging Spectrograph on board the Cassini spacecraft, we have determined an upper limit of 2.7 × 10−5 on the HC5N abundance at 1100 …

Testing The Test: Validity And Reliability Of Senior Exit Exam, Lizabeth Schlemer, Daniel Waldorf

Industrial and Manufacturing Engineering

A senior exit exam is considered an excellent direct measure of student learning for ABET assessment, but the usefulness of the information gathered is related to the validity and reliability of the test itself. The Industrial and Manufacturing Engineering Department at California Polytechnic State University, San Luis Obispo has used a content exam for several years. This paper will discuss test development, administration, and the role it plays in the assessment process. In addition, the test is evaluated using the standard psychometric techniques of reliability and validity. The results of the evaluation are used to refine the test. The importance …

Development And Implementation Of An Introduction To Stem Course For Dual-Enrollment Programs, Horacio Vasquez, Arturo Fuentes, Javier Macossay-Torres, Martin W. Knecht, Robert Freeman

Mechanical Engineering Faculty Publications and Presentations

A new Introduction to Science, Technology, Engineering, and Mathematics (STEM) course was developed and taught for the first time during the summer in 2009 to dual enrollment college students at South Texas College (STC). The new Introduction to STEM course was developed in collaboration between STEM Faculty members at the University of Texas-Pan American (UTPA) and STC, with the objective of creating, supporting and strengthening STEM pathways for students in the Dual-Enrollment Engineering Academy (DEEA) and other dual-enrollment or similar programs. The course was offered to two groups of students, at two different campuses in the DEEA program at STC. …

Analysis Of Power System Frequency Responses With Hydro Turbines Incorporating Load Shedding, Lin Gao

Lin Gao

As shown in many recent works, the load-frequency behavior can be represented by system frequency response models especially for an islanding process. In this paper, a frequency response model incorporating an under-frequency load-shedding scheme is presented for islanding power system simulations. The model was applied for a realistic power system with hydro power generators. The hydro power generator model parameters were identified and similar responses were observed between the simulations and the accident records. The simulation results showed disadvantages of the primary frequency control systems of hydro power generators at the beginning of the load disturbances. The power system stability …

Laminar Flow Past An Oscillating Circular Cylinder In Cross Flow, Pham Anh-Hung, Lee Chang-Yeol, Seo Jang-Hoon, Chun Ho-Hwan, Kim Hee-Jung, Hyun-Sik Yoon, Dong-Woo Park, Il-Ryong Park

Journal of Marine Science and Technology

The present study numerically investigates the twodimensional laminar flow past a circular cylinder forced to oscillate transverse to the free-stream. The numerical simulations are performed at a various range of cylinder oscillation frequency ranged between 0.8 and 1.2 of the natural vortex shedding frequency, and the oscillation amplitude extended up to 50% of the cylinder diameter at one Reynolds number of 185 showing the typical two-dimensional vortex shedding. The immersed boundary method is used to handle the oscillating cylinder in a rectangular grid system using the finite volume method. The primary vortex shedding frequency has the same value with the …

Heat-Balance Integral To Fractional (Half-Time) Heat Diffusion Sub-Model, Jordan Hristov

Jordan Hristov

The fractional (half-time) sub-model of the heat diffusion equation, known as Dirac-like evolution diffusion equation has been solved by the heat-balance integral method and a parabolic pro file with unspecified exponent. The fractional heat-balance integral method has been tested with two classic examples: fixed temperature and fixed flux at the boundary. The heat-balance technique allows easily the convolution integral of the fractional half-time derivative to be solved as a convolution of the time-independent approximating function. The fractional sub-model provides an artificial boundary condition at the boundary that closes the set of the equations required to express all parameters of the …

Computer Simulation Of A Biomass Gasification-Solid Oxide Fuel Cell Power System Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

The operation and performance of a solid oxide fuel cell (SOFC) stack on biomass syn-gas from a biomass gasification combined heat and power (CHP) plant is investigated. The objective of this work is to develop a model of a biomass-SOFC system capable of predicting performance under diverse operating conditions. The tubular SOFC technology is selected. The SOFC stack model, equilibrium type based on Gibbs free energy minimisation, is developed using Aspen Plus. The model performs heat and mass balances and considers ohmic, activation and concentration losses for the voltage calculation. The model is validated against data available in the literature …

Improving Clinical Access And Continuity Through Physician Panel Redesign, Hari Balasubramanian, Ritesh Banerjee, Brian Denton, James Naessens, James Stahl

Hari Balasubramanian

BACKGROUND: Population growth, an aging population and the increasing prevalence of chronic disease are projected to increase demand for primary care services in the United States. OBJECTIVE: Using systems engineering methods, to re-design physician patient panels targeting optimal access and continuity of care. DESIGN: We use computer simulation methods to design physician panels and model a practice’s appointment system and capacity to provide clinical service. Baseline data were derived from a primary care group practice of 39 physicians with over 20,000 patients at the Mayo Clinic in Rochester, MN, for the years 2004–2006. Panel design specifically took into account panel …

Natural Fibers And Fiberglass: A Technical And Economic Comparison, Justin Andrew Zsiros

Theses and Dissertations

Natural fibers have received attention in recent years because of their minimal environmental impact, reasonably good properties, and low cost. There is a wide variety of natural fibers suitable for composite applications, the most common of which is flax. Flax has advantages in tensile strength, light weight, and low cost over other natural fibers. As with other natural and synthetic fibers, flax is used to reinforce both thermoset and thermoplastic matrices. When flax is used in thermoplastic matrices, polypropylene and polyethylene are the main resins used. Although at first glance flax may seem to be a cheaper alternative to fiberglass, …

Testing Guidelines For New Product Development, Derek W. Egbert

Theses and Dissertations

While many literary sources outline the product development process, few make mention of the prototyping and testing stage. This thesis suggests that because of its importance in the product development process, "Testing" should be documented as a major step and not just listed as a side note. As part of the testing step, it is suggested that standardized, in-use, and market tests be used to properly evaluate a product. While many rely solely on standardized tests to validate their products, effective in-use tests can be another vital tool that can prove the performance of the product in more specific and …

Multi-Objective Optimization Of The Molecular Structure Of Refrigerants, Suvrat Bhargava

FIU Electronic Theses and Dissertations

The aim of this work was to develop a new methodology, which can be used to design new refrigerants that are better than the currently used refrigerants. The methodology draws some parallels with the general approach of computer aided molecular design. However, the mathematical way of representing the molecular structure of an organic compound and the use of meta models during the optimization process make it different. In essence, this approach aimed to generate molecules that conform to various property requirements that are known and specified a priori. A modified way of mathematically representing the molecular structure of an …

Steady-State Green’S Function Solution For Moving Media With Axial Conduction, A. Haji-Sheikh, J. V. Beck, Kevin D. Cole

Mechanical & Materials Engineering Faculty Publications

The objective of this presentation is the development of a generalized steady-state Green’s function solution to study the temperature field in moving bodies. This type of solution permits the inclusion of different nonhomogeneous boundary conditions, volumetric heat sources, and possible position-dependent thermophysical properties. Although the mathematical formulation is for moving solids, it can be used to study the heat transfer in a moving fluid with a non-uniform velocity distribution passing through a micro-channel or fluid-saturated porous ducts. Additionally, this presentation includes the application of this Green’s function solution to acquire numerical information for selected examples to further illustrate the numerical …

Traversing Probe Assembly, Josh Bugni, Andrew Sofranko

Mechanical Engineering

No abstract provided.

Water Conservation Device, Michael Eichermueller, Michael (Mike) Moren, Florian Liefhold, Philipp Von Vopelius, Christoph Wagner, Tommy Stendel, Jacob Venzor

Mechanical Engineering

The Water Conservation Project (WCP) is a design concept to reduce the water consumption on startup of a shower. Every time a shower is started with a conventional tank water heater, approximately 7.5 liters of cold water is flushed down the drain without being used before the hot water reaches the faucet. For a city the size of San Luis Obispo, this amounts to approximately 121 million liter of water per year. The main goal of this project was to devise a way to conserve the cold water that is contained in the hot water pipes before every shower. Ultimately, …

Design, Construction, And Evaluation Of A Direct Drive Mud Motor, Jarrett Martin

BioResource and Agricultural Engineering

This senior project discusses the design and construction of a direct drive mud motor. The motor will be mounted on the back of a flat bottom, aluminum boat. The design includes the engine, prop, and everything between. Upon completion of the project, the motor will be field tested to verify operation.

Assessing Curriculum Improvement Through Senior Projects, Jianbiao Pan, Albert Liddicoat, James G. Harris, Linda Shepherd

Industrial and Manufacturing Engineering

Senior project and/or capstone design courses are intended to provide a culminating design experience for students and to demonstrate their understanding of engineering knowledge and their ability to apply that knowledge to practical problems. It is expected that the quality and attributes of students’ senior design projects can be used as a good measure of determining how well the curriculum prepares students to engage in engineering design as well as a measure of faculty teaching and student learning. This paper reports the results of a study designed to assess whether the new computer engineering curriculum implemented at Cal Poly over …