Mechanical Engineering Commons^™

Pipe5 Finite Element Analysis For Buried Structures, David Aldous

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

PIPE5 is a finite element analysis (FEA) program designed to analyze buried pipes and culverts whose development was spearheaded by A. P. Moser. PIPE5 started as a modification of the program SSTIPN in 1981 so that the program could run in batch mode on a mainframe and was written in Fortran IV language. Various students made modifications to the original code making it compatible with personal computers and adding additional features. For more history on early PIPE5 developments see Moser [1]. In 2003 Mr. Merrill began a project of updating PIPE5. Mariner did extensive work on making the code compatible …

Solar 2007: Renewable Energy Disaster Relief Fund Gives A Helping Hand, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

In a disaster, support and utility services are damaged or destroyed leaving people without electricity, water, sanitation, and communication. Thousands of people from emergency management agencies and volunteer organizations are deployed to help after a disaster to provide life support and basic services. In this response effort, energy resources and services are lacking, making recovery efforts difficult in our high-tech world. In response to this problem, the National Energy Foundation and the Florida Solar Energy Center have formed the Renewable Energy Disaster Relief Fund (REDRF).

REDRF will collect donations from the general public, businesses, and various organizations through a variety …

Measurements And Modeling Of Coal Ash Deposition In An Entrained-Flow Reactor, Ryan P. Blanchard

Theses and Dissertations

Coal plays a significant role in meeting the world's need for energy and will continue to do so for many years to come. Economic, environmental, and public opinion are requiring coal derived energy to be cleaner and operate in a more narrow window of operating conditions. Fouling and slagging of heat transfer surfaces continues to be a challenge for maintaining boiler availability and expanding the use of available fuels and operating conditions. The work incorporates existing information in the literature on ash deposition into a User-Defined Function (UDF) for a commercial comprehensive combustion and CFD code. Results from the new …

Parametric Optimization Design System For A Fluid Domain Assembly, Matthew Jackson Fisher

Theses and Dissertations

Automated solid modeling, integrated with computational fluid dynamics (CFD) and optimization of a 3D jet turbine engine has never been accomplished. This is due mainly to the computational power required, and the lack of associative parametric modeling tools and techniques necessary to adjust and optimize the design. As an example, the fluid domain of a simple household fan with three blades may contain 500,000 elements per blade passage. Therefore, a complete turbine engine that includes many stages, with sets of thirty or more blades each, will have hundreds of millions of elements. The fluid domains associated with each blade creates …

Development Of A Miniature Vtol Tail-Sitter Unmanned Aerial Vehicle, Jeffrey V. Hogge

Theses and Dissertations

The design, analysis, construction and flight testing of a miniature Vertical Take-Off and Landing (VTOL) tail-sitter Unmanned Aerial Vehicle (UAV) prototype is presented in detail. Classic aircraft design methods were combined with numerical analysis to estimate the aircraft performance and flight characteristics. The numerical analysis employed a propeller blade-element theory coupled with momentum equations to predict the influence of a propeller slipstream on the freestream flow field, then the aircraft was analyzed using 3-D vortex lifting-line theory to model finite wings immersed in the flow field. Four prototypes were designed, built, and tested and the evolution of these prototypes is …

Slip Boundary Conditions For Shear Flow Of Polymer Melts Past Atomically Flat Surfaces, Anoosheh Niavarani, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

Molecular dynamics simulations are carried out to investigate the dynamic behavior of the slip length in thin polymer films confined between atomically smooth thermal surfaces. For weak wall-fluid interactions, the shear rate dependence of the slip length acquires a distinct local minimum followed by a rapid growth at higher shear rates. With increasing fluid density, the position of the local minimum is shifted to lower shear rates. We found that the ratio of the shear viscosity to the slip length, which defines the friction coefficient at the liquid/solid interface, undergoes a transition from a nearly constant value to the power …

Exploring The Common Design Space Of Dissimilar Assembly Parameterizations For Interdisciplinary Design, Brady M. Larson

Theses and Dissertations

The use of parametric CAD models in engineering, analysis, and optimization has greatly enhanced the effectiveness and efficiency of the product development process. Parametric models provide an attractive avenue for expansive design exploration. There still exists, however, a great challenge for products requiring design input from multiple disciplines. The collaboration of engineering disciplines can be hampered by many factors including: competing design objectives, communication of design changes, the use of different design and analysis software, and different geometry definitions. These obstacles become compounded when developing products at the assembly level. The use of solid parametric assembly models is not readily …

Generating Cad Parametric Features Based On Topology Optimization Results, William R. Blattman

Theses and Dissertations

Shape optimization has become an important tool in industry to minimize weight and generate new designs. At the same time, companies are turning to CAD-centric design strategies where robust parametric CAD models are used to generate new designs and part-families of current designs, as well as the tooling and manufacturing procedures. However, due to its complexity, the optimal topology results are often discarded or recreated by hand into a CAD model. From a design stand point, the results can be improved with the use of manufacturing constraints on the shape optimization process. These constraints improve the manufacturability based on common …

Ahata Solar Energy Resort Training Program, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

The Florida Solar Energy Center/University of Central Florida developed a Solar Energy Resort Training Program at the request of Aruba Bucuti Beach Resort Association, Aruba (AHATA) in the Caribbean Islands. The Aruba Resort Association has been interested in learning about and applying renewable energy technologies to their resorts to reduce energy consumption and cost. This report describes the activities and implementation of Florida Solar Energy Center's support to the Association to assist in the consulting, education and implementation of solar energy technologies into the resort industry in the country.

Ole Miss Engineer 2008

Ole Miss Engineer

No abstract provided.

Numerical Prediction Of Primary And Secondary Flows In A Ranque-Hilsch Vortex Tube, Ronan Oliver

Masters

The primary aim of this project is to obtain a fundamental understanding of the fluid dynamics and thermodynamics of the primary and secondary flows in a Ranque-Hilsch Vortex Tube (RHVT). These flows are highly complex and are three dimensional, compressible and viscous in nature. To obtain an understanding of these, a state of the art Computational Fluid Dynamics (CFD) software package is applied for flow prediction with advanced turbulence models, and is employed to predict the primary and secondary flows in a RHVT. The models that are used include : the k-e model, the SST model by Menter, and the …

Flight Data Analysis And Simulation Of Wind Effects During Aerial Refueling, Timothy Allen Lewis

Mechanical and Aerospace Engineering Theses - Archive

This thesis presents an analysis of data obtained in an automated aerial refueling test flight conducted with a KC-135 as the tanker and a Learjet 25 as the surrogate receiver UAV. The purpose is to identify the wind induced by the tanker wake and its effect on the receiver aircraft. From the available flight data, a direct computation of the winds experienced by the tanker and receiver is carried out. The mean variation of the receiver wind is compared with the tanker wind when the receiver is at the observation and contact positions. This results in the identification of the …

Free-Edge Stresses And Progressive Cracking In Surface Coatings Of Circular Torsion Bars, Xiang-Fa Wu, Yuris A. Dzenis, Kyle W. Strabala

Department of Engineering Mechanics: Faculty Publications

This paper considers the explicit solutions of free-edge stresses near circumferential cracks in surface coatings of circular torsion bars and their application in determining the progressive cracking density in the coating layers. The problem was formulated within the framework of linear elastic fracture mechanics (LEFM). The free-edge stresses near crack tip and the shear stresses in the cross-section of the torsion bar were approached in explicit forms based on the variational principle of complementary strain energy. Criterion for progressive cracking in the coating layer was established in sense of strain energy conservation, and the crack density is thereby estimated. Effects …

Closed-Form Development Of A Family Of Higher Order Tetrahedral Elements Through The Fourth Order, Sara Elizabeth Mccaslin

Mechanical and Aerospace Engineering Dissertations - Archive

This research is concerned with the development and implementation of a family of tetrahedral elements through the fourth order. The straight-sided tetrahedral elements are developed in closed-form. This work investigates the efficiency of closed-form implementation of stiffness matrices and error estimators compared to numerical implementation. An additional objective is the compaction of closed-form source-code files which require as little storage space as possible, a more pronounced requirement at high p-levels. For the straight-sided elements through p-level 4, the stiffness matrix, equivalent nodal load vectors, and error estimators (based on nodal averaging) are developed using closed-form equations obtained through the use …

Study Of Multibody Dynamics Using Matlab, Kalyani Soman

Mechanical & Aerospace Engineering Theses & Dissertations

Research in computational dynamics has gained importance in the past few years because of the demand for analysis and simulation of various multi-body systems in the growing mechanical and aerospace industry. These multi-body systems are made of individual bodies that are interconnected via mechanical joints. Mathematically, these joints that connect the bodies can be described as constraint equations imposed upon the motions of the involved free bodies. This process will result in an equation of motion expressed in the form of a differential-algebraic equation. It is the main objective of this thesis to develop a solution algorithm that can take …

Development And Validation Of A Dynamic Model Of The Maglev Transportation System At Old Dominion University, Ajinkya V. Deodhar

Mechanical & Aerospace Engineering Theses & Dissertations

A dynamic model for the vehicle-guideway coupled with a controller is developed using dynamic modelling software, MADYMO. The fundamental characteristics of the vehicle are obtained from detailed FE analysis in NASTRAN. The vehicle is then converted into a 21-degree-of-freedom rigid body system with 12 FE magnets. A two span concrete guideway of 54 meters in length is modelled using 3D solid Hex8 elements. The air gap is modelled as a penetration of the magnets in the guideway. The PD controller aims at achieving constant penetration (i.e. the air gap) of all magnets in the guideway, throughout the simulation. This PD …

Parallel Mpi/Fortran Finite Element Symmetrical/Unsymmetrical Domain Decomposition, Siroj Tungkatara

Civil & Environmental Engineering Theses & Dissertations

MPI/FORTRAN finite element analysis software based on Domain Decomposition (DD) formulas has been developed in this work. Efficient input data storage/data communication schemes, domain partitioning, fast symbolical and numerical sparse assembly, symmetrical/unsymmetrical sparse solver and robust symmetrical/unsymmetrical iterative solvers algorithms are all incorporated into the developed code. Parallel Precondition Conjugated Gradient (PCG) and Flexible Generalized Minimum Residual (FGMRES) are developed. Efficient computational techniques used in the developed code are explained. Numerical performance and the accuracy of the developed code are conducted on acoustic examples with medium to large grid sizes. The results obtained from ODU Wilbur cluster (under parallel processing …

Process Study For The Design Of Small-Scale 2 Kelvin Refrigeration Systems, Peter N. Knudsen

Mechanical & Aerospace Engineering Theses & Dissertations

Helium refrigeration at temperatures below 4.5-Kelvin (K), but greater than 0.8-K typically employ a sub-atmospheric process utilizing a vacuum pumping system. These types of helium refrigerators are of keen interest to present and future particle physics programs utilizing super-conducting magnet or radio-frequency technology. As such, there is a need for small scale 2-K helium refrigeration systems (i.e., those that operated below the lambda temperature) in small laboratories and test facilities at this time. This study establishes the key process parameter choices of flow ratio, heat-exchanger size, and supply pressure, and how they influence the overall system performance for various process …

Caffeine Model Identification For Vigilance Performance Prediction, Chun-Hui Huang

Mechanical & Aerospace Engineering Theses & Dissertations

The pharmacodynamics and pharmacokinetics of caffeine have been well characterized. In this study, a caffeine dynamic model is developed to describe its pharmacodynamic effects on vigilance performance. Validated biomathematical models developed to address both individual and group fatigue and alertness in a non-laboratory setting represent a tremendous commercial opportunity. First, a test data set with caffeine effects isolated from circadian and homeostatic effects is created. Then a modeling approach for input and output effects is developed and different model structures for the caffeine effects are considered. Observer/Kalman filter Identification (OKID) algorithm is proposed and developed to identify the caffeine model …

Disassembly Planning And Costing Through Petri Net Approach, Chunhsi Lei

Mechanical & Aerospace Engineering Theses & Dissertations

In the current consumer oriented environment, many new products appear in the market almost on a daily basis. Lured by advertisements and tempted by new product features, customers are constantly purchasing newer products. Acquiring newer products for often leads to throwing out older ones, but it is a totally different story for manufacturers. They need to consider the best way to reuse a product both for economic purposes and for environmental protection. Considerations for them often include: how to minimize total disassembly cost, how to achieve the lowest total disassembly time at each processing step, and how to sort valuable …

The Effect Of Hans Device On Brain Pressure Values In Finite Element Brain Models, Mihir M. Jawale

Mechanical & Aerospace Engineering Theses & Dissertations

A parametric study of behavior of different brain material properties when exposed to a mid-high severity pulse is presented. Few studies have considered brain pressure as a parameter to study the effect of change of brain material properties. Specifically pressure and strain values in the frontal and posterior fossa and occipital region of the brain are investigated for mid-high severity pulse.

The brain model is composed of several parts modeled as hexahedral elements and with different material properties. A parametric study of several material types of brain is conducted using MAthematical DYnamic MOdel (MADYMO). Initially only the finite element (FE) …