Engineering Science and Materials Commons^™

Numerical Simulation Of Separating Flows Using Computational Models Based On The Vorticity Confinement Method, Lesong Wang

Doctoral Dissertations

The objective of the present research is to investigate the recent development of the vorticity confinement method. First, a new formulation of the vorticity confinement term is studied. Advantages of the new formulation over the original one include the ability to conserve the momentum, and the ability to preserve the centroid motion of some flow properties such as the vorticity magnitude. Next, new difference schemes, which are simpler and more efficient than the old schemes, are discussed. At last, two computational models based on the vorticity confinement method are investigated. One of the models is devised to simulate inviscid flows …

Directional Solidification, Microstructures And Mechanical Properties Of Cr-Cr3si Eutectic Alloys, Hongbin Bei

Doctoral Dissertations

Alloys based on intermetallics have been considered for high temperature structural applications. However, many of these alloys suffer from intrinsic brittleness and low fracture toughness at ambient temperature. Therefore, ductile-phase-toughened intermetallic composites are being investigated as a means to improve the fracture toughness. A subset of this class of materials is in-situ composites produced by directional solidification of intermetallic eutectics. In this study, the Cr-Cr₃Si eutectic system is selected as a model system to investigate composites by directional solidification, where the strong, but brittle Cr₃Si is combined with a more ductile Cr-rich solid solution.

A series …

Effect Of Loading Frequency On Intervertebral Disc Cells., Kristen Nicole Loveless

Masters Theses

Cells of the intervertebral disc have a limited capacity for matrix repair and may contribute to the onset and progression of degenerative disc changes. Disc degeneration contributes to declining nutrition, loss of viable cells, cell senescence, post-translational modification of matrix proteins, accumulation of degraded matrix molecules, and fatigue failure of the matrix. During daily activities intervertebral discs are exposed to oscillatory hydrostatic loads. It is known that dynamic loads with critical frequencies close to that of the human spine resonant frequency (4-8 Hz) have a destructive effect on disc tissue properties. Whether this destructive effect is purely mechanical due to …

Modeling Of Circulation Zone And Shear Layers In Coaxial Injectors, Clayton Andrew White

Masters Theses

Gaseous/gaseous hydrogen oxygen shear coaxial injectors were modeled to investigate grid parameters affecting solution and to determine if a steady state solution might exist if only one circulation zone was present. The General Equation Mesh Solver (GEMS), which implements the Reynolds Averaged Navier-Stokes equations with the k-ω turbulence model, was used to conduct the study. The Gambit grid generator was used to construct computational grids. Different grids were compared in a search for the optimum configuration while residual levels were monitored in search of a steady state solution.

The Development And Verification Of Three Matlab Analysis Applications Programmed Specifically For Engage Team Projects., Jonathan W. Huber

Masters Theses

This thesis outlines the development of three analysis applications for use in the freshmen Engineering Fundamentals Program (engage) at the University of Tennessee. Engage teaches freshmen engineering mechanics concepts through a set of integrated components including Lecture, Analysis and Skills, Problem Session, Physical Homework, and Team Projects. Presently, the students have limited access to any software analysis tools to aid the design process. The students have little experience writing the types of complex programs needed to analyze a particular project. Even more, they do not have the time. The applications provide a means for the students to perform an accurate …

A Study On The Prediction Of Viscosity With The Use Of Numerical Simulation Software, Brian Robinson

Masters Theses

A study was undertaken to numerically simulate the flow of highly viscous fluid. Simulating a highly viscous flow within a parallel plate plastometer will hopefully begin to bridge the gaps in the current knowledge of these viscous models. The modeling of this flow was performed using the canned code FiDAP from Fluent Inc. The results are compared with the analytical results calculated by NASA Marshall researchers.

A Study Of The Electron Beam Scattering Under Various Gaseous Environment, Jing He

Masters Theses

There are three objectives in this work: to experimentally measure the profiles of electron beams scattered by interaction with a gas, to measure total scattering cross-sections for gases and to apply the cross-section data in a suitable Monte Carlo simulation to predict beam scattering profiles for comparison with experiment.
The experimentally measured profiles cover a wide range of intensity variation. There are two evidenced regions: an inner region and an outer skirt corresponding to inelastic (small angle) and elastic scattering respectively are appeared. These profiles use the planar p-n junction gives us an overall look at the electron beam spreading, …