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Articles 1 - 14 of 14

Full-Text Articles in Mechanical Engineering

Variational Asymptotic Micromechanics Modeling Of Composite Materials, Tian Tang Dec 2008

Variational Asymptotic Micromechanics Modeling Of Composite Materials, Tian Tang

All Graduate Theses and Dissertations

The issue of accurately determining the effective properties of composite materials has received the attention of numerous researchers in the last few decades and continues to be in the forefront of material research. Micromechanics models have been proven to be very useful tools for design and analysis of composite materials. In the present work, a versatile micromechanics modeling framework, namely, the Variational Asymptotic Method for Unit Cell Homogenization (VAMUCH), has been invented and various micromechancis models have been constructed in light of this novel framework. Considering the periodicity as a small parameter, we can formulate the variational statements of the ...


A Three-Dimensional, Time-Dependent Circulation Model Of Utah Lake, Eric V. Callister Dec 2008

A Three-Dimensional, Time-Dependent Circulation Model Of Utah Lake, Eric V. Callister

All Graduate Theses and Dissertations

Spatial and temporal variations of Utah Lake’s flow field were modeled using the Estuary Lake and Computer Model from the Centre for Water Research (CWR-ELCOM) at the University of Western Australia as part of an effort to increase understanding of the lake’s natural processes in order to restore the lake to its pristine, clear-water state and preserve the habitat of the June sucker, an endangered species. The model was validated using temperature measurements taken by sensors in 2007. The water temperature was a strong function of air temperature and incident short wave radiation, and was influenced to a ...


Fabrication Of Long-Fiber-Reinforced Metal Matrix Composites Using Ultrasonic Consolidation, Yanzhe Yang Dec 2008

Fabrication Of Long-Fiber-Reinforced Metal Matrix Composites Using Ultrasonic Consolidation, Yanzhe Yang

All Graduate Theses and Dissertations

This research is a systematic study exploring a new fabrication methodology for long-fiber-reinforced metal matrix composites (MMCs) using a novel additive manufacturing technology. The research is devoted to the manufacture of long-fiber-reinforced MMC structures using the Ultrasonic Consolidation (UC) process. The main objectives of this research are to investigate the bond formation mechanisms and fiber embedment mechanisms during UC, and further to study the effects of processing parameters on bond formation and fiber embedment, and the resultant macroscopic mechanical properties of UC-made MMC structures. From a fundamental research point of view, bond formation mechanisms and fiber embedment mechanisms have been ...


Development Of A Mathematical Model For 3d Reconstruction Of Target Objects By Photogrammetry, Keith F. Blonquist Dec 2008

Development Of A Mathematical Model For 3d Reconstruction Of Target Objects By Photogrammetry, Keith F. Blonquist

All Graduate Theses and Dissertations

This thesis outlines the development of a mathematical model which can be used to perform 3D reconstruction of a target object from surveillance images. 3D reconstruction is a common procedure in photogrammetry, but performing 3D reconstruction from surveillance images can be more difficult than typical photogrammetry applications.

Surveillance images are generally captured in an unsystematic manner because there is no control over the target that is being photographed. Surveillance images can have a wide variety of fields of view, are often captured with uncalibrated cameras, and typically the targets are objects for which there is no other a priori information ...


Modeling, Designing, Fabricating, And Testing Of Channel Panel Flat Plate Heat Pipes, James R. Harris Dec 2008

Modeling, Designing, Fabricating, And Testing Of Channel Panel Flat Plate Heat Pipes, James R. Harris

All Graduate Theses and Dissertations

Flat plate heat pipes are very efficient passive two-phase heat transport devices. Their high e'ciency and low mass are desirable in the aerospace and electronics industries. The highly competitive nature of the thermal management industry results in little awareness of the capabilities of at plate heat pipes, which has resulted in only a few applications of the technology. In the year 2000 a research and development project sponsored by Space Dynamics Laboratory was launched to investigate building carbon-based at heat pipes. The at conguration is desireable to incorporate many components onto one thermal management system. Development led to the ...


Angles-Only Navigation For Autonomous Orbital Rendezvous, David Charles Woffinden Dec 2008

Angles-Only Navigation For Autonomous Orbital Rendezvous, David Charles Woffinden

All Graduate Theses and Dissertations

The proposed thesis of this dissertation has both a practical element and theoretical component which aim to answer key questions related to the use of angles-only navigation for autonomous orbital rendezvous. The first and fundamental principle to this work argues that an angles-only navigation filter can determine the relative position and orientation (pose) between two spacecraft to perform the necessary maneuvers and close proximity operations for autonomous orbital rendezvous. Second, the implementation of angles-only navigation for on-orbit applications is looked upon with skeptical eyes because of its perceived limitation of determining the relative range between two vehicles. This assumed, yet ...


Hydrogen Production Using Geothermal Energy, Theodore Wayne Hand Dec 2008

Hydrogen Production Using Geothermal Energy, Theodore Wayne Hand

All Graduate Theses and Dissertations

With an ever-increasing need to find alternative fuels to curb the use of oil in the world, many sources have been identified as alternative fuels. One of these sources is hydrogen. Hydrogen can be produced through an electro-chemical process. The objective of this report is to model an electrochemical process and determine gains and or losses in efficiency of the process by increasing or decreasing the temperature of the feed water. In order to make the process environmentally conscience, electricity from a geothermal plant will be used to power the electrolyzer. Using the renewable energy makes the process of producing ...


Particle Characterization And Consentration Using Aerodynamic Vectoring, Zac Humes Dec 2008

Particle Characterization And Consentration Using Aerodynamic Vectoring, Zac Humes

All Graduate Theses and Dissertations

An experimental demonstration of a new, non-contact particle characterization technique called Aerodynamic Vectoring Particle Sorting (AVPS) is presented. AVPS uses secondary blowing and suction control flows'flows that are a fraction of the jet flow rate'to sharply change the direction of a planar, particle-laden jet. As the jet is vectored, particles present in the flow experience a resultant drag force, dependent upon their size, that balances inertia. Since this balance determines the particle's trajectory, vectoring the flow leads to a separation of particles downstream. This simple, low-pressure-drop sorting technique classifies particles with less risk of damage or contamination ...


Estimating The Subsonic Aerodynamic Center And Moment Components For Swept Wings, W. F. Phillips, Doug F. Hunsaker, R. J. Niewoehner Jun 2008

Estimating The Subsonic Aerodynamic Center And Moment Components For Swept Wings, W. F. Phillips, Doug F. Hunsaker, R. J. Niewoehner

Mechanical and Aerospace Engineering Faculty Publications

An improved method is presented for estimating the subsonic location of the semispan aerodynamic center of a swept wing and the aerodynamic moment components about that aerodynamic center. The method applies to wings with constant linear taper and constant quarter-chord sweep. The results of a computational fluid dynamics study for 236 wings show that the position of the semispan aerodynamic center of a wing depends primarily on aspect ratio, taper ratio, and quarter-chord sweep angle. Wing aspect ratio was varied from 4.0 to 20, taper ratios from 0.25 to 1.0 were investigated quarter-chord sweep angles were varied ...


Axisymmetric Coanda-Assisted Vectoring, Dustin S. Allen May 2008

Axisymmetric Coanda-Assisted Vectoring, Dustin S. Allen

All Graduate Theses and Dissertations

An examination of parameters affecting the control of a jet vectoring technique used in the Coanda-assisted Spray Manipulation (CSM) is presented. The CSM makes use of an enhanced Coanda effect on axisymmetric geometries through the interaction of a high volume primary jet flowing through the center of a collar and a secondary high-momentum jet parallel to the first and adjacent to the convex collar. The control jet attaches to the convex wall and vectors according to known Coanda effect principles, entraining and vectoring the primary jet, resulting in controllable r-θ directional spraying. Several control slots (both annular and unique sizes ...


Pipe5 Finite Element Analysis For Buried Structures, David Aldous May 2008

Pipe5 Finite Element Analysis For Buried Structures, David Aldous

All Graduate Theses and Dissertations

PIPE5 is a two-dimensional finite element analysis program for buried structure analysis. The program has gone through several changes over the years. Some of the features that were added in the latest revision are stress stiffening, corotational formulation, bandwidth minimization, residual monitoring, and dynamic memory allocation. Some parts of the program were also rewritten to make them clearer and improve their performance. After the modifications several comparisons were made to other programs and earlier versions of the program to test the accuracy of the program in its latest form.


Time-Resolved Piv And Pressure Measurements Of Oscillating And Pulsating Flow In A Diffuser, Cameron V. King May 2008

Time-Resolved Piv And Pressure Measurements Of Oscillating And Pulsating Flow In A Diffuser, Cameron V. King

All Graduate Theses and Dissertations

Separating oscillating and pulsating flows in an internal adverse pressure gradient geometry are studied experimentally. Simultaneous velocity-pressure measurements demonstrate that the minor losses associated with oscillating flow in an adverse pressure gradient geometry can be smaller or larger than for steady flow. Separation is found to begin high in the diffuser and propagate downward. Flows are able to remain attached further into the diffuser with larger Reynolds numbers, larger stroke lengths, and smaller diffuser angles. The extent of separation grows with Lo/h. The minor losses grow with increasing displacement amplitude in the range 10 < Lo/h < 40. Losses decrease with Re in the range of 380


Estimating The Subsonic Aerodynamic Center And Moment Components For Swept Wings, W. F. Phillips, Doug F. Hunsaker, R. J. Niewoehner Jan 2008

Estimating The Subsonic Aerodynamic Center And Moment Components For Swept Wings, W. F. Phillips, Doug F. Hunsaker, R. J. Niewoehner

Mechanical and Aerospace Engineering Faculty Publications

An improved method is presented for estimating the subsonic location of the semispan aerodynamic center of a swept wing and the aerodynamic moment components about that aerodynamic center. The method applies to wings with constant linear taper and constant quarter-chord sweep. The results of a computational fluid dynamics study for 236 wings show that the position of the semispan aerodynamic center of a wing depends primarily on aspect ratio, taper ratio, and quarter-chord sweep angle. Wing aspect ratio was varied from 4.0 to 20, taper ratios from 0.25 to 1.0 were investigated, quarter-chord sweep angles were varied ...


Photoelectric Charging By Ultraviolet Light Of A Lunar Dust Simulant In A Microgravity Environment, Microgravity Research Team 2008 Jan 2008

Photoelectric Charging By Ultraviolet Light Of A Lunar Dust Simulant In A Microgravity Environment, Microgravity Research Team 2008

Reports and Proposals

No abstract provided.