Engineering Commons^™

Investigation And Demonstration Of A Rich Combustor Cold Start Device For Alcohol Fueled Engines, David Kim Irick

Doctoral Dissertations

Alcohols (methanol and ethanol) have been identified as having the potential to improve air quality when used to replace conventional gasoline. This potential is primarily due to the different organic species that are emitted by alcohol-fueled engines. The use of "near neat" alcohols gives greater benefits than fuels containing lower levels of alcohol, but neat alcohols present a significant cold starting problem.

The primary objective of this study was to develop a rich combustor device which will extend the cold start range of alcohol fueled engines to -30°C while reducing cold start emissions. In support of this objective a software …

Development Of A Versatile Wide-Angle Lens Characterization Strategy For Use In The Omnister Stereo Vision System, Keith B. Johnson

Masters Theses

This thesis details the development of an accurate and efficient wide-angle stereo vision system. Wide-angle or fisheye stereo is desired because it provides the capa­bility to recover depth information for a large scene from a single stereo image pair. However, nonlinear image distortions caused by the camera optics complicate the necessary stereo processes of camera modeling and disparity analysis . The charac­terization and removal of these lens distortions therefore is considered vital to stereo evaluation of fisheye images. Existing wide-angle stereo systems have maintained the use of pinhole projections to model the respective camera systems . This ideal projection model …

Fracture Toughness Testing With Notched Round Bars, Christopher D. Wilson

Doctoral Dissertations

Current fracture toughness testing is conducted with planar specimens, such as the compact tension C(T) specimen and the single edge bend SE(B) specimen. The crack front in a planar specimen has a constraint condition which varies through the thickness from plane stress on the lateral surfaces to plane strain in the middle of the specimen. This change in constraint makes the geometry of planar specimens three-dimensional; however, two-dimensional analyses based on the assumption of plane stress or plane strain are often performed.

An alternative specimen geometry is the notched round bar (NRB). This axisymmetric geometry has the advantage of constant …

An Experimental Investigation Of Creep And Viscoelastic Properties Using Depth-Sensing Indentation Techniques, Barry Neal Lucas

Doctoral Dissertations

Broad band, quasi-static and frequency specific dynamic techniques adapted to depth-sensing indentation testing have been utilized to measure both time dependent plasticity (creep) at both room and elevated temperatures as well as time dependent elasticity (viscoelasticity) at room temperature.

Indentation Creep

Using a variety of depth-sensing indentation techniques at both room and elevated temperatures, the dependency of the indentation hardness on the variables of indentation strain rate (stress exponent for creep, n) and temperature (apparent activation energy for creep, Q), and the existence of a steady state behavior in an indentation creep test with a Berkovich indenter were investigated. The …

An Investigation Of Unsteady Vortex Flow Over A Maneuvering Delta Wing, Harry James Kowal

Doctoral Dissertations

An investigation of the vortex breakdown phenomenon using flow visualization qualitatively and quantitatively was conducted with a 70° delta wind under conditions of steady and unsteady pitch, roll and combinations of pitch and roll. Testing was carried out in the water tunnel located in the Mechanical Engineering Department of the Royal Military College of Canada, Kingston, Ontario.

Steady state roll experiments with the delta wing pitched at 30° showed that the behavior of vortex breakdown as a function of roll angle could be considered linear over the front half of the delta wing; however, the behavior beyond a certain critical …

The Design And Implementation Of A Field-Scale Monitoring System To Evaluate Spatial Variability Within Production Cotton Fields, Michael Spencer Palmer

Masters Theses

Much interest has been focused on site-specific crop production since the introduction of grain yield monitoring systems. Considerable research has been conducted in the area of site-specific grain production. Lack of a cotton yield monitor has slowed implementation of site-specific practices in cotton production. However, due to the intense level of management corrunonly associated with in cotton production. it may prove to be an ideal crop for site-specific practices.

Preliminary testing was conducted in the fall of 1995 to verify that a batch weighing system used in conjunction with Global Positioning System (GPS) equipment was a satisfactory method of monitoring …