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Consideration Of Wear Rates At High Velocity, Chad S. Hale
Consideration Of Wear Rates At High Velocity, Chad S. Hale
Theses and Dissertations
The development of the research presented here is one in which high velocity relative sliding motion between two bodies in contact has been considered. The experimental results of a VascoMax 300 maraging steel slipper sliding on an AISI 1080 steel rail during a January 2008 sled test mission were considered for the determination of high velocity wear rates. The numerical model, based on a metallographic study of a test slipper, contained all of the physical features present in order to adequately characterize high velocity wear rates. Two-dimensional, plane strain models have been implemented in the explicit finite element code, ABAQUS. …
Wear Analysis Of Cu-Al Coating On Ti-6al-4v Under Fretting, Karl N. Murray
Wear Analysis Of Cu-Al Coating On Ti-6al-4v Under Fretting, Karl N. Murray
Theses and Dissertations
The effects of changes in the coefficient of friction (CoF) between the contacting surfaces on the fretting wear characteristics of Cu-Al coating on Ti-6Al-4V were investigated. This Cu-Al coating is part of a system that is applied to titanium turbine blades to reduce fretting at the interface. In the application, there is a solid lubricant that is added on top of the coating as an assembly aid and to help reduce the friction while the lubricant remains within the contact. Previous studies have researched the characteristics of the coating without the additional lubricant. In this study, liquid motor oil was …
Analysis Of Computational Methods For The Treatment Of Material Interfaces, Minh C. Nguyen
Analysis Of Computational Methods For The Treatment Of Material Interfaces, Minh C. Nguyen
Theses and Dissertations
Rocket sled tests at the Air Force Research Laboratory's Holloman High Speed Test Track frequently approach velocities where gouging development becomes the limiting factor to achieving higher operating velocities. Direct observation of the gouging process is not possible so computational modeling is necessary to study the phenomenon. Since gouging development is dependent on the impact surface conditions, the method used to model material interfaces directly affects the accuracy of the solution. Three methods are available in the hydrocode CTH to handle material interfaces: 1) materials are joined at the interface, 2) a frictionless slide line is inserted, and 3) a …
Turbine Blade Surface Roughness Effects On Shear Drag And Heat Transfer, Jess W. Drab
Turbine Blade Surface Roughness Effects On Shear Drag And Heat Transfer, Jess W. Drab
Theses and Dissertations
This work used scaled samples of actual turbine blade surfaces to characterize correlations between turbine surface roughness, friction coefficient, and convective heat transfer rate-parameters which affect an engine's efficiency and the blade's lifespan. For erosion/deposits, friction coefficients up to 250 times higher and convective heat transfer coefficients of up to 150 times higher were found when compared to a flat plate baseline. Other roughness types (pitting and fuel deposits) yielded less dramatic results. These results did not follow existing friction coefficient-to-heat transfer coefficient correlations, such as the Reynolds analogy. While these analytical and empirical correlations hold for flat plates, they …