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A 3-D surface topography measurement system was constructed for the surface characterization of an area. This system consists of a personal computer, a microdisplacement stage and a surface profilometer. The microdisplacement system moves the samples laterally for successive traces and ensures the parallelism of each surface profile. The personal computer coordinates the stage movement and surface profile measurements, provides large data storage, and allows rapid data manipulation. This system provides an easy, effective way to characterize a surface, together with versatile displays to observe and record surface topography. It has been used for wear-scar characterization and paint-defect detection. A relocation fixture was incorporated with the 3-D surface-measurement system to provide a powerful tool to observe progressive changes in the surface topography during tribological tests.

The steady flow-field inside a monolith catalytic converter was examined by means of water-flow visualization. These tests, conducted with transparent, full-scale converter models with several different header geometries, showed that flow invariably separated from the inlet-header diffuser walls. A constant-diameter jet proceeded to the front monolith face, where it impacted and expanded to cover the substrate frontal area. For some visualization tests, the jet was constrained within a transparent tube which was translated toward the front monolith face, simulating shorter and shorter headers. The monolith internal flow field and pressure loss were found to be unaffected until the tube was within a few centimeters of the substrate. A converter with very short inlet and outlet headers is termed a truncated converter.

Accumulation of fuel, water, acids, insolubles, and metals in engine oil is documented and compared for variable-fueled (fuel containing up to 85 percent methanol) and gasoline-fueled vehicles in short-trip service. The oil temperature at which various contaminants are removed is noted. As a consequence of emulsion formation, the viscosity of the oil in the M85-fueled vehicles increased. Due to the presence of gasoline, the viscosity of the oil in the gasoline-fueled vehicles decreased. Equations were developed to explain both the viscosity reduction due to gasoline and the viscosity increase due to emulsion-forming contaminants (water and methanol).

Using standard industry tests, the oxidation stability of General Motors current factory-fill automatic transmission fluid (ATF) was compared to that of a proposed factory-fill ATF to be introduced for the 1995 Model Year. Full-scale transmission tests and Aluminum Beaker Oxidation Tests run at various temperatures showed that a proposed factory-fill fluid is substantially more resistant to oxidation than the current factory-fill ATF. Using Total Acid Number increase (Δ-TAN) as the measure of oxidation, a minimum of 35% improvement was obtained with a proposed factory fill. This improvement at least doubles the time to “perceived fluid failure” (Δ-TAN = 2.5).