Influence of tilt angle and grinding angle of the plate on friction and transfer layer formation
In the present investigation, unidirectional grinding marks were attained on the steel plates. Experiments were then conducted using pins of high purity Al, pure Mg and Al-Mg alloys against the prepared steel plates using an inclined pin-on-plate sliding tester. The inclination angle of the plate was varied in the tests and for each inclination angle, the pins were slid both perpendicular and parallel to the unidirectional grinding marks direction under both dry and lubricated conditions. Results showed that the friction, transfer layer formation, and the presence of stick-slip motion significantly depend on the grinding marks direction and tilt angle of the hard surfaces under both dry and lubricated conditions for all the three materials investigated.
Effect of Surface Topography on Friction and Transfer Layer during Sliding
Surface topography influences friction and transfer layer formation during sliding. In the present investigation, various kinds of surface topography were produced on steel plates. Pins made of metals (pure Al, Cu and Pb) and alloys (Al-4Mg and Al-8Mg) were then slid against prepared steel plates using inclined pin-on-plate sliding tester to understand the role of surface topography of harder surface and load on friction and transfer layer formation under both dry and lubricated conditions. It was observed that the transfer layer formation and coefficient of friction along with its two components, namely adhesion and plowing, are strongly dependent on surface topography and independent of surface roughness (Ra). The plowing component of friction was highest for the surface that promotes plane strain conditions and lowest for the surface that promotes plane stress conditions near the surface.
Numerical Simulation for Natural State of Two-Phase Liquid Dominated Geothermal Reservoir with Steam Cap Underlying Brine Reservoir
Hydrothermal reservoir which liquid-dominated hydrothermal reservoir is a type of geothermal reservoir that most widely used for power plant. The exploitation of mass and heat from the geothermal fluid will decrease the pressure in the reservoir over time. Therefore the pressure drop in the reservoir will have an impact on the formation of boiling zones or boiling will increase. The impacts are an increase in the fraction of steam, dryness, in the reservoir and with good vertical permeability will form a steam cap underlying the brine reservoir. The two- phase liquid dominated reservoir is sensitive to the porosity and difficult to assign average properties of the entire reservoir when there is boiling zone in some area of the reservoir. These paper showed successful development of two-phase liquid dominated geothermal reservoir and discussed the formation of steam cap above brine reservoir through numerical simulation for state natural conditions. The natural state modeling in steam cap shows a match with the conceptual model of the vapor-dominated developed. These paper also proofed the presence of transition zone, boiling zone, between steam cap and brine reservoir.