ABSTRACT
As turbomachines age, their operational eµectiveness (e.g., thermodynamic e²ciency) and reliability degrade, typically due to one of the following four factors: (1) wear of various forms (including surface erosion), (2) fouling of the process ¨ ow passages or the bearing lubricant, (3) corrosion and/or oxidation, and (4) metal fatigue. ˜e focus of this chapter will be only tribological issues, involving wear, erosion, and lubrication.
