Cavitation development in the lubricant film of a reciprocating piston-ring assembly

Abstract

The onset and development of cavitation in the lubrication film present throughout the stroke between the piston ring and the cylinder liner in a reciprocating test rig was visualized by a charge-coupled device (CCD) camera and monitored by a miniature pressure sensor. Various transient cavitation patterns were identified during the stroke, ranging from developing fern-shaped cavities to string cavities extending gradually up to the trailing edge of the piston ring. Both the onset and the development of these cavities seem to be affected by piston speed and load; at higher speeds cavities appear later in the stroke and are larger in size, while at higher loads they appear earlier, are more numerous and, thus, smaller in size.