Since film rupture is regarded as a mechanism to limit an excessive reduction of film pressure, the cavitation pressure is usually assumed to be lower than the film pressure in the interior. Once the cavitation occurs, this pressure remains constant over the cavitation region and on its boundaries. The Swift-Stieber condition of film rupture is adapted to study short bearing configurations and to locate the cavitation boundaries. By allowing natural boundaries of the film to form in unloaded region and by allowing the film pressure to assume some subambient value, the short bearing theory is extended to describe the cavitation zone.
The origin of the gases contained in the cavity and the nature of film rupture are outlined and some demonstrations of the behaviour of cavity in the divergent film are described. Visual observations in the enclosed gas cavitation zone of a plain journal bearing are described. A camera and a video tape recorder are used to illustrate how the upstream and downstream region of the cavitation develops and evolves in the developed patterns and investigate striation streamers and reverse flows in statically loaded journal bearings.
