关键词: 沟槽参数, 液膜密封, 空化诱发, JFO空化边界, 空穴度

Abstract: In order to further explore the cavitation inducements of liquid film seals and their regular influences,based on the Jakobsson-Floberg-Olsson (JFO)cavitation boundary,physical model of liquid film seals with spiral groove in the middle and double dam areas was established. The accuracy of the programmed algorithm was verified by cavitation visualization experiment,and the cavitation characteristics of liquid film seals under different cavitation boundaries was analyzed. Effects of groove parameters such as groove depth,groove angle and groove number on the location of liquid film rupture and reformation as well as the cavitation occurrence area were probed into,with the changes of pressure and density of the lubricant between the sealing faces as the criterion. Results showed that cavitation characteristics calculated by JFO cavitation boundary can be better matched with the experiment results,compared with Half-Sommerfeld and Reynolds cavitation boundaries. Both larger groove depth and groove angle are help to shorten the cavitation length along the helical direction at the locus of liquid film rupture and the cavitation width along the circumferential direction at the locus of liquid film reformation,and the former promotes the cavitation degree of the two locations while the latter reducing that of the liquid film reformation location. Increasing groove angle enlarges the cavitation sizes of the two locations and also promotes the cavitation degrees of the corresponding locations. Cavitation area in the liquid film decreases linearly as groove depth increases and it shows a linear upward trend as groove angle is small followed by a parabolic increase trend with increasing groove angle. When groove number is more than 12,the cavitation area takes on a linear decrease trend as it increases.

Key words: groove parameters, liquid film seals, cavitation induction, JFO cavitation boundary, cavitation degree