Fluid Cavitation Intensity in Zero Leakage Upstream Pumping Face Seals with Spiral Grooves

Abstract

Cavitation intensity variations in fluid lubrication may alter the mechanical and lubrication properties of the fluid. In this paper, a compressible cavitation model is presented to study the effect of fluid cavitation intensity on zero-leakage flow of upstream-pumping spiral grooves face seals (UPSGLFS). The pressure variation in cavities can be calculated considering the compressibility of the lubricating medium, the ratio of minimum pressure to cavitation pressure is further defined to characterize the cavitation intensity. A numerical analysis of the zero-leakage behavior of UPSGLFS is then performed based on its effect. Results show that cavitation plays a negative role in sealing performances. However, the groove’s configuration and working conditions have substantial effects on controlling the cavitation intensity. Meanwhile, whether a circumferential continuous pressure ring above the seal pressure can be formed is the design basis for judging the strict zero leakage of the medium, rather than only depending on the change of leakage rate parameter value. With suitable spiral groove parameter design, zero-leakage design for upstream-pumping seals may be achieved under multi-speed and multi-seal-pressure conditions. Here, a zero-leakage map is presented for working conditions with multi-speed ranging from 500 to 20,000[Formula: see text]rpm and multi-seal pressure ranging from 0.1 to 3.0[Formula: see text]MPa.

Thermal Cavitation Effect on the Hydrodynamic Performance of Spiral Groove Liquid Face Seals

“…For the validation of numerical modeling, in our previous works [36,40], the experi mental cavitation phenomena of submerged journal bearings by Etsion et al [35] and the thrust bearings with texture surfaces by Zhang and Meng [5] were compared and analyzed which verified the effectiveness of this cavitation model in the calculation of pressure inside the cavitation zone and in the analysis of lubrication of texture surfaces. In addition, in an other work [43], the experimental work of the porous face seal surface temperature rise by Dingui and Brunetiere et al [44] was further compared and analyzed, which verified the effectiveness of the model in the analysis of thermo-hydrodynamic lubrication.…”

“…The minimum pressure of the film further demonstrates the ability of phase change. So, the ratio between p min and p c of the lubricating film could be utilized for additional characterization of cavitation intensity [ 40 ], as expressed below. …”

“…The characteristics of the lubricant and sealing ring used [ 36 , 40 , 41 ] in the analysis can be found in Table 3 and Table 4 .…”

“…The characteristics of the lubricant and sealing ring used [36,40,41] in the analysis can be found in Tables 3 and 4. Based on considering thermal and cavitation, its influence is mainly considered from two aspects of seal performance: leakage rate q and opening performance F [39].…”