Thermo-Hydrodynamic Lubricating Behaviors of Upstream Liquid Face Seals with Ellipse Dimples

Abstract

In order to obtain the leakage characteristics of an upstream pumping face seal with inclined ellipse dimples under high-temperature and high-speed liquid lubricating conditions, a thermo-hydrodynamic lubricating model is developed. The novelty of this model is that it takes the thermo-viscosity effect and cavitation effect into account. The influence of operating parameters, such as rotational speed, seal clearance, seal pressure, ambient temperature and structural parameters, such as dimple depth, inclination angle, slender ratio and dimple number on the opening force and leakage rate, is numerically calculated. The results obtained show that the thermo-viscosity effect makes the cavitation intensity decrease noticeably, leading to an increase in the upstream pumping effect of ellipse dimples. Moreover, the thermo-viscosity effect may make both the upstream pumping leakage rate and opening force increase by about 10%. It can also be found that the inclined ellipse dimples can produce an obvious upstream pumping effect and hydrodynamic effect. Based on the reasonable design of the dimple parameter, not only can the sealed medium achieve zero leakage, but the opening force can also increase by more than 50%. The proposed model has the potential to provide the theoretical basis for and guide the future designs of upstreaming liquid face seals.

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 experimental 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 another 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.…”

Vaporization Phase Transition in Cryogenic Liquid Oxygen Sealing Film on Spiral Groove Faces

“…But, for liquid face seal, because of the high viscosity of the liquid, the temperature change in the fluid film in the groove area is more drastic than that of the gas seal. Meanwhile, low pressure induced phase transition often occurs in the spiral groove area, especially for the cases of high speed and low pressure [ 24 , 25 ]. Theoretically, it seems that the surface grooves will lead to significant effect on vaporization distribution.…”