Elastic deformation of liquid spiral groove face seals operating at high speeds and low pressure

Self Cite

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.

Section: Governing Equationsmentioning

confidence: 99%

Section: Governing Equationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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

Bai

Yang

et al. 2023

Self Cite

“…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.…”

Section: Introductionmentioning

confidence: 99%

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

Chen,

Ma,

Bai

et al. 2024

Self Cite

The property of vaporization phase transition in liquid oxygen face seals is a key factor affecting the stability of mechanical face seals in many fields, especially under cryogenic conditions. Here, a numerical model based on the saturated vapor pressure is established to investigate the vaporization phase transition property of liquid oxygen sealing film. The novelty of this model is to take the influence of heat transfer and face distortions into consideration at the same time. The pressure and temperature distributions as well as face distortions are calculated, and then the property of vaporization phase transition and sealing performance are analyzed. It is found that spiral grooves may lead to the complex film temperature distributions and irregular vaporization distributions. With the increase in seal temperature and decrease in seal pressure, the vaporization area extends from the low-pressure side to the grooves area, and the vaporization rate increases rapidly. The more important thing is that the vaporization often brings a drastic fluctuation and non-monotonic change in opening force. Specifically, with the increase inin seal temperature from 55 K to 140 K, the opening force fluctuates violently, and the fluctuation range is more than 50%, showing an obvious instability. Finally, this study provides a design range of pressure and temperature values for liquid oxygen face seals. In these ranges, this kind of face seals can have a stable operation, which is beneficial to the practice engineering related to the complex properties of sealing fluid.

“…Groove treatment on the rotor surface is a widely used method to improve the heat transfer characteristics and to reduce energy consumption for gas face seals [22,23]. To date, many works have focused on the hydrodynamic effect and sealing performance of gas face seals as influenced by the groove type [24][25][26][27][28][29].…”

Section: Introductionmentioning

confidence: 99%

High-Temperature Flow Behavior and Energy Consumption of Supercritical CO2 Sealing Film Influenced by Different Surface Grooves

Yang,

Wang,

Bai

2023

Self Cite

The Brayton cycle system, as a closed cycle working under high-temperature, high-pressure and high-speed conditions, presents significant prospects in many fields. However, the flow behavior and energy efficiency of supercritical CO2 is severely influenced by the structures of face seals and the sealing temperature, especially when the sealing gas experiment is the supercritical transformation process. Therefore, a numerical model was established to investigate the high-temperature flow behavior and energy consumption of face seals with different surface grooves. The effects of the operation parameters and groove structure on the temperature distribution and sealing performance are further studied. The obtained results show that the supercritical effect of the gas film has a more obvious influence on the flow velocity uθ than ur. Moreover, it can be found that the temperature distribution, heat dissipation and leakage rate of the gas face seals present a dramatic change when the working condition exceeds the supercritical point. For the spiral groove, the change rate of heat dissipation becomes larger, from 3.6% to 8.1%, with the increase in sealing pressure from 15 to 50 MPa, when the temperature grows from 300 to 320 K. Meanwhile, the open force maintains a stable state with the increasing temperature and pressure even at the supercritical point. The proposed model could provide a theoretical basis for seal design with different grooves on the supercritical change range in the future.