Calculation Methods of a Wavy-Tilt-Dam Mechanical Face Seal with Asymmetry Circumferential Waviness

Author(s):  
Yidong Duan ◽  
Heshun Wang ◽  
Weibing Zhu ◽  
Chening Zhang ◽  
Zepei Huang
2007 ◽  
Vol 129 (4) ◽  
pp. 841-850 ◽  
Author(s):  
Sébastien Thomas ◽  
Noël Brunetière ◽  
Bernard Tournerie

A numerical modeling of thermoelastohydrodynamic mechanical face seal behavior is presented. The model is an axisymmetric one and it is confined to high pressure compressible flow. It takes into account the behavior of a real gas and includes thermal and inertia effects, as well as a choked flow condition. In addition, heat transfer between the fluid film and the seal faces is computed, as are the elastic and thermal distortions of the rings. In the first part of this paper, the influence of the coning angle on mechanical face seal characteristics is studied. In the second part, the influence of the solid distortions is analyzed. It is shown that face distortions strongly modify both the gap geometry and the mechanical face seal’s performance. The mechanical distortions lead to a converging gap, while the gas expansion, by cooling the fluid, creates a diverging gap.


Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1285
Author(s):  
Wentao He ◽  
Shaoping Wang ◽  
Chao Zhang ◽  
Xi Wang ◽  
Di Liu

The service life of mechanical face seals is related to the lubrication and wear characteristics. The stable analytical methods are commonly used, but they cannot address effects of random vibration loading, which, according to experimental studies, are important factors for lubrication and wear of mechanical face seals used in air and space vehicles. Hence, a dynamic model for mechanical face seals is proposed, with a focus on the effects of random vibration loading. The mechanical face seal in the axial direction is described as a mass-spring-damping system. Spectrum analysis specified for random vibration is then performed numerically to obtain the response power spectral density (PSD) of the mechanical face seal and calculate the root mean square (RMS) values under random vibration conditions. A lumped parameter model is then developed to examine how dynamic parameters such as stiffness and damping affect the lubrication regimes of mechanical face seals. Based on the dynamic model and Archard wear equation, a numerical wear simulation method is proposed. The results elucidated that the increase of input acceleration PSDs, the decrease of axial damping, and the increase of axial stiffness lead to the probability of the mechanical face seal operating under full film lubrication regime increase and finally the decrease of wear. This research provides a guideline for improving the adaptability of mechanical face seals under random vibration environments.


1982 ◽  
Vol 104 (4) ◽  
pp. 439-447 ◽  
Author(s):  
L. A. Young ◽  
A. O. Lebeck

In this paper the results of experimental investigations of the effects of radial taper on mechanical face seals are presented and compared to theory. The previously published theory considers the effects of thermal taper caused by a temperature gradient in the seal rings; mixed friction in the case where load support is shared between hydrostatic support and partial contact of the seal faces; surface roughness, which affects both load sharing and leakage; and wear, which alters the radial profile. Fifteen tests were run using a 100 mm diameter carbon versus tungsten carbide seal at 1800 rpm and 3.45 MPa in water. Test duration was up to 100 hr. Varying amounts of radial taper were used. Tests were run at balance ratios of 1.00 and 0.75. Initial and final surface profiles were recorded. Seal torque, leakage, and face temperatures were recorded as functions of time. Results show that theory predicts initial torque and leakage as functions of initial taper quite well, given knowledge of seal surface characteristics. Predicted equilibrium thermal taper as a function of torque for a balance ratio of 1.0 is good. For a seal having a balance ratio of 0.75, predicted equilibrium thermal rotation shows some agreement but more experimental data are needed. The results of 1.00 balance ratio tests suggest that after a long period of operation, any initial taper will be worn away and the seal would continue to operate as a parallel face seal. Results from long-term tests indicate that the wear coefficient is not a constant. While the experimental results support the basic concepts of the model, the results show where further work must be done to better understand the role of surface roughness and wear processes in mechanical face seals.


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