Experimental and numerical study of wavy mechanical face seals operating under pressure inversions

Abstract

This paper investigates the impact of the face waviness and pressure inversions on the leakage and on the outer fluid entry of mechanical face seals using a numerical model and an experimental setup. The numerical model couples a transient Reynolds equation, an analytical contact model, a force balance solver, and a solver for the thermo-mechanical deformations. The experimental tests on a face seal with low waviness and on a face seal with high waviness provide leakage and outer fluid entry data, which are reproduced by the model. Contrary to the face seal with low waviness, the face seal with high waviness has poor performance and the pressure inversions increase significantly the ingression of outer fluid. The parametric study shows a decrease of leakage with increasing spring force, and an increase of leakage and outer fluid entry with increasing values of waviness amplitude. The higher leakage observed for wavy seals is shown to be due to the higher average film thickness, and to some extent due to the mechanisms associated with waviness: hydrodynamic pressure generation, film squeeze and stretching.

Keywords

Face seal pressure inversion waviness seal dynamics thermo-mechanical deformations experimental numerical transient behaviour

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References

Bur BH. Rock bit face seal having anti-rotation pins. Patent 6,176,330 B1, USA, 2001.

Throp RE, Eason, EM and Borsos C. Pressure compensation and rotary seal system for measurement while drilling instrumentation. Patent 8,739,897 B2, USA, 2014.

Harp

Salant

. Analysis of mechanical seal behavior during transient operation. J Tribol 1998; 120: 191–197.

Paul

Salant

. Electronically controlled mechanical seal for aerospace applications—Part II: Transient tests. Tribol Transact 1995; 38: 51–56.

Nau

. Mechanical seal face materials. Proc IMechE, Part J: J Engineering Tribology 1997; 210: 165–183.

Minet

Brunetière

Tournerie

et al. Analysis and modeling of the topography of mechanical seal faces. Tribol Transact 2010; 53: 799–815.

Lubbinge H. On the lubrication of mechanical face seals. PhD Thesis, University of Twente, Twente, The Netherlands, 1999.

Flitney

Nau

. A study of factors affecting mechanical seal performance. Proc IMechE, Part A: J Power and Energy 1987; 201: 17–28.

Lebeck

. Mechanical loading – a primary source of waviness in mechanical face seals. ASLE Transact 1997; 20: 195–208.

10.

Young

Lebeck

. The design and testing of a wavy-tilt-dam mechanical face seal. Lubricat Eng 1997; 45: 322–329.

11.

Lebeck AO and Young LA. Wavy-tilt-dam seal ring, Patent 4,836,561 A, USA, 1987.

12.

Brunetière

Tournerie

Frêne

. TEHD lubrication of mechanical face seals in stable tracking mode. Part 2 – Parametric study. J Tribol 2003; 125: 617–627.

13.

Ying

Wei

Yongjian

et al. Mechanism of a wavy-tilt-dam mechanical seal under different working conditions. Tribol Int 2015; 90: 43–54.

14.

Mayer E. Thermohydrodynamics in mechanical seals. In: 4th International conference on fluid sealing, Philadelphia, 5 May 1969, pp.124–129.

15.

Djamai

Brunetière

Tournerie

. Numerical modeling of a thermohydrodynamic mechanical face seals. Tribol Transact 2010; 53: 414–425.

16.

Brunetière N and Wang QJ. A simplified mass-conservating and continuous cavitation model. In: 2011 STLE annual meeting and exhibition, Atlanta, Georgia, 15–19 May 2011.

17.

Brunetière

. A general model for liquid and gas lubrication, including cavitation. J Tribol 2018; 140: 350–354.

18.

Saadat

Flint

. Expressions for the viscosity of liquid/vapour mixtures: predicted and measured presure distributions in a hydrostatic bearing. Proc IMechE, Part J: J Engineering Tribology 1996; 210: 75–79.

19.

Bonneau

Huitric

Tournerie

. Finite element analysis of grooved gas thrust bearings and grooved gas face seals. ASME J Tribol 1993; 115: 348–354.

20.

Faria

. An efficient finite element procedure for analysis of high-speed spiral groove gas face seals. ASME J Tribol 2001; 123: 205–210.

21.

Bonneau

Hajjam

. Modelisation de la rupture et de la reformation des film lubrifiants dans les contacts elastohydrodynamiques. Rev Eur Elem Finis 2001; 10: 679–704.

22.

Greenwood

Williamson

JBP

. Contact of nominally flat surfaces. Proc Roy Soc 1966; 295: 300–318.

23.

Brunetière N and Tournerie B. Garnitures mécaniques d'étanchéité – Lubrification hydrodynamique et mixte Garnitures mécaniques d'étanchéité Lubrification hydrodynamique et mixte. Les Techniques de l'Ingénieur, 2016 (BM5422v1).

24.

Becker

. Measurements of convective heat transfer from a horizontal cylinder rotating in a pool of water. Int J Heat Mass Transfer 1963; 12: 1053–1062. .

25.

Salencon J. Mécanique des Milieux Continus – 1. Concepts Généraux. Ellipses, 1988.

26.

Adjemout

Brunetière

Bouyer

. Friction and temperature reduction in a mechanical face seal by a surface texturing: comparison between TEHD simulations and experiments. Tribol Transact 2018; 61: 1084–1094.

27.

Cochain J. Numerical and experimental study of misaligned and wavy mechanical face seals operating under pressure pulses and inversions. PhD Thesis, University of Poitiers, France, 2018.

28.

Standard-NFISO6296: 2001. Dosage de l'eau – méthode de titrage Karl Fisher par potentionmétrie.