Abstract
The aim of this study is to present a numerical model of thermohydrodynamic mechanical face seals to analyze the influence of operating and design parameters. This type of seal is equipped with a notched rotating face and is generally used in heavy-duty applications. The experience showed that thermohydrodynamic mechanical face seals are efficient for high pressures and at high velocities by reducing the friction coefficient. However, when parameters such as the number of notches and size are not optimized, extensive damage to the seal faces can be observed.
The operating principle for this type of seal has been qualitatively explained but not demonstrated. The notches are assumed to create periodic thermoelastic deformations of the rotating face, thereby improving the hydrodynamic lift and avoiding contact of the faces. To analyze the validity of this principle, we developed a finite element model, resolving the Reynolds and energy equations and taking account of cavitation, face deformations, and heat transfer in the seal rings. The results show that waviness appears on the notched face but that the other face, made of carbon, exhibits a very similar wave pattern due to elastic deformation. This therefore reduces the expected hydrodynamic effect. The model is then used to carry out a parametric study in order to analyze the seal's behavior and performance.
ACKNOWLEDGEMENTS
The Sealing Technology Department of the CETIM is due particular thanks for supporting this research project.
Review led by Tom Lai