Numerical and experimental study of misaligned and wavy mechanical face seals operating under pressure pulses and inversions


Nom: 
Jérémy Cochain
Lieu Evenemement: 
Amphithéâtre IFMI
Date: 
Jeudi, 31 Mai, 2018 - 14:30
Description: 

Numerical and experimental study of misaligned and wavy mechanical face seals operating under pressure pulses and inversions


Face seals are mechanical devices used to seal rotating shafts in numerous applications. While they can operate efficiently under steady conditions for years, they tend to fail prematurely when operating in severe, or rapidly varying conditions. The focus of this research is the development and use of an experimental and a numerical method to investigate the impact of pressure pulses, pressure inversions and induced dynamic loading on the performance of mechanical face seals exhibiting face misalignment and waviness. The fluid solver of a state-of-the art face seal numerical model was extended to transient conditions and a module for solving the dynamics for the axial and angular degrees of freedom of a flexibly-mounted stator was added. A system-level experimental setup generating pressure pulses was instrumented and methods to characterise the performance of the face seal in terms of oil volume loss and ingression of water outer-fluid were selected and implemented.
Face seals, with flat and misaligned faces, operating under pressure pulses and pressure inversions were experimentally tested and simulated. They showed only slight increase of water in the oil, no increase over time, and no measurable oil leakage. The low water ingression is due to the low film thickness combined with the short duration of the pressure inversions. An exploratory face seal of high waviness was also experimentally tested. Contrary to the other parameters, the waviness appears to significantly increase the leakage and promote water ingression and could thus be at the origin of some seal failures.

Departement: 
D3







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