Parametric Study of the Behavior of a Mechanical Face Seal Operating in Mixed and TEHD Lubrication Regimes

2012 ◽  
Author(s):  
André Parfait Nyemeck ◽  
Noël Brunetière ◽  
Bernard Tournerie
Keyword(s):  
Heat Transfer ◽  
Friction Coefficient ◽  
Mixed Lubrication ◽  
Operating Conditions ◽  
Fluid Viscosity ◽  
Face Seal ◽  
Lubrication Regimes ◽  
Lubrication Regime ◽  
Mechanical Face Seal ◽  
Mixed Lubrication Regime

In this paper, the behavior of a mechanical face seal is analyzed for different operating conditions and designs. For that, a theoretical model including a multiscale approach of the mixed lubrication regime, heat transfer and deformation of the seal rings is used. It has been possible to clearly identify the three different lubrication regimes of a mechanical seal: the mixed lubrication where the friction coefficient decreases, the rough hydrodynamic regime corresponding to an increasing friction and then the thermo-elasto-hydrodynamic (TEHD) regime for which the coefficient of friction is approximately constant. In this work, the influence of the fluid pressure, the seal roughness height, the balance ratio, the rings materials, the dry friction coefficient and viscosity are respectively examined. Generally speaking, the variation of these parameters affects the location of the optimum value of the friction coefficient in the mixed lubrication regime. In the TEHD regime, the temperature is mainly influenced by the materials and the fluid viscosity, which control the amplitude of deformation and heat transfer. A dimensionless parametric analysis has been carried out in order to perform an overall discussion of the results. It is shown that the mixed and rough hydrodynamic lubrication regimes are controlled by the modified duty parameter, while the TEHD regime is controlled by the sealing parameter.

scholarly journals Friction coefficient in mixed lubrication: A simplified analytical approach for highly loaded non-conformal contacts

2017 ◽  
Vol 9 (7) ◽  
pp. 168781401770626 ◽  
Author(s):  
Javier Echávarri Otero ◽  
Eduardo de la Guerra Ochoa ◽  
Enrique Chacón Tanarro ◽  
Benito del Río López
Keyword(s):  
Friction Coefficient ◽  
Thermal Effects ◽  
Mixed Lubrication ◽  
Good Precision ◽  
Experimental Conditions ◽  
Lubrication Regime ◽  
Line Contacts ◽  
Mixed Lubrication Regime ◽  
Lubrication Conditions ◽  
Highly Loaded

This article presents an analytical model for predicting friction in mixed lubrication regime. The calculations consider load shared between roughness asperities and the lubricant film, as well as the appearance of thermal effects in the contact and the influence of the lubricant rheology. Tests using tribometers have been performed to measure the friction coefficient in non-conformal surfaces for both point and line contacts. This allows verifying the results of the model under a broad range of experimental conditions with an influence on the lubrication conditions. Reasonably good precision has been found in the results obtained, which combined with a simplicity of use confers the model a high practical utility for rough estimates of the friction coefficient under mixed lubrication.

A Friction Model for Cold Strip Rolling With Two-Wavelength Surface Roughness in the “Mixed” Lubrication Regime

2003 ◽  
Vol 125 (3) ◽  
pp. 670-677 ◽  
Author(s):  
H. R. Le ◽  
M. P. F. Sutcliffe
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Rolling Direction ◽  
Hydrodynamic Pressure ◽  
Friction Model ◽  
Mixed Lubrication ◽  
Strip Rolling ◽  
Lubrication Regime ◽  
Mixed Lubrication Regime ◽  
Cold Metal

A two-dimensional friction model has been developed for cold metal rolling in the “mixed” lubrication regime. Roughness is modelled using superimposed short and long wavelength asperities with a lay orientated along the rolling direction. The hydrodynamic pressure in the lubricant is solved using Reynolds’ equation, coupled with the crushing process of the two-wavelength roughness. This allows for the solution of film thickness and contact area ratio and hence friction coefficient through the roll-bite. The model extends the authors’ earlier model [15] by allowing for a variation in hydrodynamic pressure across the width of the contact. Predictions for both the surface roughness and the friction coefficient are in reasonable agreement with published measurements.

A New Approach to Determine Lubrication Regimes of Piston-Ring Assemblies

1997 ◽  
Vol 119 (4) ◽  
pp. 808-816 ◽  
Author(s):  
Naeim A. Henein ◽  
Shengqiang Huang ◽  
Walter Bryzik
Keyword(s):  
Piston Ring ◽  
Hydrodynamic Lubrication ◽  
Mixed Lubrication ◽  
Spark Ignition Engine ◽  
Frictional Torque ◽  
New Approach ◽  
Lubrication Regimes ◽  
Lubrication Regime ◽  
Mixed Lubrication Regime ◽  
And Shifts

A new approach is developed to determine piston-ring assembly lubrication regimes from the instantaneous frictional torque measured for the whole engine. This is based on the variation of the friction coefficient with the duty parameter in the Stribeck diagram over the mixed and hydrodynamic lubrication regimes. The derived equation determines the lubrication regimes from the slope of the line in the Stribeck diagram. A single cylinder spark ignition engine was instrumented to determine the total instantaneous frictional torque of the engine. Experiments were conducted under different loads at a constant speed. Results show that the regime is mixed lubrication near the top dead center (TDC) and shifts to the hydrodynamic lubrication regime as the piston moves away from TDC. The extent of the mixed lubrication regime depends on engine load and speed.

The influence of surface texturing on the transition of the lubrication regimes between a piston ring and a cylinder liner

2016 ◽  
Vol 18 (8) ◽  
pp. 785-796 ◽  
Author(s):  
Chunxing Gu ◽  
Xianghui Meng ◽  
Youbai Xie ◽  
Di Zhang
Keyword(s):  
Piston Ring ◽  
Surface Texturing ◽  
Cylinder Liner ◽  
Mixed Lubrication ◽  
Textured Surface ◽  
Asperity Contact ◽  
Lubrication Regimes ◽  
Lubrication Regime ◽  
Mixed Lubrication Regime ◽  
Stribeck Curves

This article employs a mixed lubrication model to investigate the performance of the textured surface. The Jakobsson–Floberg–Olsson model is used to obtain the hydrodynamic support of the textured conjunction, while the calculation of the asperity contact load is based on the load-sharing concept. Based on the simulated Stribeck curves of the smooth surface and the textured surface, comparisons are conducted to study the effect of texturing under different lubrication regimes. It appears that the transition of lubrication regimes is influenced by the texturing parameters and the convergence degrees of conjunction. The presence of textures delays the appearance of the mixed lubrication regime and the boundary lubrication regime.

Experimental Thermal Analysis of a Mechanical Face Seal

2016 ◽  
Vol 8 (3) ◽  
Author(s):  
K. Ayadi ◽  
N. Brunetière ◽  
B. Tournerie ◽  
A. Maoui
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Thermal Effects ◽  
Inverse Method ◽  
Fluid Pressure ◽  
Operating Conditions ◽  
Mechanical Seal ◽  
Face Seal ◽  
Rotating Speed ◽  
Mechanical Face Seal

An experimental study quantifying the thermal behavior of a mechanical seal is performed. Temperature measurements are obtained using embedded thermocouples within the stator at different locations, and the tests are carried out at different sealed fluid pressures and rotary shaft speeds. Furthermore, an inverse method is used to calculate the heat transfer from the measured local temperatures. The Nusselt number is calculated along the wetted surface as a function of operating conditions; the obtained values are discussed in comparison to previous works. Our results demonstrate that the amplitude of the thermal effects is highly dependent on the operating conditions. The temperature rise being increased by 600% when the rotating speed is raised from 1000 to 6000 rpm and the fluid pressure from 1 to 5 MPa. Moreover, the temperature can vary by several degrees when the distance from the wetted diameter (cooled by convection) and the friction face (heat source) is varied from less than 2 mm.

scholarly journals Modelling tribochemistry in the mixed lubrication regime

2019 ◽  
Vol 132 ◽  
pp. 265-274 ◽  
Author(s):  
Abdullah Azam ◽  
Ali Ghanbarzadeh ◽  
Anne Neville ◽  
Ardian Morina ◽  
Mark C.T. Wilson
Keyword(s):  
Mixed Lubrication ◽  
Lubrication Regime ◽  
Mixed Lubrication Regime

Thermoelastohydrodynamic Behavior of Mechanical Gas Face Seals Operating at High Pressure

2007 ◽  
Vol 129 (4) ◽  
pp. 841-850 ◽  
Author(s):  
Sébastien Thomas ◽  
Noël Brunetière ◽  
Bernard Tournerie
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Numerical Modeling ◽  
Face Seal ◽  
Inertia Effects ◽  
Real Gas ◽  
Choked Flow ◽  
Face Seals ◽  
Mechanical Face Seal ◽  
Gas Expansion

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.

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