Oil film pressure of journal bearing in automobile

JBTR

1. OIL FILM PRESSURE OF A
HYDRODYNAMIC JOURNAL BEARING –
COMPARISON BETWEEN FEA &
EXPERIMENTS

2. •BATCH MEMBERS:
Under the Supervision of:
Mr. ------------ A.P/Mech, SPCET

3. NEED FOR THE PRESENT STUDY
In practice, the experimental cost for the journal bearing is too
costly
To reduce the experimental cost for the journal bearing used in
any machine by the use of simulation study.
This is the reason to conduct the simulation study for the oil film
pressure of a hydrodynamic journal bearing under the influence
of various lubricating oils.

4. OBJECTIVE
•The power density in various machines is increasing year by year due to
growing demand for mechanical and economic efficiency.
•Today bearings are very wide spread, particularly due to their use in
internal combustion engines and power transferring machines.
•Bearings are depends on many parameters such as oil pressure, viscosity
of lubricant, load on bearing, inertia of fluid, torque etc. out of which oil-
film pressure plays an important role in operation of journal bearing.
•The main objective of the present study is to estimate the oil-film
pressure of a hydrodynamic journal bearing using finite element analysis
and compared with the experimental results.

5. INTRODUCTION
•A bearing is a machine element which support another moving machine element(
known as journal).
• It permits a relative motion between the contact surfaces of the members, while
the carrying load.
• Due to the relative motion between the contact surfaces, a certain amount of
power is wasted in overcoming frictional resistance.
• If the rubbing surfaces are in direct contact, there will be rapid wear.
•In order to reduce frictional resistance and wear and in some cases to carry away
the heat generated, a layer of fluid( known as lubricant) may be provided.
•The lubricant used to separate the journal and bearing is usually a mineral oil
refined from petroleum, but vegetable oils, silicon oils, greases etc., may be
used.

6. Lubricants used in the present study
1.SAE5W40
2.SAE10W40
3.SAE15W40
4.SAE20W40
5.Paraffin oil
6

7. 7
Properties Standard SAE5W40 SAE10W40 SAE15W40 SAE20W40Paraffin oil
Viscosity @100°C
(cSt)
ASTM D445 14.8 14.5 15.0 15.5 13.2
Pour point (°C)ASTM D97 -45 -36 -36 -21 -47
Flash point(°C)ASTM D92 226 210 232 250 206
Viscosity indexASTM D2270 151 152 146 155 135
Specific gravity @
15°C
ASTM D287 0.855 0.863 0.865 0.872 0.860
Mean
Wear scar diameter
(mm)
ASTMD4172 0.6015 0.6135 0.5972 0.5845 0.6235
TESTED PROPERTIES OF LUBRICATING OILS

8. SIMULATION SOFTWARE
•In practice many industries implement the COMSOL
MULTIPHYSICS SOFTWARE for simulating oil-film
pressure of a hydrodynamic journal bearing.
•This simulation tool very comfortable with real time problems
induced in the any industries.

9. 9
The journal bearing geometry is modeled in FEA based COMSOL multiphysics
approach.
The Reynolds equation in the FEA based COMSOL multiphysics approach is used
to derive the oil film pressure of the journal bearing system as given below:
In the above equation, ρ is the density (kg/m
3
), h is the lubricating oil thickness (m), η
is the viscosity (Pa·s), p is the oil film pressure (Pa), a is the channel base location (m),
V
a
is the channel base tangential velocity (m/s), b is the solid wall location (m), and V
b

is the tangential velocity (m/s) of the solid wall and also considered the rotating
journal as the solid wall.
FEA BASED COMSOL MULTIPHYSICS APPROACH

10. 10
Oil-film Pressure (MPa) of SAE5W40

11. 11
Oil-film Pressure (MPa) of SAE10W40

12. Oil-film Pressure (MPa) of SAE15W40
12

13. 13
Oil-film Pressure (MPa) of SAE20W40

14. Oil-film Pressure (MPa) of Paraffin oil

15. JOURNAL BEARING TEST RIG
JOURNAL BEARING

16. SPECIFICATIONS OF JOURNAL BEARING TEST RIG
Journal outer diameter & material 39.9mm & En31-Steel
Test bearing size & material 40mm & Bronze
Radial load
Minimum Load 150 N and
Maximum Load 10 kN
Oil tank cap 5 lit
Oil reservoir capacity 500ml
Loading ratio 1:5
Journal Speed 200 to 3000 rpm

17. Experimental results - Oil-film thickness (μm)
Lubricating Oils Oil-film thickness (μm)
SAE5W40 65
SAE10W40 57
SAE15W40 70
SAE20W40 75
Paraffin Oil 54
17

18. Experimental results - Oil-film thickness (μm)

19. Lubricating Oils
Oil-film pressure (MPa)
COMSOL Results Experimental results
SAE5W40 7.7 7.8
SAE10W40 7.9 8.1
SAE15W40 7.6 7.8
SAE20W40 7.4 7.7
Paraffin Oil 8.2 8.4
Experimental Results –oil film pressure (MPa)

20. Comparison – COMSOL & Experimental Results
(MPa)

21. Results & Discussion
•The viscosity of the SAE20W40 plays a significant role used to
obtain the minimum oil film pressure in FEA model and also the
experimental result is showed the same. The viscosity of the
SAE20W40 is greater than that of other lubricating oils.
•The finite element analysis and experimental value of an oil-film
pressure of SAE20W40 is 7.4 and 7.7 MPa respectively. The finite
element analysis and experimental value of an oil-film pressure of
SAE5W40, SAE10W40, SAE15W40 & Paraffin oil is 7.7, 7.9, 7.6, 8.2
and 7.8, 8.1, 7.8, 8.4MPa respectively.
•The results from both FEA and experiment showed that the oil film
pressure of SAE20W40 is minimum compared with the other
lubricating oils.
21

22. Continue…….
•FEA results are good agreed with the experimental results.
•The SAE20W40 has the higher viscosity index (VI) of 155
between all the tested lubricating oils. This high viscosity
index, offers maximum viscosity of the lubricating oil
(SAE20W40) through much more of the bearing surface
with a corresponding low viscosity index lubricating oils.
•However, the oil-film thickness of the lubricating oil is
maximum, oil-film pressure is minimum [3,9]. In the
present study, oil film thickness for SAE20W40 is maximum.
This is the reason oil-film pressure for SAE20W40 is
minimum compared with other lubricating oils.

23. Conclusions
•Using COMSOL oil-film pressure for journal bearing is simulated and
compared with experimental results. It is found that COMSOL gives
better results, hence COMSOL solution get validated with
experimental results.
•The SAE20W40 has the higher viscosity index (VI) between all the
tested lubricating oils. However, the oil-film thickness of the
lubricating oil is maximum, oil-film pressure is minimum. In the
present study, oil film thickness for SAE20W40 is maximum. This is
the reason oil-film pressure for SAE20W40 is minimum compared
with the other lubricating oils.
•FEA results are good agreed with the experimental results.

24. REFERENCES
[1] Valkonen, A.; Juhanko, J. & Kuosmanen, P. - 22-24 April 2010
“Measurement of Oil Film Pressure In Hydrodynamic Journal Bearings”
[2] Ravindra R Nvathar, Dr.N.V. Halegowda – 2012 “Experimental
Investigation Of Oil Film Thickness For Hydrodynamic Journal Bearings” ,
applied mechanics and materials vols. 110 – 116, pp 2377 – 2382.
[3] Chaitanya K Desai and Dilip C Patel - 2005 “Experimental Analysis of
Pressure Distribution of Hydrodynamic Journal Bearing: A Parametric Study”,
ICME 05-AM-30.
[4] L Costa1, A S Miranda1*, M Fillon2 and J C P Claro1- Feb 1, 2003 “An
Analysis Of The Influence Of Oil Supply Conditions On The Thermo
Hydrodynamic Performance of A Single Groove Journal Bearing”, vol 217,
133-144.

25. [5] Diyar I. Ahmed, Kasolang S, Basim A. Khidhir and Yousif B F. (2013)
‘Analysis of Factors Interaction for Maximum Oil-Film Pressure in Hydrodynamic
Journal Bearing’, Caspian Journal of Applied Sciences Research., Vol 2 (6), pp 60-
73.
[6] R. K. Naffin and L. Chang. (2010) ‘An Analytical Model for the Basic Design
Calculations of Journal Bearings’, Journal of Tribology., Vol 132, pp 1-7.
[7] Bhaumik S. and Pathak S. D. (2015) ‘Analysis of Anti-Wear Properties of CuO
Nanoparticles as Friction Modifiers in Mineral Oil (460cSt Viscosity) Using Pin-
On-Disk Tribometer’, Tribology in Industry., Vol 37(2), pp 196-203.
[8] Kirtee L. Chidle and R. N. Baxi (2016) ‘CFD analysis of fluid film journal
bearing: a review’, International Research Journal of Engineering and Technology.,
Vol 3 (1), pp 845-850.
REFERENCES

26. [9] Diyar I. Ahmed, Kasolang S, Basim A. Khidhir and Yousif B F. (2013)
‘Fuzzy Logic based Model to Predict Maximum Oil-Film Pressure in Journal
Bearing’, Research Journal of Applied Sciences, Engineering and
Technology., Vol 6 (20), pp 3871-3878.
[10] Gang Liu. (2015) ‘Numerical Calculation and Analysis of Water-
lubricated Stern Bearing Considering Elastic Hydrodynamic’, Advanced
Materials Research., Vol 1061-1062, pp 653-657.
REFERENCES

27. THANK YOU…