Numerical study of the oil whirl phenomenon in a hydrodynamic journal bearing

  • Mohamad Hamed HekmatEmail author
  • Gholam Ali Biukpour
Technical Paper


The journal bearings are one of the main components of the rotating machines and always bear considerable weight and dynamic stresses. Bearing defect may cause bending and eventually axis fracture and, in some cases, lead to an increase in the temperature of other components. One of the most important challenges of this type of bearings is the instability of the oil film layer, which appears as oil whirl and oil whip. The main objective of this research is the numerical analysis of the journal bearing of a centrifugal pump and the investigation of variations in the eccentricity and the rotation of the bearing to detect the instability resulting from the oil whirl and whip. For this purpose, assuming the steady and laminar flow, the Reynolds theory modified by the Elrod–Adams cavitation model is utilized. In addition, the finite element method is used for the numerical solution. The results indicate that the pressure on the bearing shell increases considering the effect of the oil whip phenomenon. Moreover, by increasing the eccentricity ratio, the pressure applied to the bearing increases and the mass fraction of the oil film decreases. After that, in order to improve the performance, by creating a horizontal groove in a simple bearing (without groove), the oil whirl and whip are numerically analyzed and the effect of the eccentricity as well as the rotational speed of the modified bearing is investigated. Numerical results indicate that the presence of the groove in the bearings causes the pressure on the grooved bearings to decrease dramatically. As a result, the probability of occurrence of the oil instability phenomenon in this case will be less than simple state (no groove). In addition, in this case, it could be observed that as the rotational speed of the grooved bearing increased, the pressure applied around the groove bearing from the oil film increases. However, the pressure applied to the grooved bearings is much less than the pressure applied to the simple bearings.


Journal bearing Horizontal oil groove Oil whirl Oil whip Numerical simulation 



  1. 1.
    Berry JE (2005) Oil whirl and whip instabilities—within journal bearings, Machinery Lubrication Magazine, Issue Number 200505Google Scholar
  2. 2.
    Scott R (2005) Journal bearings and their lubrication, Machinery Lubrication MagazineGoogle Scholar
  3. 3.
    Cha Matthew YJ (2015) Dynamic performance and design aspects of compliant fluid film bearings, Ph.D. thesis, KTH Royal Institute of Technology, School of Industrial Engineering and Management, Department of Machine Design, SwedenGoogle Scholar
  4. 4.
    Ehrich FF (1976) Self-excited vibration. Shock and vibration handbook. McGraw-Hill, New YorkGoogle Scholar
  5. 5.
    Groper M, Etsion I (2002) Reverse flow as a possible mechanism for cavitation pressure build-up in a submerged journal bearing. J Tribol 124(2):1–7CrossRefGoogle Scholar
  6. 6.
    Newkirk BL, Taylor HD (1925) Shaft whirling due to oil action in journal bearing. Gen Electric Rev 28(8):559–568Google Scholar
  7. 7.
    Rao JS, Raju RJ, Reddy KVB (1970) Experimental investigation on oil whip of flexible rotor. Tribology 3(2):100–103CrossRefGoogle Scholar
  8. 8.
    Muszynska A (1988) Stability of whirl and whip in rotor/bearing systems. J Sound Vib 127:49–64CrossRefGoogle Scholar
  9. 9.
    Wu CW, Ma GJ (2005) Abnormal behavior of a hydrodynamic lubrication journal bearing caused by wall slip. Tribol Int 38(5):492–499CrossRefGoogle Scholar
  10. 10.
    El-Shafei A, Tawfick SH, Raafat MS, Aziz GM (2007) Some experiments on oil whirl and oil whip. J Eng Gas Turbines Power 129(1):144–153CrossRefGoogle Scholar
  11. 11.
    Roy L, Laha SK (2008) Steady state and dynamic characteristics of axial grooved journal bearings. Tribol Int 42:754–761CrossRefGoogle Scholar
  12. 12.
    Castro HF, Cavalca KL, Nordmann R (2008) Whirl and whip instabilities in rotor-bearing system considering a nonlinear force model. J Sound Vib 317:273–293CrossRefGoogle Scholar
  13. 13.
    Schweizer B (2009) Oil whirl oil whip and whirl/whip synchronization occurring in rotor Systems with full-floating bearing. Nonlinear Dyn 57(4):509–532zbMATHCrossRefGoogle Scholar
  14. 14.
    Dhande DY, Pande DW, Chatarkar V (2013) Analysis of hydrodynamic journal bearing using fluid structure interaction approach. Int J Eng Trends Technol 4(8):3389–3392Google Scholar
  15. 15.
    Gao G, Yin Z, Jiang D, Zhang X (2014) Numerical analysis of plain journal bearing under hydrodynamic lubrication by water. Tribol Int 75:31–38CrossRefGoogle Scholar
  16. 16.
    Dimitri AS, Mahfoud J, El-Shafei A (2016) Oil whip elimination using fuzzy logic controller. J Eng Gas Turbines Power 138(6):062502CrossRefGoogle Scholar
  17. 17.
    Nagare PN, Patil GV (2016) A comparative study on numerical solution of Reynolds equation of journal bearing. In: IEEE international conference on automatic control and dynamic optimization techniques (ICACDOT), pp 893–895Google Scholar
  18. 18.
    Javorova J, Mazdrakova A (2017) Squeeze film effect at elasto-hydrodynamic lubrication of plain journal bearings. Sci Eng Educ 1(1):11–20Google Scholar
  19. 19.
    Alakhramsing S, Ostayen R, Eling R (2015) Thermo-hydrodynamic analysis of a plain journal bearing on the basis of a new mass conserving cavitation algorithm. Lubricants 3:256–280CrossRefGoogle Scholar
  20. 20.
    Dhande DY, Pande DW (2017) A two-way FSI analysis of multiphase flow in hydrodynamic journal bearing with cavitation. J Braz Soc Mech Sci Eng 39(9):3399–3412CrossRefGoogle Scholar
  21. 21.
    Dhande DY, Pande DW, Lanjewar GH (2018) Numerical analysis of three lobe hydrodynamic journal bearing using CFD–FSI technique based on response surface evaluation. J Braz Soc Mech Sci Eng 40:393CrossRefGoogle Scholar
  22. 22.
    Lin Q, Bao Q, Li K, Khonsari MM, Zhao H (2018) An investigation into the transient behavior of journal bearing with surface texture based on fluid-structure interaction approach. Tribol Int 118:246–255CrossRefGoogle Scholar
  23. 23.
    Zhang Y, Li X, Dang C, Hei D, Wang X, Lü Y (2019) A semianalytical approach to nonlinear fluid film forces of a hydrodynamic journal bearing with two axial grooves. Appl Math Model 65:318–332MathSciNetCrossRefGoogle Scholar
  24. 24.
    Buuren S (2013) Modeling and simulation of porous journal bearings in multibody systems, Ph.D. thesis, Karlsruhe Institute of Technology, GermanyGoogle Scholar
  25. 25.
    Elrod HG, Adams M (1974) A computer program for cavitation and starvation problems. Cavitation and related phenomena in lubrication. In: Proceedings of the 1st Leeds–Lyon symposium on tribology, University of Leeds, Leeds, Mechanical Engineering Publications Ltd, LondonGoogle Scholar
  26. 26.
    Vijayaraghavan D, Keith TG Jr (1989) Development and evaluation of a cavitation algorithm. Tribol Trans 32(2):225–233CrossRefGoogle Scholar
  27. 27.
    Profito FJ, Giacopini M, Zachariadis DC, Dini D (2015) A general finite volume method for the solution of the Reynolds lubrication equation with a mass-conserving cavitation model. Tribol Lett 60:18–21CrossRefGoogle Scholar
  28. 28.
    Singh U, Roya L, Sahu M (2008) Steady-state thermo-hydrodynamic analysis of cylindrical fluid film journal bearing with an axial groove. Tribol Int 41:1135–1144CrossRefGoogle Scholar
  29. 29.
    COMSOL Multiphysics (2015) Version: 5.2. COMSOL Inc., BurlingtonGoogle Scholar
  30. 30.
    COMSOL (2013) CFD module model library manualGoogle Scholar
  31. 31.
    Bergmann P, Grün F, Gódor I, Stadler G, Maier-Kiener Verena (2018) On the modelling of mixed lubrication of conformal contacts. Tribol Int 125:220–236CrossRefGoogle Scholar
  32. 32.
    Shinde AB, Pawar PM (2017) Multi-objective optimization of surface textured journal bearing by Taguchi based Grey relational analysis. Tribol Int 114:349–357CrossRefGoogle Scholar
  33. 33.
    Mane RM, Soni S (2013) Analysis of hydrodynamic plain journal bearing. In: Proceedings of the 2013 COMSOL conference, IndiaGoogle Scholar

Copyright information

© The Brazilian Society of Mechanical Sciences and Engineering 2019

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringTafresh UniversityTafreshIran

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