Technical Brief

The Importance of the Heat Capacity of Lubricants With Nanoparticles in the Static Behavior of Journal Bearings

[+] Author and Article Information
Rodrigo Nicoletti

Department of Mechanical Engineering,
São Carlos School of Engineering,
University of São Paulo,
Trabalhador São-Carlense 400,
São Carlos 13566-590, Brazil
e-mail: rnicolet@sc.usp.br

Contributed by the Tribology Division of ASME for publication in the JOURNAL OF TRIBOLOGY. Manuscript received March 14, 2014; final manuscript received May 26, 2014; published online July 15, 2014. Assoc. Editor: George K. Nikas.

J. Tribol 136(4), 044502 (Jul 15, 2014) (5 pages) Paper No: TRIB-14-1058; doi: 10.1115/1.4027861 History: Received March 14, 2014; Revised May 26, 2014

Nanoparticle additives increase the viscosity of lubricants, thus being an interesting solution for improving the load carrying capacity of hydrodynamic bearings. But, nanoparticles also change the thermal properties of the lubricant. Would these thermal properties be important to the static characteristics of lubricated bearings? The answer is yes, being the volumetric heat capacity an important parameter. In this work, the static behavior of journal bearings is studied when nanoparticles are added to the lubricant. A thermohydrodynamic analysis is performed with oil ISO VG68 (base fluid) and six different nanoparticles are considered as additives: Si, SiO2, Al, Al2O3, Cu, and CuO. The numerical results show that the bearing load capacity can be increased up to 10%, not only because of the higher viscosity, but also because of the higher volumetric heat capacity of the lubricant with nanoparticles. Higher volumetric heat capacity of the lubricant decreases temperature development in the bearing gap, thus resulting in higher viscosity distribution for the same operating conditions. In fact, the best results were obtained with ISO VG68 + copper oxide (CuO), whose volumetric heat capacity is the highest among the tested nanofluids. Such results were not equaled when only the viscosity of the lubricant had been changed.

Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.


Wu, Y. Y., and Kao, M. J., 2011, “Using TiO2 Nanofluid Additive for Engine Lubrication Oil,” Ind. Lubr. Tribol., 63(6), p. 440445. [CrossRef]
Qiu, S., Dong, J., Chen, G., and Zhou, Z., 1999, “Preparation of Ni Nanoparticles and Evaluation of Their Tribological Performance as Potential Additives in Oils,” ASME J. Tribol., 123(3), pp. 441–443. [CrossRef]
Prasad, B. K., Rathod, S., Yadav, M. S., and Modi, O. P., 2010, “Effects of Some Solid Lubricants Suspended in Oil Toward Controlling the Wear Performance of a Cast Iron,” ASME J. Tribol., 132(4), p. 041602. [CrossRef]
Padgurskas, J., Rukuiza, R., Prosycevas, I., and Kreivaitis, R., 2013, “Tribological Properties of Lubricant Additives of Fe, Cu and Co Nanoparticles,” Tribol. Int., 60(1), pp. 224–232. [CrossRef]
Shenoy, B. S., Binu, K. G., Pai, R., Rao, D. S., and Pai, R. S., 2012, “Effect of Nanoparticles Additives on the Performance of an Externally Adjustable Fluid Film Bearing,” Tribol. Int., 45(1), pp. 38–42. [CrossRef]
Kalakada, S. B., Nair, K. P., and Rajendrakumar, P. K., 2013, “Mathematical Models for the Viscosity-Temperature Relationship of the Lubricants Containing Nanoparticles and Its Application to Journal Bearings,” Int. J. Nanopart., 6(4), pp. 296–311. [CrossRef]
Yang, Z., Diao, D., Fan, X., and Fan, H., 2014, “Nanoparticles-Laden Gas Film in Aerostatic Thrust Bearings,” ASME J. Tribol., 136(3), p. 034501. [CrossRef]
Santos, I. F., and Nicoletti, R., 1999, “THD Analysis in Tilting-Pad Journal Bearings Using Multiple Orifice Hybrid Lubrication,” ASME J. Tribol., 121(4), pp. 892–900. [CrossRef]
Stachowiak, A. W., and Bachelor, A., 2014, Engineering Tribology, 4th ed., Butterworth-Heinemann, Waltham, MA.
Huminic, G., and Huminic, A., 2012, “Application of Nanofluids in Heat Exchangers: A Review,” Renewable Sustainable Energy Rev., 16(8), pp. 5625–5638. [CrossRef]
Koo, J., and Kleinstreuer, C., 2005, “Laminar Nanofluid Flow in Microheat-Sinks,” Int. J. Heat Mass Transfer, 48(13), pp. 2652–2661. [CrossRef]
Einstein, A., 1906, “Eine neue bestimmung der Molekuldimensionen,” Ann. Phys., 324(2), pp. 289–306. [CrossRef]
Drew, D. A., and Passman, S. L., 1999, Theory of Multicomponent Fluids, Springer-Verlag, Berlin.
Incropera, F. P., and Dewitt, D. P., 1990, Fundamentals of Heat and Mass Transfer, 3rd ed., Wiley, New York.
Duchowski, J. K., 1998, “Examination of Journal Bearing Filtration Requirements,” Lubr. Eng., 54(9), pp. 18–38.
Mizuhara, K., Tomimoto, M., and Yamamoto, T., 2000, “Effects of Particles on Lubricated Friction,” Tribol. Trans., 43(1), pp. 51–56. [CrossRef]
Tomimoto, K., 2003, “Experimental Verification of a Particle Induced Friction Model in Journal Bearings,” Wear, 254(7–8), pp. 749–762. [CrossRef]
Khanafer, K., and Vafai, K., 2012, “A Critical Synthesis of Thermophysical Characteristics of Nanofluids,” Int. J. Heat Mass Transfer, 54(19–20), pp. 4410–4428. [CrossRef]


Grahic Jump Location
Fig. 1

Journal bearing in study

Grahic Jump Location
Fig. 3

Percentage variation of the bearing load capacity in comparison to the base fluid

Grahic Jump Location
Fig. 4

Percentage variation of the physical properties of the nanofluids in comparison to the base fluid (φ=4%)

Grahic Jump Location
Fig. 5

Percentage variation of the thermal capacity (ρC) of the nanofluids in comparison to the base fluid (φ=4%)

Grahic Jump Location
Fig. 6

Percentage variation of the temperature in the bearing gap in comparison to the base fluid

Grahic Jump Location
Fig. 2

Percentage variation of the bearing load capacity using nanofluids in comparison to the base fluid (φ=4%)



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In