Tribology Letters

, 65:75 | Cite as

Fluorescence Tracking and µ-PIV of Individual Particles and Lubricant Flow in and Around Lubricated Point Contacts

  • V. Strubel
  • S. Simoens
  • P. Vergne
  • N. Fillot
  • F. Ville
  • M. El Hajem
  • N. Devaux
  • A. Mondelin
  • Y. Maheo
Methods paper


This paper deals with optical experimental methods for improving current knowledge on particle entrapment in elastohydrodynamic contacts. Particular attention was paid to the possibilities offered by fluorescence-based techniques for mapping lubricant flow and tracking contaminant trajectories. A ball-on-disk tribometer, a fluorescent medium, and particle image velocimetry equipment were used together for this purpose. This original experimental setup enabled us to obtain lubricant streamlines and velocity vector maps in the contact area. Moreover, it allowed us, for the first time, to capture the details of trapping as the rejection of contaminating particles, in the context of lubrication, as it happened. Dynamic in situ observations clearly showed that the entrapment of debris-like particles was competing against the backflow occurring upstream, in particular in elliptical contacts. The results reported in this work confirm and expand previous results obtained with different methods, i.e., using a twin-disk machine and CFD computations. Finally, we briefly describe as future work the potential for applying these fluorescence-based methods to questions that are still under debate in the lubrication community.


Particle entrapment Particle tracking Particle image velocimetry Fluorescence Point contacts Elliptical contacts 

List of symbols


Hertzian radius or ellipse semi-axis in the x-direction (μm)


Ellipse semi-axis in the y-direction (μm)

\(k = b/a\)

Ellipticity ratio (−)


Number of pixels of the camera sensor along the x-direction (−)


Number of pixels of the camera sensor along the y-direction (−)


Hertzian pressure (MPa)


Ball radius or radius of curvature in the x-direction (mm)


Radius of curvature in the y-direction (mm)


Time (s)


Sequential lighting time (s)


Mean entrainment speed (m/s) = (U1 + U2)/2


Velocity of the disk at the contact location in the x-direction (m/s)


Velocity of the metallic sample (ball- or barrel-shaped) at the contact location in the x-direction (m/s)


Normal load (N)

\(\Delta t\)

Synchronized separation time (s)

\(\Delta t_{x}\)

Synchronized separation time defined in the x-direction (s)

\(\Delta t_{y}\)

Synchronized separation time defined in the y-direction (s)

\(\Delta X\)

Size of the camera image in x-direction (m)



This work was carried out at the Laboratoire de Mecanique des Contacts et des Structures (LaMCoS) and was funded by the “Lubricated Interfaces for the Future” research chair established between INSA Lyon and the SKF company. The authors acknowledge Guillermo Morales-Espejel (SKF-ERC) for his technical expertise.


  1. 1.
    Albahrani, S.M.B., Philippon, D., Vergne, P., Bluet, J.M.: A review of in situ methodologies for studying elastohydrodynamic lubrication. Proc. Inst. Mech. Eng. Part J J. Eng. Tribol. 230(1), 86–110 (2016)CrossRefGoogle Scholar
  2. 2.
    Grant, I.: Particle image velocimetry: a review. Proc. Inst. Mech. Eng. Part C J. Mech. Eng. Sci. 211(1), 55–76 (1997)CrossRefGoogle Scholar
  3. 3.
    Santiago, J.G., Wereley, S.T., Meinhart, C.D., Beebe, D.J., Adrian, R.J.: A particle image velocimetry system for microfluidics. Exp. Fluids 25(4), 316–319 (1998)CrossRefGoogle Scholar
  4. 4.
    Nogueira, S., Sousa, R.G., Pinto, A., Riethmuller, M.L., Campos, J.: Simultaneous PIV and pulsed shadow technique in slug flow: a solution for optical problems. Exp. Fluids 35(6), 598–609 (2003)CrossRefGoogle Scholar
  5. 5.
    Bair, S., Qureshi, F., Winer, W.O.: Observations of shear localization in liquid lubricants under pressure. J. Tribol. 115(3), 507–513 (1993)CrossRefGoogle Scholar
  6. 6.
    Reddyhoff, T., Choo, J.H., Spikes, H.A., Glovnea, R.P.: Lubricant flow in an elastohydrodynamic contact using fluorescence. Tribol. Lett. 38(3), 207–215 (2010)CrossRefGoogle Scholar
  7. 7.
    Horvat, F.E., Braun, M.J.: Comparative experimental and numerical analysis of flow and pressure fields inside deep and shallow pockets for a hydrostatic bearing. Tribol. Trans. 54(4), 548–567 (2011)CrossRefGoogle Scholar
  8. 8.
    Li, J.X., Höglund, E., Westerberg, L.G., Green, T.M., Lundström, T.S., Lugt, P.M., Baart, P.: µPIV measurement of grease velocity profiles in channels with two different types of flow restrictions. Tribol. Int. 54, 94–99 (2012)CrossRefGoogle Scholar
  9. 9.
    Ponjavic, A., Chennaoui, M., Wong, J.S.S.: Through-thickness velocity profile measurements in an elastohydrodynamic contact. Tribol. Lett. 50(2), 261–277 (2013)CrossRefGoogle Scholar
  10. 10.
    Albahrani, S. M. B.: Photoluminescent CdSe/CdS/ZnS quantum dots for temperature and pressure sensing in elastohydrodynamic contacts. PhD Thesis defended on March 22, 2016 at INSA-Lyon, 2016LYSEI016, Université de Lyon (2016)Google Scholar
  11. 11.
    Molimard, J., Querry, M., Vergne P.: New tools for the experimental study of EHD and limit lubrications. In: Dowson, D., et al. (ed.) Proceedings of the 25th Leeds-Lyon Symposium on Tribology “Lubrication at the Frontier”. Lyon, 8–11 September 1998. Tribology Series 36, pp. 717–726. Elsevier (1999)Google Scholar
  12. 12.
    Reiss, P., Chandezon, F.: Nanocristaux semi-conducteurs fluorescents. Techniques de l’Ingénieur, N M 2(030), 1–15 (2004)Google Scholar
  13. 13.
    Adrian, R.J.: Particle-imaging techniques for experimental fluid mechanics. Rev. Fluid Mech. 23(1), 261–304 (1991)CrossRefGoogle Scholar
  14. 14.
    Simoens, S., Ayrault, M.: Concentration flux measurements of a scalar quantity in turbulent flows. Exp. Fluids 16(3), 273–281 (1994)CrossRefGoogle Scholar
  15. 15.
    Boedec, T., Simoens, S.: Instantaneous and simultaneous planar velocity field measurements of two phases for turbulent mixing of high pressure sprays. Exp. Fluids 31(5), 506–518 (2001)CrossRefGoogle Scholar
  16. 16.
    Hsiao, H.-S.S., Hamrock, B.J., Tripp, J.H.: Stream functions and streamlines for visualizing and quantifying side flows in EHL of elliptical contacts. J. Tribol. 123(3), 603–607 (2001)CrossRefGoogle Scholar
  17. 17.
    Bruyere, V., Fillot, N., Morales-Espejel, G.E., Vergne, P.: A two-phase flow approach for the outlet of lubricated line contacts. J. Tribol. 134(4), 041503 (2012)CrossRefGoogle Scholar
  18. 18.
    Strubel, V., Fillot, N., Ville, F., Cavoret, J., Vergne, P., Mondelin, A., Maheo, Y.: Particle entrapment in hybrid lubricated point contacts. Tribol. Trans. 59(4), 768–779 (2016)CrossRefGoogle Scholar
  19. 19.
    Habchi, W., Demirci, I., Eyheramendy, D., Morales-Espejel, G.E., Vergne, P.: A finite element approach of thin film lubrication in circular EHD contacts. Tribol. Int. 40(10–12), 1466–1473 (2007)CrossRefGoogle Scholar
  20. 20.
    Doki-Thonon, T.: Thermal effects in elastohydrodynamic spinning circular contacts. PhD Thesis defended on July, 3 2012 at INSA-Lyon, 2012ISAL0058. INSA de Lyon (2012)Google Scholar
  21. 21.
    Cann, P. M., Sayles, R. S., Spikes, H. A., Ioannides, E., Hamer, J. C.: Direct observation of particle entry and deformation in a rolling EHD contact. In: Dowson, D., et al. (ed.) Proceedings of 22nd Leeds-Lyon Symposium on Tribology “The Third Body Concept: Interpretation of Tribological Phenomena”. Lyon, 5–8 September 1995. Tribology Series 31, pp. 127–134. Elsevier (1996)Google Scholar
  22. 22.
    Chinas-Castillo, F., Spikes, H. A.: Behaviour of colloidally-dispersed solid particles in very thin film lubricated contacts. In: Dowson, D. et al. (ed.) Proceedings of the 26th Leeds-Lyon Symposium on Tribology “Thinning Films and Tribological Interfaces”. The University of Leeds, 14–17 September 1999. Tribology Series 38, pp. 719–731. Elsevier (2000)Google Scholar
  23. 23.
    Dwyer-Joyce, R.S.: The life cycle of a debris particle. In: Dowson, D. et al. (ed.) Proceedings of the 31st Leeds-Lyon Symposium on Tribology “Life Cycle Tribology”. The University of Leeds, 7–10 September 2004. Tribology and Interface Engineering Series 48, pp. 681–690. Elsevier (2005)Google Scholar
  24. 24.
    Strubel, V., Fillot, N., Ville, F., Cavoret, J., Vergne, P., Mondelin, A., Maheo, Y.: Particle entrapment in rolling element bearings: the effect of ellipticity, nature of materials and sliding. Tribol. Trans. 60(2), 373–382 (2017)CrossRefGoogle Scholar
  25. 25.
    Tropea, C., Yarin, A.L., Foss, J.F.: Springer Handbook of Experimental Fluid Mechanics. Springer, Berlin (2007). ISBN 978-3-540-25141-5CrossRefGoogle Scholar
  26. 26.
    Hamrock, B.J., Dowson, D.: Isothermal elastohydrodynamic lubrication of point contacts: part III-fully flooded results. J. Lubr. Technol. 99(2), 264–275 (1977)CrossRefGoogle Scholar
  27. 27.
    Chevalier, F., Lubrecht, A.A., Cann, P.M.E., Colin, F., Dalmaz, G.: Starvation phenomena in EHL point contacts: influence of inlet flow distribution. In: Dowson, D. et al. (ed.) Proceedings of 22nd Leeds-Lyon Symposium on Tribology “The Third Body Concept: Interpretation of Tribological Phenomena”. Lyon, 5–8 September 1995. Tribology Series 31, pp. 213–223 (1996)Google Scholar
  28. 28.
    Damiens, B., Venner, C.H., Cann, P.M.E., Lubrecht, A.A.: Starved lubrication of elliptical EHD contacts. J. Tribol. 126(1), 105–111 (2004)CrossRefGoogle Scholar
  29. 29.
    Svoboda, P., Kostal, D., Krupka, I., Hartl, M.: Experimental study of starved EHL contacts based on thickness of oil layer in the contact inlet. Tribol. Int. 67, 140–145 (2013)CrossRefGoogle Scholar
  30. 30.
    Kostal, D., Necas, D., Sperka, P., Svoboda, P., Krupka, I., Hartl, M.: Lubricant rupture ratio at elastohydrodynamically lubricated contact outlet. Tribol. Lett. 59(3), 1–9 (2015)CrossRefGoogle Scholar
  31. 31.
    Cann, P.M.E.: Starvation and reflow in a grease-lubricated elastohydrodynamic contact. Tribol. Trans. 39(3), 698–704 (1996)CrossRefGoogle Scholar
  32. 32.
    Cann, P.M.E.: Thin-film grease lubrication. Proc. Inst. Mech. Eng. Part J J. Eng. Tribol. 213(5), 405–416 (1999)CrossRefGoogle Scholar
  33. 33.
    Huang, L., Guo, D., Wen, S., Wan, G.T.Y.: Effects of slide/roll ratio on the behaviours of grease reservoir and film thickness of point contact. Tribol. Lett. 54(3), 263–271 (2014)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2017

Authors and Affiliations

  • V. Strubel
    • 1
  • S. Simoens
    • 2
  • P. Vergne
    • 1
  • N. Fillot
    • 1
  • F. Ville
    • 1
  • M. El Hajem
    • 2
  • N. Devaux
    • 1
  • A. Mondelin
    • 3
  • Y. Maheo
    • 3
  1. 1.Univ Lyon, INSA Lyon, CNRS, LaMCoS UMR5259VilleurbanneFrance
  2. 2.Univ Lyon, EC Lyon, CNRS, LMFA UMR5509ÉcullyFrance
  3. 3.SKF AerospaceChâteauneuf-sur-IsèreFrance

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