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Effect of Film Thickness on Slip and Traction Performances in Elastohydrodynamic Lubrication by a Molecular Dynamics Simulation

Abstract

The nonequilibrium molecular dynamics simulations were carried out to study the slip and traction properties of a traction fluid with effect of film thickness, under high-temperature and -pressure conditions. The thinnest film of about 14 Å presents a solid-like structure which shows a two-layer discrete distribution. The film of about 24 Å corresponds to the intermediate state between the solid-like and liquid phases. With the increasing film thickness, a continuous bulk structure confined by solid-like phases appears in the central region, leading to relatively loose interlayer structure. The velocity profile across the film was then analyzed to obtain the shear property. It indicates that the thinnest film shows a plug-slip shear, the relatively thick films show a shear localization, and the thickest film of about 86 Å shows a stick–slip phenomenon. The slip length increases and then reaches the maximum as the film thickness increases to 63 Å, which is related to the change of solid-like phase near the inner surface of slab. Finally, the traction coefficient illustrates the locally lowest value of 0.08 in the moderate film of 42 Å while the highest value is reached in the two-layer system. The inverse proportion relationship between slip length and traction coefficient is obtained. This study is helpful to understand the flow and traction characteristics and their relationship in elastohydrodynamic lubricant for the important use in new infinitely variable transmission systems.

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References

  1. 1.

    Nilabh, S., Imtiaz, H.: A review on belt and chain continuously variable transmissions (CVT): dynamics and control. Mech. Mach. Theory 44(1), 19–41 (2009)

    Google Scholar 

  2. 2.

    Ruan, J.G., Walker, P., Zhang, N.: A comparative study energy consumption and costs of battery electric vehicle transmissions. Appl. Energ. 165, 119–134 (2016)

    Google Scholar 

  3. 3.

    Webster, M.N., Lee, G.H., Chang, L.: Effect of EHL contact conditions on the behavior of traction fluids. Tribol. Trans. 49(3), 439–448 (2006)

    CAS  Google Scholar 

  4. 4.

    Gattinoni, C., Heyes, D.M., Lorenz, C.D., Dini, D.: Traction and nonequilibrium phase behavior of confined sheared liquids at high pressure. Phys. Rev. E 88(5), 052406 (2013)

    Google Scholar 

  5. 5.

    Tsubouchi, T., Abe, K., Hat, H.: Quantitative correlation between molecular structures of traction fluids and their traction properties (part 1): influence of alkylene chain. Jpn. J. Tribol. 38, 403–410 (1993)

    Google Scholar 

  6. 6.

    Tsubouchi, T., Abe, K., Hata, H.: Quantitative correlation between molecular structures of traction fluids and their traction properties (part 2): precise investigation into the molecular stiffness. Jpn. J. Tribol. 39, 373–381 (1994)

    Google Scholar 

  7. 7.

    Ewen, J.P., Gao, H.Y., Martin, M.H., Daniele, D.: Shear heating, flow, and friction of confined molecular fluids at high pressure. Phys. Chem. Chem. Phys. 21(10), 5813–5823 (2019)

    CAS  Google Scholar 

  8. 8.

    Desanker, M., He, X.L., Lu, J., Liu, P.Z., Pickens, D.B., Delferro, M., Marks, T.J., Chung, Y.W., Wang, Q.J.: Alkyl-cyclens as effective sulfur- and phosphorus-free friction modifiers for boundary lubrication. ACS Appl. Mater. Interfaces 9(10), 9118–9125 (2017)

    CAS  Google Scholar 

  9. 9.

    Lu, X., Khonsari, M., Gelinck, E.: The Stribeck curve: experimental results and theoretical prediction. J. Tribol. 128(4), 789–794 (2006)

    Google Scholar 

  10. 10.

    Granick, S.: Motions and relaxations of confined liquids. Science 253(5026), 1374–1379 (1991)

    CAS  Google Scholar 

  11. 11.

    Washizu, H., Ohmori, T.: Molecular dynamics simulations of elastohydrodynamic lubrication oil film. Lubr. Sci. 22(8), 323–340 (2010)

    CAS  Google Scholar 

  12. 12.

    Neto, C., Evans, D.R., Bonaccurso, E., Butt, H., Craig, V.S.J.: Boundary slip in newtonian liquids: a review of experimental studies. Rep. Prog. Phys. 68(12), 2859–2897 (2005)

    CAS  Google Scholar 

  13. 13.

    Wu, W., Liu, J.X., Li, Z.H., Zhao, X.Y., Liu, G.Q., Liu, S.J., Ma, S.H., Li, W.M., Liu, W.M.: Surface-functionalized nano MOFs in oil for friction and wear reduction and antioxidation. Chem. Eng. J. 410, 128306 (2021)

    CAS  Google Scholar 

  14. 14.

    Gupta, S.A., Cochran, H.D., Cummings, P.T.: Shear behavior of squalane and tetracosane under extreme confinement. I. Model, simulation method, and interfacial slip. J. Chem. Phys. 107(23), 10316–10326 (1997)

    CAS  Google Scholar 

  15. 15.

    Jabbarzadeh, A., Atkinson, J.D., Tanner, R.I.: Wall slip in the molecular dynamics simulation of thin films of hexadecane. J. Chem. Phys. 110, 2612–2620 (1999)

    CAS  Google Scholar 

  16. 16.

    Ta, D.T., Tieu, A.K., Zhu, H.T., Kosasih, B.: Thin film lubrication of hexadecane confined by iron and iron oxide surfaces: a crucial role of surface structure. J. Chem. Phys. 143(16), 164702 (2015)

    CAS  Google Scholar 

  17. 17.

    Fillot, N., Berro, H., Vergne, P.: From continuous to molecular scale in modelling elastohydrodynamic lubrication nanoscale surface slip effects on film thickness and friction. Tribol. Lett. 43, 257–266 (2011)

    CAS  Google Scholar 

  18. 18.

    Habchi, W., Vergne, P., Eyheramendy, D., Morales-Espejel, G.E.: Numerical investigation of the use of machinery low-viscosity working fluids as lubricants in elastohydrodynamic lubricated point contacts. Proc. Inst. Mech. Eng. 225(6), 465–477 (2011)

    Google Scholar 

  19. 19.

    Zhang, Y.G., Wang, W.Z., Liang, H., Zhao, Z.Q.: Layered oil slip model for investigation of film thickness behaviours at high speed conditions. Tribol. Int. 131, 137–147 (2019)

    Google Scholar 

  20. 20.

    Heyes, D.M., Smith, E.R., Dini, D., Spikes, H.A., Zaki, T.A.: Pressure dependence of confined liquid behavior subjected to boundary-driven shear. J. Chem. Phys. 136(13), 134705 (2012)

    CAS  Google Scholar 

  21. 21.

    Fernandes, C., Marques, P., Martins, R.C., Seabra, J.: Film thickness and traction curves of wind turbine gear oils. Tribol. Int. 86, 1–9 (2015)

    Google Scholar 

  22. 22.

    Ewen, J.P., Gattinoni, C., Zhang, J., Heyes, D.M., Spikes, H.A., Dini, D.: On the effect of confined fluid molecular structure on nonequilibrium phase behaviour and friction. Phys. Chem. Chem. Phys. 19(27), 17883–17894 (2017)

    CAS  Google Scholar 

  23. 23.

    Liu, H.C., Zhang, B.B., Bader, N., Venner, C.H., Poll, G.: Scale and contact geometry effects on friction in thermal EHL: twin-disc versus ball-on-disc. Tribol. Int. 154, 106694 (2021)

    Google Scholar 

  24. 24.

    Lu, J., Wang, Q.J., Ren, N., Lockwood, F.E.: Correlation between pressure-viscosity coefficient and traction coefficient of the base stocks in traction lubricants: a molecular dynamic approach. Tribol. Int. 134, 328–334 (2019)

    Google Scholar 

  25. 25.

    Dauber-Osguthorpe, P., Roberts, V.A., Osguthorpe, D.J., Wolff, J., Genest, M., Hagler, A.T.: Structure and energetics of ligand binding to proteins: Escherichia coli dihydrofolate reductase-trimethoprim, a drug-receptor system. Proteins 4(1), 31–47 (1988)

    CAS  Google Scholar 

  26. 26.

    Shi, J.Q., Zhang, M., Liu, J.X., Liu, G.Q., Zhou, F.: Molecular dynamics simulations of adsorption behavior of organic friction modifiers on hydrophilic silica surfaces under the effects of surface coverage and contact pressure. Tribol. Int. 156, 106826 (2021)

    CAS  Google Scholar 

  27. 27.

    Shi, J.Q., Zhou, Q., Sun, K., Liu, G.Q., Zhou, F.: Understanding adsorption behaviors of organic friction modifiers on hydroxylated sio2 (001) surfaces: effects of molecular polarity and temperature. Langmuir 36(29), 8543–8553 (2020)

    CAS  Google Scholar 

  28. 28.

    Huang, D., Zhang, T., Xiong, G., Xu, L., Qu, Z., Lee, E., Luo, T.: Tuning water slip behavior in nanochannels using self-assembled monolayers. ACS Appl. Mater. Interfaces 11(35), 32481–32488 (2019)

    CAS  Google Scholar 

  29. 29.

    Martini, A., Hsu, H.Y., Patankar, N.A., Lichter, S.: Slip at high shear rates. Phys. Rev. Lett. 100(20), 206001 (2008)

    Google Scholar 

  30. 30.

    Dushanov, E., Kholmurodov, K., Yasuoka, K.: Molecular dynamics studies of the interaction between water and oxide surfaces. Phys. Part. Nucl. Lett. 9(6–7), 541–551 (2012)

    CAS  Google Scholar 

  31. 31.

    Plimpton, S.: Fast parallel algorithms for short-range molecular dynamics. J. Comput. Phys. 117, 1–19 (1995)

    CAS  Google Scholar 

  32. 32.

    Evans, D.J., Lee, H.B.: The Nose–Hoover thermostat. J. Chem. Phys. 83(8), 4069–4074 (1985)

    CAS  Google Scholar 

  33. 33.

    Hata, H., Tsubouchi, T.: Molecular structures of traction fluids in relation to traction properties. Tribol. Lett. 5, 69–74 (1998)

    CAS  Google Scholar 

  34. 34.

    Porras-Vazquez, A., Martinie, L., Vergne, P., Fillot, N.: Independence between friction and velocity distribution in fluids subjected to severe shearing and confinement. Phys. Chem. Chem. Phys. 20(43), 27280–27293 (2018)

    CAS  Google Scholar 

  35. 35.

    Stukowski, A.: Visualization and analysis of atomistic simulation data with OVITO–the open visualization tool. Model. Simul. Mater. Sci. Eng. 18(1), 015012 (2010)

    Google Scholar 

  36. 36.

    Ewen, J.P., Kannam, S.K., Todd, B.D., Dini, D.: Slip of alkanes confined between surfactant monolayers adsorbed on solid surfaces. Langmuir 34(13), 3864–3873 (2018)

    CAS  Google Scholar 

  37. 37.

    Klein, J., Kumacheva, E.: Simple liquids confined to molecularly thin layers. I. Confinement-induced liquid-to-solid phase transitions. J. Chem. Phys. 108(16), 6996–7009 (1998)

    CAS  Google Scholar 

  38. 38.

    Gao, H., Müser, M.H.: Why liquids can appear to solidify during squeeze-out–Even when they don’t. J. Colloid Interface Sci. 562, 273–278 (2020)

    CAS  Google Scholar 

  39. 39.

    Wang, S., Javadpour, F., Feng, Q.: Molecular dynamics simulations of oil transport through inorganic nanopores in shale. Fuel 171, 74–86 (2016)

    CAS  Google Scholar 

  40. 40.

    Omori, T., et al.: Full characterization of the hydrodynamic boundary condition at the atomic. Phys. Rev. Fluids 4, 114201 (2019)

    Google Scholar 

  41. 41.

    Maćkowiak, S.Z., Heyes, D.M., Dini, D., Brańka, A.C.: Non-equilibrium phase behavior and friction of confined molecular film under shear: a nonequilibrium molecular dynamics study. J. Chem. Phys. 145, 164704 (2016)

    Google Scholar 

  42. 42.

    Echeverri, R.S., Marcel, C.P., Ewen, J.P.: Behaviour of n-alkanes confined between iron oxide surfaces at high pressure and shear rate: a nonequilibrium molecular dynamics study. Tribol. Int. 137, 420–432 (2019)

    Google Scholar 

  43. 43.

    Yong, X., Zhang, L.T.: Thermostats and thermostat strategies for molecular dynamics simulations of nanofluidics. J. Chem. Phys. 138(8), 084503 (2013)

    Google Scholar 

  44. 44.

    Bernardi, S., Todd, B., Searles, D.J.: Thermostating highly confined fluids. J. Chem. Phys. 132(24), 244706 (2010)

    Google Scholar 

  45. 45.

    Khare, R., Pablo, J.D., Yethiraj, A.: Molecular simulation and continuum mechanics study of simple fluids in non-isothermal planar couette flows. J. Chem. Phys. 107(7), 2589–2596 (1997)

    CAS  Google Scholar 

  46. 46.

    Sharif, K.J., Evans, H.P., Snidle, R.W., Newall, J.P.: Modeling of film thickness and traction in a variable ratio traction drive rig. Trans. ASME 126, 92–104 (2004)

    CAS  Google Scholar 

  47. 47.

    Koshun, O., Haruki, O., Hiroki, K., Yasutaka, Y., Takeshi, O., Samy, M., Laurent, J.: Large effect of lateral box size in molecular dynamics simulations of liquid-solid friction. Phys. Rev. E 100(023101), 1–8 (2019)

    Google Scholar 

  48. 48.

    Itagaki, H., Ohama, K., Rajan, A.N.R.: Method for estimating traction curves under practical operating conditions. Tribol. Int. 149, 105639 (2020)

    Google Scholar 

  49. 49.

    Gao, J., Luedtke, W., Landman, U.: Structures, solvation forces and shear of molecular films in a rough nano-confinement. Tribol. Lett. 9(1), 3–13 (2000)

    CAS  Google Scholar 

  50. 50.

    Ree, T., Eyring, H.: Theory of non-newtonian flow. I. Solid plastic system. J. Chem. Phys. 26(7), 793–800 (1955)

    CAS  Google Scholar 

Download references

Acknowledgements

The authors acknowledge the financial support from the Fundamental Research Funds for the Central Universities, Natural Science Basic Research Program of Shaanxi (Program No. 2021JQ-116), and the Research Fund of the State Key Laboratory of Solidification Processing (NPU), China (Grant No. 2021-TS-06).

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Correspondence to Xiaoli Fan.

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Shi, J., Wang, J., Yi, X. et al. Effect of Film Thickness on Slip and Traction Performances in Elastohydrodynamic Lubrication by a Molecular Dynamics Simulation. Tribol Lett 69, 141 (2021). https://doi.org/10.1007/s11249-021-01516-9

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Keywords

  • Traction performance
  • Slip property
  • Elastohydrodynamic lubrication
  • Molecular dynamics simulation