The Theory of the Surface Wettability Angle in the Formation of an Oil Film in Internal Combustion Piston Engines

In internal combustion piston engines, the formation of an oil film is completely different from that seen in industrial machines. The molecular adhesion force at the interface between the surface coating of engine parts and the lubricating oil determines the load-carrying capacity and the ability to form a lubricated film. The geometry of the lubricating wedge between the surfaces of the piston rings and the cylinder wall is created by the thickness of the oil film and the height of the ring’s coverage with lubricating oil. This condition is affected by many of the parameters that characterize the engine’s operation and the physical and chemical parameters of the coatings used for the cooperating pairs. For lubricant particles that reach energies that are higher than the potential energy barrier regarding adhesive attraction at the interface, slippage occurs. Therefore, the value of the contact angle of the liquid on the surface of the coating depends on the value of the intermolecular force of attraction. According to the current author, there is a strong relationship between the contact angle and the lubrication effect. The paper shows that the surface potential energy barrier is a function of the contact angle and contact angle hysteresis (CAH). The innovation of the current work consists in examining the contact angle and CAH under the conditions of thin layers of lubricating oil, in cooperation with hydrophilic and hydrophobic coatings. The thickness of the lubricant film was measured under various speed and load conditions, using optical interferometry. The study shows that CAH is a better interfacial parameter for correlation with the effect of hydrodynamic lubrication. This paper presents the mathematical relationships relating to a piston engine, various coatings, and lubricants.

[1]  P. Wróblewski.  Investigation of Energy Losses of the Internal Combustion Engine Taking into Account the Correlation of the Hydrophobic and Hydrophilic , 2022, SSRN Electronic Journal.

[2]  P. Wróblewski,et al.  Experimental Analysis of the Influence of the Application of TiN, TiAlN, CrN and DLC1 Coatings on the Friction Losses in an Aviation Internal Combustion Engine Intended for the Propulsion of Ultralight Aircraft , 2021, Materials.

[3]  P. Wróblewski,et al.  An Experimental Study on Frictional Losses of Coated Piston Rings with Symmetric and Asymmetric Geometry , 2021 .

[4]  A. Iskra,et al.  Problems of Reducing Friction Losses of a Piston-Ring-Cylinder Configuration in a Combustion Piston Engine with an Increased Isochoric Pressure Gain , 2020 .

[5]  K. Vasilev,et al.  Questions and Answers on the Wettability of Nano‐Engineered Surfaces , 2017 .

[6]  Jin-Goo Park,et al.  Preparation of a high hydrophobic aluminium surface by double zincating process , 2017 .

[7]  P. Wong,et al.  Identifying the optimal interfacial parameter correlated with hydrodynamic lubrication , 2016 .

[8]  G. Sreenivasulu,et al.  Poly (vinylidene fluoride) / Poly (acrylonitrile)-based Superior Hydrophobic Piezoelectric Solid Derived by Aligned Carbon Nanotube in Electrospinning: Fabrication, the Phase Conversion and Surface Energy. , 2015, RSC advances.

[9]  P. Wong,et al.  Experimental Study on Lubrication Film Thickness Under Different Interface Wettabilities , 2014, Tribology Letters.

[10]  R. Kovacevic,et al.  Wettability characterization and adhesion enhancement of arc-treated surface of aluminum alloys , 2014 .

[11]  H. B. Eral,et al.  Contact angle hysteresis: a review of fundamentals and applications , 2013, Colloid and Polymer Science.

[12]  P. Wong,et al.  Effect of Interfacial Properties on EHL Under Pure Sliding Conditions , 2012, Tribology Letters.

[13]  Hooshang Heshmat,et al.  Load Capacity and Durability of H-DLC Coated Hydrodynamic Thrust Bearings , 2011 .

[14]  Yi Y. Zuo,et al.  Applied Surface Thermodynamics , 2010 .

[15]  P. L. Wong,et al.  Interferometry Measurement of Lubricating Films in Slider-On-Disc Contacts , 2010 .

[16]  Jože Vižintin,et al.  The Stribeck curve and lubrication design for non-fully wetted surfaces , 2009 .

[17]  D. Bonn,et al.  Wetting and Spreading , 2009 .

[18]  J. D. Cogdell,et al.  Traction of Lubricated Rolling Contacts between Thin-Film Coatings and Steel , 2008 .

[19]  R. Netz,et al.  Water slippage versus contact angle: a quasiuniversal relationship. , 2008, Physical review letters.

[20]  Gang Li,et al.  Effect of surface physicochemical properties on the lubricating properties of water film , 2008 .

[21]  B. Bhushan,et al.  Nanorheology and boundary slip in confined liquids using atomic force microscopy , 2008 .

[22]  Olivier Raccurt,et al.  Nanohydrodynamics: the intrinsic flow boundary condition on smooth surfaces. , 2008, Langmuir : the ACS journal of surfaces and colloids.

[23]  Edward Bormashenko,et al.  The rigorous derivation of Young, Cassie–Baxter and Wenzel equations and the analysis of the contact angle hysteresis phenomenon , 2008 .

[24]  Jason R. Stokes,et al.  Soft-tribology : Lubrication in a compliant PDMS-PDMS contact , 2007 .

[25]  J. Hyväluoma,et al.  Droplets on inclined rough surfaces , 2007, The European physical journal. E, Soft matter.

[26]  Chengwei Wu,et al.  Multi‐linearity algorithm for wall slip in two‐dimensional gap flow , 2007 .

[27]  H. Spikes,et al.  Friction reduction in low-load hydrodynamic lubrication with a hydrophobic surface , 2007 .

[28]  Hugh Spikes,et al.  A Low Friction Bearing Based on Liquid Slip at the Wall , 2006 .

[29]  F. Rieutord,et al.  Dipole-dependent slip of Newtonian liquids at smooth solid hydrophobic surfaces. , 2004, Physical review letters.

[30]  C. Extrand,et al.  Contact angles and their hysteresis as a measure of liquid-solid adhesion. , 2004, Langmuir : the ACS journal of surfaces and colloids.

[31]  Hugh Spikes,et al.  Equation for Slip of Simple Liquids at Smooth Solid Surfaces , 2003 .

[32]  Andreas Opitz,et al.  The effect of wetting on the microhydrodynamics of surfaces lubricated with water and oil , 2003 .

[33]  Hans-Jürgen Butt,et al.  Surface roughness and hydrodynamic boundary slip of a newtonian fluid in a completely wetting system. , 2003, Physical review letters.

[34]  H. Spikes.  The half-wetted bearing. Part 1: Extended Reynolds equation , 2003 .

[35]  P. L. Wong,et al.  A multi-beam intensity-based approach for lubricant film measurements in non-conformal contacts , 2002 .

[36]  C. Meinhart,et al.  Apparent fluid slip at hydrophobic microchannel walls , 2002 .

[37]  Hans-Jürgen Butt,et al.  Hydrodynamic force measurements: boundary slip of water on hydrophilic surfaces and electrokinetic effects. , 2002, Physical review letters.

[38]  S. Granick,et al.  Rate-dependent slip of Newtonian liquid at smooth surfaces. , 2001, Physical review letters.

[39]  J. Baudry,et al.  Experimental Evidence for a Large Slip Effect at a Nonwetting Fluid−Solid Interface , 2001 .

[40]  Daniel Y. Kwok,et al.  Contact angle measurement and contact angle interpretation , 1999 .

[41]  Lydéric Bocquet,et al.  Large Slip Effect at a Nonwetting Fluid-Solid Interface , 1999 .

[42]  O. Vinogradova.  Slippage of water over hydrophobic surfaces , 1999 .

[43]  Olga I. Vinogradova,et al.  Drainage of a Thin Liquid Film Confined between Hydrophobic Surfaces , 1995 .

[44]  Dongqing Li,et al.  EQUATION OF STATE FOR INTERFACIAL TENSIONS OF SOLID-LIQUID SYSTEMS , 1992 .

[45]  Dongqing Li,et al.  Contact angles on hydrophobic solid surfaces and their interpretation , 1992 .

[46]  M. Chaudhury,et al.  Interfacial Lifshitz-van der Waals and polar interactions in macroscopic systems , 1988 .

[47]  S. G. Mason,et al.  An experimental study of some effects of solid surface roughness on wetting , 1980 .

[48]  R. Good.  Contact Angles and the Surface Free Energy of Solids , 1979 .

[49]  A. Neumann,et al.  An equation-of-state approach to determine surface tensions of low-energy solids from contact angles , 1974 .

[50]  R. H. Dettre,et al.  Contact Angle Hysteresis. IV. Contact Angle Measurements on Heterogeneous Surfaces1 , 1965 .

[51]  W. Zisman,et al.  Contact angle, wettability, and adhesion , 1964 .