Modelling and analysis of slip conditions in hydrodynamic lubrication of a piston skirt-cylinder contact Mustapha Mechalikh Faculty of Technology, Rheology and Mechanics Laboratory, Hassiba Benbouali University of Chlef, Chlef, Algeria Ibrahim Zidane Department of Mechanical Engineering, Faculty of Technology, Rheology and Mechanics Laboratory, Hassiba Benbouali University of Chlef, Chlef, Algeria Abdessoufi Benhamou Faculty of Technology, Mechanics and Energy Laboratory, Hassiba Benbouali University of Chlef, Chlef, Algeria Hamid Zaidi Department of Mechanical Engineering, Pprime Institute, University of Poitiers, Poitiers, France, and Miloud Tahar Abbes Faculty of Technology, Mechanics and Energy Laboratory, Hassiba Benbouali University of Chlef, Chlef, Algeria Abstract Purpose – After more than a century of agreement with the postulate of non-slip condition (adhesion to the wall), the study of ﬂuid-solid boundary conditions has shown renewed interest over the past two decades. Although numerous studies have not yet been arrived to a complete description of slip phenomena, however, it appears that the inﬂuence of wetting and/or surface roughness results in a weak interaction between ﬂuid and solid; thus, the presence of the slip phenomenon is observed at the ﬂuid-solid interface. The purpose of this paper is to highlight the presence of the slip phenomenon at the lubricated piston skirt- cylinder contact. Design/methodology/approach – For this proposal, a modiﬁed Reynolds equation and operating characteristics are determined by taking into account the slip conditions at the interface between oil-ﬁlm and entire cylinder surface. Findings – The ﬁndings indicate that the operating characteristics are strongly inﬂuenced when the slip conditions are taken into account at the interface between oil-ﬁlm and cylinder surface. The friction force and dissipated power might be reduced to improve diesel engine performances. Originality/value – Various research studies have been conducted to model the slip phenomenon in different lubricated contacts over the past two decades. However, there are no studies available concerning the piston-cylinder system. Peer review – The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2019-0483/ Keywords Hydrodynamic lubrication, Boundary lubrication, Piston skirt-cylinder contact, Slip/no-slip conditions Paper type Research paper Nomenclature A = dimensionless slip coefﬁcient (A = ah /c); B = dimensionless piston radius (B = R/L); b = slip length, m m; c = radial clearance, m m; E b ,E h = dimensionless top and bottom skirt eccentricities (E b =e b /C and E h =e h /C); e b ,e h = top and bottom skirt eccentricities (distance between the centre at the top and the bottom of the skirt and the cylinder axis, respectively), m m; F – f = dimensionless frictional force ( F f = C.F f /2p RW 1 ); F f = frictional force, N; H = dimensionless ﬂuid-ﬁlm thickness (H = h/c); h = ﬂuid-ﬁlm thickness, m m; L = piston skirt length, m; ‘ = conrod length, m; O xyz = Cartesian coordinate system; P = dimensionless pressure (P = pc 2 / h W 1 R); p = hydrodynamic pressure, Pa; Pu = dissipated power (Pu =|F f |U), Watt; Q z = ﬂow rate, m 3 /s; The current issue and full text archive of this journal is available on Emerald Insight at: https://www.emerald.com/insight/0036-8792.htm Industrial Lubrication and Tribology © Emerald Publishing Limited [ISSN 0036-8792] [DOI 10.1108/ILT-11-2019-0483] This research was supported by the Ministry of Higher Education and Scientiﬁc Research and the Directorate General for Scientiﬁc Research and Technological Development of Algeria. Received 13 November 2019 Revised 17 February 2020 11 April 2020 Accepted 12 April 2020