Tribology of piston compression ring conjunction under transient thermal mixed regime of lubrication Nick Morris Ramin Rahmani Homer Rahnejat Paul King Brian Fitzsimons 2134/11868 https://repository.lboro.ac.uk/articles/journal_contribution/Tribology_of_piston_compression_ring_conjunction_under_transient_thermal_mixed_regime_of_lubrication/9569912 Fuel efficiency is the main IC engine attribute, with the compression ring-bore contact consuming nearly 5% of the fuel energy. Analyses are often idealised, such as isothermal condition and smooth surfaces, the former being particularly contrary to practice. An analytic solution to the average flow model is presented for this contact with a new analytical thermal model. The generated contact temperatures, particularly at the inlet result in thinner films than the idealised analyses. For the simulated city driving condition the power loss is mainly due to viscous shear under cold engine condition, whilst for a hot engine boundary friction dominates. 2013-03-06 14:37:57 Piston ring Mixed lubrication Friction Heat Mechanical Engineering not elsewhere classified Mechanical Engineering