A Numerical Model to Study the Role of Surface Textures at Top Dead Center Reversal in the Piston Ring to Cylinder Liner Contact
| Autor: | Homer Rahnejat, S.J. Howell-Smith, Ramin Rahmani, Paul King, Nicholas J. Morris |
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| Rok vydání: | 2015 |
| Předmět: |
Engineering
business.industry Mechanical Engineering Mechanical engineering 02 engineering and technology Surfaces and Interfaces Surface finish Tribology 021001 nanoscience & nanotechnology Reynolds equation Surfaces Coatings and Films Cylinder (engine) law.invention Piston 020303 mechanical engineering & transports 0203 mechanical engineering Internal combustion engine Mechanics of Materials law Lubrication Piston ring 0210 nano-technology business |
| Zdroj: | Journal of Tribology. 138 |
| ISSN: | 1528-8897 0742-4787 |
| Popis: | Minimization of parasitic losses in the internal combustion (IC) engine is essential for improved fuel efficiency and reduced emissions. Surface texturing has emerged as a method palliating these losses in instances where thin lubricant films lead to mixed or boundary regimes of lubrication. Such thin films are prevalent in contact of compression ring to cylinder liner at piston motion reversals because of momentary cessation of entraining motion. The paper provides combined solution of Reynolds equation, boundary interactions, and a gas flow model to predict the tribological conditions, particularly at piston reversals. This model is then validated against measurements using a floating liner for determination of in situ friction of an engine under motored condition. Very good agreement is obtained. The validated model is then used to ascertain the effect of surface texturing of the liner surface during reversals. Therefore, the paper is a combined study of numerical predictions and the effect of surface texturing. The predictions show that some marginal gains in engine performance can be expected with laser textured chevron features of shallow depth under certain operating conditions. |
| Databáze: | OpenAIRE |
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