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Refinement of Engine In-Cycle Losses of Parasitic and Errant Dynamic Nature

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Ring Shape
Conjunctional Geometry
Ring-Bore Conformance: Friction vs Sealing

Ring-bore conformance varies throughout the engine stroke ring traverse as ring loading conditions, speed and temperature change. Additonally the surface of the bore is not a perfect cylinder. Although a seal is formed between the ring and the bore surface a gap is prevalent under some conditions. The ring-bore gap determines the lubricant film thickness, regime of lubrication and ultimately friction.  


The predicted ring bore gap is affected by ring dynamics and thermo-mechanical distorsions of ring and bore,  therefore it is a transient event.




FFT analysis of the measured bore profile