Simulation of deposits effect on cylinder liner and influence on new and worn compression ring of a turbocharged DI engine

Abstract Engineers and engine manufactures have known for years that piston rings account as the main source of the friction in internal combustion engines, as much as seventy-five percent in many cases. Excessive engine wear is also, very often caused by poor vehicle operation, and subsequent momentary poor lubrication. The paper presents a numerical methodology and results regarding the wear and deposition effects on an internal combustion engine piston rings as a result of engine lubrication. The deposits can lead to increment of oil consumption and emissions, reducing engine performance and fuel economy. A 2D CFD approach was implemented in order to investigate the characteristics of the top compression ring deposit formation in a diesel engine. The developed pressures, the friction force and the minimum film thickness have been investigated. The variation of the minimum film thickness for new and worn rings at piston reversals, the insufficient minimum film thickness, the thicker films of the increment of the engine speed appeared at worn ring profile in the middle of each stroke, corresponds to a worst sealing behavior due to deposit, are some of major findings of this work. The deposits investigation and hence the paper importance is crucial in combustion engines operation as well as it can covers both axial turbines and their cooling at preliminary design phase.