The oil consumption of a combustion engine is a result of various consumption mechanisms. Due to optimization towards emission restrictions and low operational costs one basically aims for a self-contained lubricating circuit free from leakage. While static and dynamic seals on rotating shafts and flanges are relatively easy to control, the system piston - piston ring – cylinder liner is influenced by a variety of constructive and process determinated parameters whose interactions are partially opposed. Hence the practical design of piston rings is always a compromise between optimal sealing and the minimization of friction and wear.
Regarding the oil loss of the engine the piston ring package acts as an open system. Due to the tribological necessary lubrication of the cylinder wall during the combustion cycle, a part of the thin oil film evaporates into the cylinder. Together with oil vapor produced by other oil consumption processes, the vaporized lubricating oil is then led into the exhaust system through the exhaust valve and leaves the engine’s lubrication system.
In the course of the project ‘Diesel Oil Emission’ a procedure and the necessary measuring system for crank angle resolved measurement of oil vaporization in the combustion chamber is being developed based on findings from previous research projects on gasoline engines.
For high time resolution measurement of smallest changes in the concentration of long-chain hydrocarbons in the combustion chamber gas, a highly sensitive mass spectrometer is modified using a new ionization method and a CFD-optimized fast direct-inlet system. For system development and testing a single-cylinder research engine and a three-cylinder turbo diesel engine from the Smart compact-car is provided by the project partner.
Project Executing Organisation: Forschungsvereinigung Verbrennungskraftmaschinen (FVV) e.V.
Term: Jan. 2009 - June 2011
