Method for externally controlled availability of lubricating oil in internal combustion engines.

Reduced emissions in internal combustion engines (ICE) are a key component in reaching green-house-gas and pollutive emissions regulations. With increased effort, clean and efficient burning combustion cycles are being developed. With the need of even more efficient engines the friction of ICE engines plays an increasing role in engine efficiency. Also, ingress of lubricating oil into the combustion chamber is a source of particle emissions. Increased optimization to reduce parasitic drag in the piston assembly such as reduced ring pre-tension ore thinner grade oils further increase oil ingress into the combustion chamber with the result of increased particle emissions. The transport mechanisms of oil ingress into the combustion chamber therefore the topic of current research. Specially developed research engines with a vertical optical window have big potentials to visualize phenomena of the oil behavior inside the piston assembly in internal combustion engines. Therefore, these engines play a significant role in identification and uantification of local and global phenomena and their correlating operating parameters. The objective of this study is the development of a device that can be incorporated into the engine that enables control over the amount of oil available in the piston group assembly during varying operating parameters. Ports embedded into the cylinder wall enable access to the ring-land areas for fluid flow out of the piston group assembly using either vacuum or compressed air. The system is tested in a motoredengine condition with opened and closed throttle operation in comparison. The amount of oil present at the piston surface as well as residual oil on the cylinder wall is evaluated. A reduction of up to 40 percent of the indicated LIF-intensity from the residual oil on the cylinder surface can be shown.