Noise and vibrations from an engine form important benchmarks from customer satisfaction view while choosing an automotive car. There are several sources of noise and vibrations emissions from an engine installed in a car. Some of these sources include: combustion noise, exhaust flow noise, aero dynamic noise as well as noise due to mechanical motion of parts etc. Each of these sources of noise depends on some factors which includes fuel injection parameters, design of engine, lubrication regime, operational parameters like speed and load. Motion of piston skirt form a major source of noise and vibrations in an automotive car. Apart from normal reciprocating motion of skirt, there can be secondary motion along the lateral direction. This motion is known as piston slapping motion. There are several factors that affect this lateral motion of skirt which includes the design of piston, type of lubrication as well as the speed of engine. In the present work a numerical model of lateral motion of skirt has been proposed. The proposed model was applied for a dual cylinder water cooled diesel engine. Effects of various design parameters like piston-liner clearance, skirt length, mass of skirt, and location of piston pin has been analyzed. The proposed methodology can be used to optimize the design of skirt in order to reduce the noise and vibration emissions arising due to lateral striking motion of skirt with liner.
