A Generic Simulation Model for Cylinder Kit Vibro-Acoustics: Part I — Piston Slap in Mixed Lubrication Regime

Precise models for the numerical simulation of contacting engine parts cause conflicting demands in efficiency and accuracy. This is particularly valid for the cylinder kit of combustion engines. Here impacts of piston and liner surfaces via the oil film effect friction, wear and vibro-acoustic excitation. As the first of parts, this contribution describes a mixed lubrication model for the cylinder kit considering effects of mass, elasticity, surface roughness and hydrodynamics. The model is used to predict the impact between piston and liner and the resulting vibration excitation near FTDC of a running four cylinder diesel engine. The calculated results are validated by means of measurements. The significant effects of specific model parameters are discussed, e.g. oil filling between running shapes of the contacting structures.