Engine NVH issues: piston slap modelling and sensitivity to piston-pin offset
What is it about?
Piston slap can be a very important NVH issue in internal combustion engines, expecially in high performance ones, as the lateral force transmitted to the cylinder liner can be truly relevant because of the high pressure reached in the combustion chamber. This paper compares an analytical method to assess the lateral force with a much more detailed multibody approach. The latter provides an accurate modelling of the contacting surfaces and piston lateral motion, allowing to clearly identify the piston slap events.
Why is it important?
The main finding of the work is the indentification of piston slap events and their great sensibility to the piston pin offset, the distribution of the pressure on the piston top surface and the radial gap between piston and liner. This gap can be accurately determined through a thermostructural analysis of the portion of the engine block surrounding the cylinder. The correlation between the piston rotation/inclination in the plane of motion (influenced by the previously mentioned factors) and the piston slap occurrences is clearly highlighted.
The following have contributed to this page: Matteo Cavalli
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