Transverse Movement Analysis and Its Influence on Diesel Piston Design

The latest advances made in the development in a theoretical analysis of piston movement are described, covering the introduction of such new features as non-parallel bores, ring/groove friction, conservation of angular momentum at impact, and kinetic energy loss at impact. A single value of friction co-efficient of 0.2″ is derived from experimental data and the new program is shown to give good agreement with measured piston movement traces.

The movement program is used to examine several piston design features in respect of their influence on impact severity and indicates the importance of gudgeon pin offset, piston/liner clearance and gudgeon pin height when considering piston noise.

Further study on the features of friction and impact conditions are suggested, and the work is seen to have wider implications in the development of a complete set of piston assembly predictive design techniques.