A three-dimensional piston ring model has been developed using finite element method with eight-node hexahedral elements. The model predicts the piston ring conformability with the cylinder wall as well as the separation gap between the interfaces if existing in the radial direction. In addition to the radial interaction between the ring front face and the cylinder wall, the model also predicts the contact between the ring and groove sides in the axial direction. This means, the ring axial lift, ring twist, contact forces with the groove sides along the circumferential direction are all calculated simultaneously with the radial conformability prediction. The ring/groove side contact can be found for scraper ring at static condition, which is widely used as the second compression ring in a ring pack.
Thermal load is believed having significant influence on the ring pack performance. This thermal load influence is included in the model with a typical piston ring groove and cylinder wall temperature boundary condition.
The modeling procedure and results are presented in this work. The model analyzes the piston ring performance with the consideration of the variation along the ring circumference, which has not been considered by the two-dimensional models widely used currently.