Curved Beam Based Model for Piston-Ring Designs in Internal Combustion Engines: Working Engine Conditions Study

A new multi-scale curved beam based model was developed for piston-ring designs. This tool is able to characterize the behavior of a ring with any cross section design. This paper describes the conformability and ring static twist calculation. The conformability part model the static behavior of the ring in working engine conditions. The model employs the computation scheme that separates the meshing of the structure and local force generation. Additional to the conventional static ring-bore conformability analysis, the conformability model is designed to examine ring-bore and ring-groove interactions in a running engine under varying driving forces and localized lubrication conditions. We made Improvements on the way to handle the effects of the radial temperature gradient compared to the existing models. Examples are given on the effects of ring rotation on the interaction of the ring and a distorted bore as well as the change of local lubrication conditions. Ring static twist calculation was also included to provide necessary input for 2D models. The present model can become a viable ring design tool revealing not only static ring behavior but also the distribution of the clearance and force between ring and bore as well as groove under the dynamic situation of an engine cycle.