RINGPAK - ring dynamics

RINGPAK uses axis-symmetric assumptions to simulate twist, and axial and radial motions of separate rings on the piston assembly. In addition, effects of surrounding gas pressure, boundary lubrication, hydrodynamic lubrication, system friction and inertia are also considered in force and momentum balances.

Sealing calculations can be performed that are based on detailed gas-flow analysis through the ring pack. From these studies, blow-by and blow-back values can be predicted. Using this methodology, RINGPAK forms an interconnected system of gas volumes. The gas flow between these volumes is controlled by the ring motion or by the conformability of the rings to the liner body during deformation.

RINGPAK includes two flow models, one based on isentropic conditions and the other on compressible isothermal flow. Each flow model can be selected explicitly or RINGPAK can calculate the best solution based on flow parameters.

Key features

• Axis-symmetric 2D treatment, including 3D features for bore distortion, ring conformability, crown shape and crown thermal distortion
• Mass-conserving hydrodynamic lubrication model
• Boundary lubrication model
• Channel flow and orifice flow inter-ring gas dynamics
• Ring-liner conformability
• Different oil supply modes