Combined measurement and simulation of piston ring cylinder liner contacts with a reciprocating long-stroke tribometer

One approach to decrease emissions and improve the efficiency of combustion engines is reducing friction losses, especially in the interface between piston ring and cylinder liner. Usual model-like tribometer tests cover piston ring cylinder liner operating conditions at reversal points. This study introduces an innovative method using a new reciprocating long-stroke tribometer at component level as well as a new elastohydrodynamic simulation model enabling a greater range of operating conditions through higher velocities. The process of friction data evaluation is clarified studying crank angle resolved friction data and the effect of viscous properties is tested. The simulation allows investigating the local nominal gap height and the division of the pressure in its hydrodynamic and asperity contact contributions in detail. The results show that this combined tribological testing method obtains a quantifiable distinction between the investigated tribological systems. Additionally, a high correlation between measured friction results and simulation is achieved in general, which prospectively allows further investigations and parameter studies of reciprocating contacts.