An experimental and theoretical study is presented to study the effect of surface texturing in the form of circumferential oil grooves on improving the tribological properties of piston ring-cylinder liner tribosystem. Tests were performed on a reciprocating test rig with actual piston rings and cylinder liner segments, and a numerical model has been developed. A comparison was made between the performance of the textured cylinder liners and un-textured cylinder liners. It was found that with the smaller oil groove area density, the reduction in friction force is more obvious, Parabolic and triangular oil grooves are more efficient in friction reducing, and the prediction results by numerical model match the experimental results well in most case.

The abnormal wear of diesel engine cylinder often occurs due to the solid particles introduced along with the gas intake, as well as the product of fuel combustion. The main purpose of this research is to develop an unsteady-state liquid–solid model to predict the dynamic and lubrication behaviors of the piston ring-cylinder liner with the consideration of the surface roughness, operating load, material properties, and solid particles. Based on the Reynolds boundary condition, the unsteady-state liquid–solid lubrication model is solved with finite difference method. The accuracy of such model is verified upon the comparison with experimental results from a reciprocating friction test workbench at different working frequencies. The test uses actual piston ring specimens sliding on segments of cylinder liner to simplify the engine operation. Finally, the model is applied for a four-stroke diesel engine to reveal the effects of particle properties. It has found that particle diameter, concentration and yield strength have some significant influences on piston ring-cylinder liner system tribological property.