Computational Study on the Frictional Power Loss Reduction of Piston Ring with Laser Surface Texturing on the Cylinder Liner.

—Hydrodynamic lubrication is simulated under the contact conditions that the direction of contact velocity reverses with a sudden high applied load in the contact of piston top ring and cylinder liner. Hydrodynamic lubrication film formation and pressure between piston ring and cylinder liner at the top dead center (TDC) location are investigated in detail because most friction loss and wear damage happen at this location due to the thin-film thickness resulting from the slow-down and reversal contact velocities as well as high applied load. The surface roughness on the cylinder liner by the honing process that is similar scale to the lubrication film thickness at TDC location is considered. Around the TDC location, laser surface textured (LST) surface that is larger scale than the surface roughness is designed for the favorable film formation. These two surface roughness parameters are simulated to study the effects of favorable film formation and less frictional loss of piston top ring at TDC location where most of damage and friction loss occur. Frictional power loss and minimum film thickness of the cylinder surfaces of the honed roughness are compared with those of patterned designs. [ABSTRACT FROM AUTHOR]