Optimization of the surface texture on piston ring in four-stroke IC engine

Abstract

In the automobile industry, the fuel efficiency of the internal combustion (IC) engine is an essential parameter. In the IC engine, the piston ring-cylinder liner pair is the largest source of frictional losses and engine oil consumption. It accounts for 50% of the total losses; therefore, it is paramount to optimize this contact for improving efficiency. Different new materials, coatings, and nano-materials, and surface texturing are few prominent techniques available for minimizing parasitic losses in the IC engine, in which surface-texturing is considered as eco-friendly and green technology. Surface texturing is being widely used in improving performance parameters in the IC engine. Therefore, in this study, the optimization of two different surface textures is performed. In the numerical model, the Patir-Cheng flow model is used to investigate the influence of the rough surfaces, and a modified one-dimensional Reynolds equation is used to determine hydrodynamic pressure. Greenwood-Tripp model is also used to calculate asperity-asperity contact in the mixed lubrication regime. The textures of diameters 100 μm and 120 μm on the parabolic piston ring are optimized. For the optimization, only power stroke and suction stroke are considered out of four-stroke. The results showed 27% and 21% friction reduction with 100 μm and 120 μm, respectively, for suction and power strokes, compared to an untextured ring. This investigation would be useful for determining design parameters for improving the ring-liner pack in the IC engine.