Research on Analysis of Friction and Lubrication Characteristics of Piston-Cylinder System in Internal Combustion Engines Using Improved Multi-Layer Thermal Resistance Model

Abstract

To analyze the friction and lubrication characteristics of the piston-cylinder system in internal combustion engines using an improved multi-layer thermal resistance model, this study combines the theory of thermal boundary conditions to design a lubrication and friction calculation model, and conducts numerical computations and experimental research. Firstly, a lubrication model for the piston skirt-cylinder liner is proposed, which includes key parameters such as the lubrication model for the piston skirt and the lubricating oil characteristic equation. Secondly, the friction and lubrication theory for the piston ring-cylinder liner is discussed, which includes the leakage model and the piston ring lubrication model. Additionally, the multi-layer thermal resistance model is improved to accurately describe the lubrication of the piston assembly under the thermal boundary conditions of the cylinder liner. Subsequently, experimental research is conducted to investigate the friction and lubrication characteristics of the piston-cylinder system in internal combustion engines under different temperatures. The experiments reveal that: (1) Linear function 1 and sinusoidal function 1 perform well in the piston skirt of the cylinder liner, with lower average friction power consumption and relatively small relative errors of 5% and 6%, respectively. (2) In the experimental study of the friction and lubrication characteristics of the piston ring-cylinder liner, function 2 in the linear function approach has slightly higher average friction power consumption compared to function 1. In the parabolic function approach, function 1 exhibits lower average friction power consumption, while function 2 significantly increases it. In conclusion, this research comprehensively explores the friction and lubrication characteristics of the piston-cylinder system in internal combustion engines by introducing an improved multi-layer thermal resistance model. The aim of this study is to provide theoretical foundations and experimental evidence for further optimizing the design and operation of internal combustion engines.