Application of the Kriging model combined with the whale algorithm in the optimization analysis of the micro-texture effect on the performance of the engine piston ring/cylinder friction pair

Abstract

In order to study the influence of microstructure and improve the efficiency of the engine friction pair, the engine piston ring/cylinder liner friction pair is selected as the research object. This paper analyzes and evaluates the influence of microstructural geometric parameters on the performance of friction pair. The Kriging model is used as a parametric model to simulate the microstructural parameters and combined with the whale optimization algorithm to optimize the microstructural parameters. The optimal microstructural parameters of the piston ring/cylinder liner friction pair are obtained as follows: ellipse long half:15.3 μm, short half axis: 14.9 μm, offset: 6.5 μm, depth: 7.7 μm; axial spacing: 45.5 μm, and circumferential spacing: 261.2 μm. Compared with the prototype piston ring/liner friction pair, the average friction coefficients of piston ring/cylinder liner friction pair with unoptimized microstructure and optimized microstructure were, respectively, reduced by 10.88% and 13.99%, the average bearing pressure was increased by 23.75% and 24.12%, the average friction power decreased by 9.24% and 12.89%, the average oil film thickness increased by 0.56% and 7.49%, and the minimum oil film thickness increased by 29.80% and 34.51%.