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
modelto simulate themicrostructural 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 circumferentialspacing: 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 filmthicknessincreased by 0.56%and 7.49%, and
the minimum oil film thicknessincreased by 29.80% and 34.51%