Multi-objective Optimization and Sensitivity Analysis of the Parameters Affecting Sealing Performance of the Piston Rings Face through the Validated Model for the Four-stroke Bi-fuel Engine

Abstract

A multi-objective optimization study and sensitivity analysis of a SI engine piston-rings pack using dynamics analysis software (AVLExcite Piston&Rings) and optimizer software (modeFRONTIER) are presented. The effects of changing the piston rings' tangential force and face profile on the oil and gas flow behavior inside the piston-rings pack are investigated by calculating the lubrication oil consumption, blow-by, and power losses. The feasibility of the simulation model was determined by comparing it to empirical data obtained from experimental testing of the engine to estimate the amount of oil consumption and blow-by gas flow. Using the statistical modeling algorithm SS-ANOVA, multi-objective optimization investigates the individual and interaction effects of the three rings' tangential forces. This method significantly reduces the time and cost required to find the optimal design, an approach not reported in previous studies. The results showed a strong correlation between simulation and experimental test results, indicating an acceptable match during model validation. Furthermore, the predictions show that tangential forces affect sealing performance; thus, modifying the tangential force resulted in a 30% reduction in oil consumption and less than a 0.8 percent increase in friction. Furthermore, the LKZ oil control ring model efficiently reduces oil consumption by 25% while slightly increasing friction (about 10 percent without face coating).