Research on the optimization design method of ribbed cooling galleries in lightweight steel pistons based on heat transfer performance

The use of steel pistons in high-performance diesel engines is limited by their low thermal conductivity and high density. To improve heat transfer performance and reduce the mass of steel pistons, a rectangular cross-section rib structure was introduced into the cooling gallery. Further, a parametric model of the ribbed cooling gallery controlled by 7 design variables was established, and an optimized design method for the gallery structure was proposed in combination with intelligent algorithms. The results show that compared with the original steel piston with a mass of 978.27 g and the highest temperature of 446.15 degrees C, the optimized feature designs can achieve maximum reductions of 15.59 % and 5.94 % respectively. In addition, the highest temperatures and maximum thermal deformations in critical regions of the feature designs are all lower than those of the original design. The maximum thermal stresses are also lower than in the original steel piston except in the region of the rim and the first ring groove. However, the maximum values are still within the safe design range of the steel pistons. This paper can provide new insights into the optimization of steel pistons for mass reduction and enhanced heat transfer performance.