Piston cooling gallery plays a critical role in managing the temperature of the piston and its performance. This paper aims to study the effect of oscillatory heat transfer within the cooling galleries, focusing on two distinct types: flanged (friction-welded) and smooth structures (laser-welded). To do so, the Eulerian multiphase flow model and the k-ω SST turbulence model were used to simulate the oil and air flow through the cooling gallery. Key parameters such as the oil filling rate, wall heat transfer coefficient, oil outlet flow rate, heat removal rate by the oil, and overall wall heat transfer rate were assessed for both gallery designs at an engine speed of 1800 r/min. The results indicate significant disparities between the two cooling gallery structures: the smooth structure exhibits an oil filling rate that is 5.41% higher and an oil outlet flow rate that is 33.48% greater compared to the flanged structure. The flange structure impedes internal oil movement, which leads to boundary layer separation, secondary wall contact, and the emergence of a double vortex phenomena. Collectively, these factors influence the oil fill ratio. This, in turn, affects the distribution of oil within the gallery and, subsequently, the efficiency of heat transfer. Comparative analyses of heat transfer within both galleries, under the same studied conditions, revealed that the smooth structure outperforms the flanged one. However, the presence of a flange significantly alters the heat contribution from different walls, thereby highlighting the substantial impact of flanges on the overall efficiency of heat transfer.

中文翻译：

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钢活塞冷却通道中油振荡对热传递的影响比较：摩擦焊接与激光焊接


活塞冷却通道在管理活塞温度及其性能方面起着至关重要的作用。本文旨在研究冷却通道内振荡传热的效果，重点关注两种不同的类型：法兰（摩擦焊接）和光滑结构（激光焊接）。为此，使用欧拉多相流模型和 k-ω SST 湍流模型来模拟通过冷却通道的油和空气流。在发动机转速为 1800 转/分钟的情况下，对两种油道设计的关键参数（例如油填充率、壁传热系数、油出口流量、油的散热率和整体壁传热率）进行了评估。结果表明，两种冷却通道结构之间存在显着差异：与法兰结构相比，光滑结构的充油率高出 5.41%，出油流量高出 33.48%。法兰结构阻碍了内部油的运动，导致边界层分离、二次壁接触、出现双涡现象。总的来说，这些因素影响着油填充率。这反过来又影响油在通道内的分布，进而影响传热效率。在相同的研究条件下，对两个通道内的传热进行比较分析表明，光滑结构优于法兰结构。然而，法兰的存在显着改变了不同壁的热量贡献，从而凸显了法兰对传热整体效率的重大影响。