气缸盖周期性瞬态温度场仿真分析

摘要

为研究气缸内高温燃气周期性加热作用下气缸盖温度场及其变化规律，建立了某柴油机气缸盖有限元分析模型，利用流固耦合方法计算了气缸盖稳态温度场，在火力面施加瞬时热边界进行了热分析，得到了4个工作循环的气缸盖瞬态温度场。结果表明：额定工况运行时气缸盖火力面温度剧烈波动，幅值达到了22℃，峰值温度高达279．9℃，温度波动在火力面深度2．79 mm的薄层内较为明显，但随深度的增加会逐渐减小。%To study the temperature field and its change laws of cylinder head under periodic high temper -ature gas, a finite element model of diesel engine cylinder is built .Steady temperature filed is calculated through fluid solid coupling method .Transient thermal boundary conditions are imposed to fire face for thermal analysis , and 4 cycles of transient temperature filed of cylinder head are obtained .Results show that periodic heating effect by high temperature gas will cause significant impact to cylinder head fire face.The temperature amplitude reaches to 22℃and the highest temperature reaches to 279.9℃at ra-ted working condition .The temperature fluctuation caused is obvious at a thin layer within 2 .79 mm of fire face, and decreases with the increase of depth .