燃烧室部件耦合系统过渡工况传热全仿真模拟研究

Heat Transfer Simulation of Combustion Chamber Components Coupled System Under Transient Condition

内燃机在起动、停车、加载等运行工况发生急剧变化 (过渡工况 )过程中 ,其燃烧室部件处于强烈地被加热或被冷却状态。这种热冲击增加了部件的动态疲劳热应力 ,给内燃机的可靠性带来严重恶果 ,是导致燃烧室部件破裂的主要原因之一。燃烧室部件的传热研究是热负荷计算和评定的基础 ,对内燃机的可靠性设计具有重要意义。作者对燃烧室部件活塞组 -气缸套耦合系统在过渡工况下的耦合传热关系进行了较深入的研究 ,建立了描述这一传热过程的数学模型 ;并利用该模型 ,模拟了 12 5风冷柴油机在各种过渡工况下的传热情况。

While an internal combustion engine is under changing(transient) working condition,for example:starting,stopping and loading working condition et al.,its combustion chamber components are heated and cooled violently.Since this kind of thermal shock increases the dynamic fatigue thermal stress of comoponent,it reduces the reliability of internal combustion engine significantly,and is the main destruction reason of combustion chamber components.As the basis of thermal load calculation and evaluation heat transfer research has an important significance for the reliability design of internal combustion engine.In this paper,the coupled heat transfer relationship on piston set-liner under transient working condition is studied thoroughly,and the heat transfer models simulating this heat transfer process is set up.Using these models,the heat transfer process of a 125 type air-cooled diesel engine under various transient working condition are imitated.