某柴油发动机排气歧管的热强度分析

Analysis on Thermal Strength of Exhaust Manifold of a Diesel Engine

文章基于流固耦合方法,应用Star ccm+软件对某柴油发动机的排气歧管内流场及外流场进行模拟分析,得到流体域及固体域的温度分布及表面热传递系数;采用Ramberg-Osgood方法拟合了高温时材料的塑性应力应变曲线;将温度场导入Abaqus软件中作为温度载荷计算温度影响下的歧管热应力和热应变;最终,找出存在应力集中和塑性变形的区域.结果表明:排气歧管温度场的分析值与试验值基本吻合,且通过了相关试验的验证.

The fluid-solid coupling method is adopted to analyze the fluid and solid temperature field of a certain diesel engine exhaust manifold using Star ccm+software.The Ramberg-Osgood method is used to fit the curve of plastic stress-strain at high temperatures.The temperature field is imported to Abaqus software as the boundary condition.The thermal stress and strain results of the exhaust manifold are obtained.Finally,the areas with stress concentration and plastic deformation are identified.It shows that the CAE temperatures of the manifold are matched with test data,and the manifold is validated by the relevant tests.