某发动机排气歧管热应力仿真与分析

Thermal-Stress Simulation and Analysis of Exhaust Manifold

运用GT-POWER、STAR-CCM+与ABAQUS软件,采用流固耦合的分析方法,对某发动机排气歧管进行温度场与热应力场分析,并针对分析结果进行若干优化改进。首先利用GT-POWER仿真得到流体计算中所需的入口条件,再利用STAR-CCM+软件对排气歧管进行流体分析,并将得到的排气歧管壁面温度以及对流换热系数映射到ABAQUS的固体网格上得到温度场,通过ABAQUS进行热应力以及热变形分析,得出排气歧管开裂是热应力过高所致。据此对排气歧管进行若干结构改进,经对比确定方案3可有效减小排气歧管热应力,说明该方案是解决排气歧管开裂问题的有效方法。

Using fluid-solid coupling method, the temperature and thermal stress field of a certain engine exhaust manifold is analyzed by GT-POWER, STAR-CCM＋ and ABAQUS, and some optimization and improvement are made for the analysis results. Firstly, the inlet conditions of the fluid are obtained by GT-POWER simulation~ Then fluid analysis is carried out in the exhaust manifold by star-ccm＋. Finally, the exhaust manifold wall temperature and heat transfer coefficient are mapped to the ABAQUS solid mesh, and temperature field is obtained. The thermal stress and thermal deformation of the exhaust manifold are analyzed by ABAQUS, and the cracking of ihe exhaust manifold is caused by the thermal stress. Based on this, the exhaust manifold is improved, and scheme 3 can effectively reduce the thermal stress of exhanst manifold. This scheme is an effective method to solve the problem of the cracking of the exhaust manifold.