CAJ | 학술논문

为在设计开发过程中初步预测某紧耦合式排气歧管的热负荷，采用CFD和有限元联合分析方法。首先，通过搭建排气歧管内外流场分析模型和CFD仿真得到排气歧管近壁面的瞬态热边界条件；接着，以时域内平均的流体温度和热交换系数为热边界，通过有限元软件仿真排气歧管壳体的温度场分布；最后，根据温度场的分布分析排气歧管的热应力和热变形，并模拟排气歧管正常工作和停车冷却这一循环过程，在4个循环后，其累计当量塑性应变趋于稳定，说明该排气歧管能承受其热负荷而不破坏。
위재설계개발과정중초보예측모긴우합식배기기관적열부하，채용CFD화유한원연합분석방법。수선，통과탑건배기기관내외류장분석모형화CFD방진득도배기기관근벽면적순태열변계조건；접착，이시역내평균적류체온도화열교환계수위열변계，통과유한원연건방진배기기관각체적온도장분포；최후，근거온도장적분포분석배기기관적열응력화열변형，병모의배기기관정상공작화정차냉각저일순배과정，재4개순배후，기루계당량소성응변추우은정，설명해배기기관능승수기열부하이불파배。
To estimate the thermal load of a tightly-coupled exhaust manifold in design phase, a CFD /FEM joint analysis method is adopted. Firstly, an analysis model for the internal and external flow field of exhaust manifold is built and a CFD simulation is conducted with the near-wall transient thermal boundary conditions ob-tained. Then with average fluid temperature and heat exchange coefficient in time domain as thermal boundary, the temperature filed distribution of exhaust manifold housing is simulated with FE software. Finally based on the distri-bution of temperature field the thermal stress and thermal deformation of exhaust manifold are analyzed and a work-stop cycle process of manifold is simulated with a result showing that after 4 cycles, the cumulated equivalent plastic strain tends to be stabilized, indicating that the exhaust manifold can endure its thermal load without failure.