基于一维模拟的排气歧管流固耦合瞬态热管理  

Fluid-Solid Coupling Transient Thermal Management of Exhaust Manifold Based on One-Dimensional Simulation

作　　者：赖晨光[1,2] 胡瑞 周毓婷 LAI Chenguang;HU Rui;ZHOU Yuting(Key Laboratory of Advanced Manufacture Technology for Automobile Parts,Ministry of Education,Chongqing University of Technology,Chongqing 400054.China;Institute of Fluid Science,Thohku University,Japan)

机构地区：[1]重庆理工大学汽车零部件先进制造技术教育部重点实验室,重庆400054 [2]东北大学流体科学研究所,日本

出　　处：《重庆理工大学学报（自然科学）》2020年第1期118-125,共8页Journal of Chongqing University of Technology：Natural Science

基　　金：国家自然科学基金资助项目(51305477);日本东北大学共同研究(国际合作)项目(J181092)

摘　　要：由于高温高压气体的流动冲击,发动机排气歧管会产生较大的温度梯度并承受较大的热应力。以热应力和应变为目标,该研究对某车型发动机排气歧管进行优化。首先对一维发动机进行建模和计算,利用流固耦合方法计算排气歧管的温度场,并做了网格无关性的验证。将结果作为热负荷,计算排气歧管的热疲劳参数并以热应力和热变形为目标对该排气歧管进行改进。结果表明:改进后的排气歧管热应力和热变形明显降低,其中最大热应力减小了21MPa,降幅为8.5%;热应变减小了0.07 mm,占4%,疲劳寿命提高了约1100次。该研究为车辆发动机排气歧管的设计和优化提供了一种有效的方法,具有参考意义。Due to the flow of high temperature and high pressure gases,the engine exhaust manifold is always subjected to large temperature gradients and thermal stresses.With the aim of thermal stress and strain,this study aims to optimize the engine exhaust manifold of a certain model.Firstly,the one-dimensional engine is modeled and calculated.The fluid-solid coupling method is used to calculate the temperature field of the exhaust manifold,and the grid-independent verification is performed.Using the results as a thermal load,the thermal fatigue parameters of the exhaust manifold are calculated and the exhaust manifold is modified with the aim of thermal stress and thermal deformation.The results show that the improved exhaust manifold thermal stress and thermal deformation are significantly reduced,the maximum thermal stress is reduced by 21 MPa,the decrease is by 8.5%;the thermal strain is reduced by 0.07 mm,accounting for 4%,and the fatigue life is increased by about 1100 times.This study provides an effective method for the design and optimization of vehicle engine exhaust manifold,which has important reference significance.

关 键 词：流固耦合 一维模拟 瞬态 CFD 

分 类 号：U463[机械工程—车辆工程]