基于直接流固耦合的发动机排气歧管热应力分析

摘要

应用计算流体力学软件STAR-CCM+计算了发动机排气歧管的瞬态内流场,得到排气歧管内壁面的热边界条件,根据经验值给定排气歧管外壁面的热边界条件,进一步计算排气歧管的温度场及热应力.计算结果表明,发动机排气歧管在支管交汇处温度最高,达到969K,其熟应力在140MPa以下.%CFD software STAR-CCM + was used to calculate the instant internal flow field of manifold to get its thermal boundary condition, and the thermal boundary condition of external wall of exhaust manifold was given by empirical value, then STAR-CCM + software was used to calculate the temperature field and the thermal stress field of exhaust manifold . The calculated results showed the highest temperature area which reached 969 K was at the junction of branch pipes, and thermal stress of exhaust manifold was below 140 MPa.