排气歧管流固耦合仿真与试验

针对发动机排气歧管的断裂问题,对某发动机排气歧管的热负荷进行流固耦合分析,并在台架试验中测量其温度场和应变.考虑热辐射和材料的非线性,建立排气歧管的内流场CFD模型、传热模型和有限元模型,分析得到排气歧管的温度场、应力场和塑性应变云图等.仿真结果与试验结果吻合较好.仿真结果表明排气歧管汇合处的温度最高,塑性应变最大位置与试验测得的断裂危险区域吻合.

Fluid structure coupling simulation and experiment for engine exhaust manifold

As to the fracture of engine exhaust manifold,the thermal load on an engine exhaust manifold is analyzed by fluid-structure coupling analysis,and the temperature filed and strain is measured by bench test.Considering thermal radiation and material nonlinearity,the internal flow field CFD model,heat transfer model and finite element model are built,and the temperature field,stress field,plastic strain contour and so on are obtained by the analysis.The simulation results are in good agreement with the test results.The simulation results indicate that the maximum temperature locates on the confluence of exhaust manifold,and the location of maximum plastic strain matches the fracture zone measured by the test.