The Thermal Mechanical Fatigue (TMF) Analysis for an Exhaust Manifold – A Simple Application of File Based Coupling

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With stringent emission and fuel economy regulations, downsizing and improved performance has been an recent trend in IC engine design. Higher performance introduces high exhaust temperatures in the exhaust system, which was designed to withstand high temperatures, large vibrations and stress from leakage-proof seals of tightened bolts.

In this paper, thermal analysis coupled with mechanical  analysis was applied to the exhaust system of a 2.2L turbocharged engine in the early design stage. The engine operation cycles used were focused on rated power, motoring and idle conditions and were simulated by a 1D simulation tool (AVL Boost software), from which the output was used as the boundary conditions for STAR-CCM+® to calculate the temperature fields and heat transfer coefficients. The structures model built in Abaqus was also imported in STAR-CCM+ to map the data for the fluid-structure interface. The local Heat Transfer Coefficient (HTC) and reference temperature (cycle time averaged) were mapped to surfaces of the structures model  and exporedt as an individual Abaqus input files for each surface. All mapped data for each condition were included in the Abaqus heat transfer transient calculation at specific steps. The predicted initiated cracks were compared with thermal shock tests, which showed a close match with the test results.

Author Company: 
HAITEC
Author Name: 
Shao-Chin Fan