Thermal and Thermo-Mechanical Fatigue Simulations of Thermal Barrier Coating on an Automotive Catalytic Converter

Due to its insulation effectiveness at low packaging space, Thermal Barrier Coating (TBC) is identified as an effective heat shielding solution. Such usage of TBC on an automotive exhaust catalytic converter requires virtual validation through numerical simulations before physical systems are built and tested. The objective of this study is to analyze the effect of TBC on Thermal Insulation and Thermo-Mechanical Fatigue (TMF) performances of a catalytic converter using simulations. The sample component is coated with TBC material 8% Yttrium-Stabilized-Zirconia (8YSZ) for 250 µm thickness. The insulation effect of this coating is computed by thermal simulation using Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD) Analysis. An input Computer Aided Design (CAD) model from Catia V5 is converted into a FEA model by using the commercial tool. Hypermesh and numerical simulations are done by using commercial tools such as, Star CCM+ (Ver 2022.1) and TAITherm. The outer surface temperature of the catalytic converter is computed with and without TBC. As a result, reduction of ~70 °C – 100 °C is observed on the outer surface of the component when coated with 8YSZ coating. In addition, the mechanical durability of the TBC on the exhaust system is predicted by thermo-mechanical fatigue analysis, by using the commercial tool Abaqus. It is concluded that the TBC coating improves the TMF life of the component by 69% for the given inlet cone geometry. Hence, the established numeric analyses can assess the effect of applying TBC coating on the exhaust catalytic converter for both thermal insulation and TMF durability performances.