Finite Element Analysis of Thermal-Mechanical Behavior in the Thermal Barrier Coatings With Cooling Hole Structure

The present work aims to investigate the thermal-mechanical behavior in thermal barrier coatings (TBCs) with a round film cooling hole under gas turbine operating conditions. The adiabatic wall temperatures and surface heat transfer coefficients are firstly calculated for thermal boundary conditions. Subsequently, stress analyses during both thermal exposure and cooling down period are presented. The results show that: although the cooling hole has lower temperature, large stress concentration still appears because of the geometry of cooling holes and thermal mismatch between TBCs and substrate. The huge thermal stress may lead to pre-mature failure of TBCs, which should be carefully considered in the design of film cooling-TBC system.