A MULTI-PHYSICS STUDY OF THE EFFECT OF FLUID-THERMO-STRUCTURE INTERACTIONS ON THIN FILM COATINGS UNDER EXTREME ENVIRONMENTS
Numerical simulations of the thermal-mechanical responses in thermal barrier coatings (TBCs) with a round film cooling hole under gas turbine operating conditions are conducted using the commercial software ANSYS. The thermal stresses on a representative TBC turbine blade caused by the interaction of the main stream hot gas flows and the coolant flows from the cooling holes are analyzed. The complicated temperature distribution between the two gas flows results in large temperature gradients and significant stress concentrations near the cooling holes, with a peak at the trailing edge. The large stresses are expected to accelerate TBC spallation and failure under thermal cycling. The temperature distribution and resulting stresses for a circular and elliptic cooling hole are compared. The increased width and decreased length of the elliptical hole results in a greater cooling effectiveness yet larger stresses when compared to the circular hole.