Numerical and multi-objective optimization of thermal barrier coatings for gas turbine blades using coupled FDM–FEA framework

Abstract Gas turbine blades operate under severe thermo-mechanical conditions, requiring advanced thermal barrier coatings (TBCs) to improve thermal resistance, structural durability, and operational reliability. The present study developed a coupled finite difference method (FDM) and finite element analysis (FEA) framework to evaluate and optimize the thermo-mechanical behaviour of coated gas turbine blades under operating temperatures exceeding 1,200 °C. A two-dimensional transient thermal model was implemented in MATLAB to predict temperature distribution across YSZ, Al 2 O 3 , SiC, and TiN-coated blades. The computed thermal field was subsequently incorporated into a three-dimensional finite element model to investigate stress, strain, and displacement behaviour under combined thermal and rotational loading. Comparative analysis demonstrated that YSZ coatings provided superior thermal insulation, reducing substrate temperature by approximately 15–20 % due to their lower thermal conductivity. Parametric investigation revealed that increasing coating thickness improved thermal resistance but intensified interfacial stress due to thermal mismatch. Multi-objective optimization identified an optimum coating thickness of approximately 400 µm, achieving balanced reduction in temperature and stress. Functionally graded coatings further reduced interface stress by nearly 16–18 % compared with conventional uniform coatings. The developed framework demonstrated reliable numerical convergence, with prediction errors below 5 %, confirming its suitability for advanced turbine coating design applications.