Exploration of Simulation Strategies for Modelling Conjugate Heat Transfer Across Thermal Barrier Coatings on Gas Turbine Blades

Thermal Barrier Coatings (TBCs) are essential ceramic layers that insulate the underlying blade components from extremely hot combustion gases in gas turbines. This protection prevents thermal degradation, extends component lifespan, and critically, allows the engine to operate at higher temperatures for improved efficiency and power output. Accurate simulation of TBCs on gas turbine blades is crucial for performance prediction and design optimization. While conventional Conjugate Heat Transfer (CHT) simulations for gas turbines have widely employed simplified contact resistance models for TBCs, these can lead to inaccuracies in heat transfer and differences in temperature predictions on the underlying substrate metal. Higher fidelity TBC models are a large contributor to more accurately predicting blade temperatures for optimizing blade design. In this paper, various simulation strategies for modelling conjugate heat transfer across TBCs on gas turbine blades are explored. The Siemens Energy Gas Turbine Demo Blade 5000F is simulated in Simcenter STAR-CCM+ using three distinct TBC modelling strategies: (1) Contact Resistance Modelling, (2) Solid Shell Modelling, and (3) 3D Solid Modelling. The principles underlying each strategy are first outlined. The three TBC modelling strategies are then compared and contrasted on their resulting solution accuracy and computational performance. Finally, it is concluded that while 3D Solid Modelling offers the highest fidelity for detailed design evaluation, Solid Shell Modelling provides an optimal balance of accuracy and computational efficiency, significantly accelerating run times in Simcenter STAR-CCM+. These findings provide valuable guidance for TBC simulation methodology selection, streamlining design optimization and accelerating the development of more durable and efficient gas turbine engines.