Equivalent boundary model for turbine film cooling prediction

Film cooling is a crucial technology for the thermal protection of gas turbines. The simulation of film cooling with mesh-resolved structures remains a time-intensive process, posing significant challenges for turbine optimization. To reduce the computational cost, this paper introduces an innovative equivalent boundary model (EBM) for predicting turbine film cooling. The proposed approach numerically characterizes the coolant jet process by modeling jet injection through the flow function and correcting jet mixing interactions using heat enthalpy balance principles. Validation was performed on a flat plate, the experimental results and the mesh-resolved simulations were used as a comparison. Different indicators of film cooling including mesh sensitivity, cooling efficiency, and flow distribution are examined. Notably, a comprehensive implementation framework for turbine prediction is proposed for the first time, with further applications extending to a turbine vane cascade and a turbine stage. The results show that the cooling effectiveness and aerodynamic performance predicted by EBM closely align with the mesh-resolved simulations and experimental results. Furthermore, for several test cases, the required computational grid was reduced by 20%, 23%, and 38%, respectively, leading to an average simulation time savings of approximately 30%. Providing an effective and efficient tool for predicting and optimizing air-cooled turbines.