Optimal Design of Novel Laminated Cooling System Considering Cooling Effectiveness and Thermomechanical Performance

Abstract

Abstract Laminated cooling is deemed as one of the most potential and novel cooling technologies for turbine blade to increase turbine inlet temperature, which combines the superiority of film cooling, pin fin cooling and impingement cooling. To realize optimal design, the multidisciplinary design optimization of laminated cooling configuration is conducted considering cooling performance under acceptable pressure loss and thermomechanical performance. A coupled multidisciplinary analysis model is established to perform aerodynamical analysis, heat transfer analysis and thermomechanical analysis. Based on parametrized laminated model and Design of Experiments method, the cooling effectiveness, pressure loss coefficient and maximum stress can be obtained under different design parameters and their dominated design variables can be clarified. Using these sampling points, a Kriging approximation surrogate model can be established to replace real numerical calculation process and balance the efficiency and fidelity. Finally, the multi-island genetic algorithm is used to find the maximum cooling effectiveness and minimum pressure loss under the constraint of maximum stress. Results shows that, the dilation of film hole diameter, pin fin diameter and impingement hole diameter and the reduction of target plate thickness can effectively improve cooling performance and meanwhile decrease maximum stress, which can be up to 17.68% and 4.96% separately under the acceptable poressure loss coefficient raise of 16.8%. That can be attributed to the enhancement of inner heat transfer and improvement of outer film cooling.