AERO-THERMAL COUPLED PREDICTIVE MODEL FOR PRELIMINARY GAS TURBINE BLADE COOLING ANALYSIS

摘要

The turbine inlet temperature has been increasing over the years to improve gas turbine efficiency and specific power. Blade cooling technology is essential to keep component temperatures below their critical value, and this makes the aero-thermal coupled phenomenon more significant. Blade life assessment is closely related to blade metal temperature distribution and gradients, and blade cooling analysis is always considered starting from the preliminary design stage. However, traditional blade cooling analysis for preliminary design is always based on external boundary conditions determined by experience, which affects the prediction accuracy as the interaction effect between the main flow and coolant is not considered. In this paper, an aero-thermal coupled blade cooling model is further developed by combining the improved streamline curvature method with a one-dimensional thermo-fluid network. This model is capable of predicting blade surface temperature distribution and internal coolant flow conditions in the preliminary phase of blade cooling design with a limited amount of input information. Experimental data for the NASA C3X profile with film cooling was selected for validation. In addition, a sensitivity analysis was performed on different film cooling mass flow rates to demonstrate the model flexibility for different boundary conditions.