Development of a Predictive Model for Preliminary Gas Turbine Blade Cooling Design and Analysis

Abstract

Improvements in turbine blade cooling are crucial in order to increase the thermal efficiency of modern gas turbines. Designing highly efficient cooling concepts and evaluating their impact on the thermodynamic cycle performance during early design phases is therefore becoming increasingly important. The cooling air requirements are commonly approximated using simplified empirical correlations which cannot represent future-oriented cooling designs with sufficient accuracy. In the current work, a simplified yet physics-based predictive model for turbine blade cooling design and analysis has been developed. The model is capable of calculating the material temperature distribution along the blade surface as well as the coolant mass flow rate. Commonly used cooling correlations are implemented which can further be supplemented by novel cooling techniques due to the modular structure. The model is used to create a cooling design for the first stage high pressure turbine nozzle guide vane of the DLR's ultrahigh bypass ratio engine concept. A detailed analysis of the cooling concept is presented to demonstrate the capabilities of the developed tool.