Turbine Blade Thermal Design Process Enhancements for Increased Firing Temperatures and Reduced Coolant Flow

Abstract

A successful implementation of a cooled turbine blade design for a heavy duty gas turbine engine is a technology challenge that requires a stringent engineering approach. The increased spread of hot gas versus metal temperature, the flatter temperature profiles for reduced emissions and the aerodynamic 3D-profile shape requirement and all at a reduced cooling air consumption place the specification of a new turbine blade, that is put forward to the aerothermal engineers, as a technical challenge. It is also desired to reduce the available development time to be able to introduce new technology features faster into the market. The paper aims to demonstrate turbine blade cooling and heat transfer design process enhancements that allow: increased thermal predictability, increased capturing of three dimensional effects and reduced engineering development cycle time from initial design to full engine validation. Selected items will be shown for demonstration. One example is the use of symmetry and parameterization to move CFD from an analysis tool into an available design tool to capture effects as rotation or three-dimensionality. Another example is the use of heat sinks within a finite element model to represent individual cooling holes instead of hole geometry.