AERO-THERMO-STRUCTURAL ANALYSIS AND DESIGN OPTIMIZATION OF GAS TURBINE BLADES USING FINITE ELEMENT TECHNIQUE

Abstract

This work presents the numerical modeling of gas turbine blade su bjected to high temperature flow stream. Continuity, momentum, and energy equations along with high Reynold s number k-E turbulence model were solved using a finite-element computer program. Temperature and velocity fields were presented at different Reynolds numbers for extensively tested airfoil.

Results from flow computations were used as a boundary conditions for coupled field thermal-structure analysis. The thermal stress due to the computed temperature distribution was obtained throughout the turbine blade airfoil with and without convection cooling configuration. The turbine blade service life under combined thermal fatigue-creep failure mode was predicted using strain ranges partitioning methods.

Starting by initial turbine bl ade configuration with internal convective cooling, the optimum geometrical configuration of the turbine blade is determined. The geometrical parameters such as the number of holes, their diameters and arrangements are determined to give the best configuration. This optimized configuration maximizes the blade service life at the highest possible stream temperature where as minimizing the required mass flow rate for the cooling holes, thus decreasing the aerodynamic losses associated with it.