ADVANCES IN NONLINEAR STRESS ANALYSIS OF A STEAM COOLED GAS TURBINE BLADE

In this paper to study the thermoelastic behavior of a gas turbine blade, a computer code based on Conjugate Heat Transfer method was developed to solve the coupled external flow field and the internal temperature field inside a gas turbine blade. An interpolation method based on the 3D shape functions was used to calculate the correct temperature values at the boundaries to determine the stress field. For the materials with temperature dependent mechanical and physical properties, the thermal stresses exhibit a nonlinear behavior. In these cases, an analytic solution for the energy and equilibrium equations to obtain the temperature distribution and the stress field, knowing K(T), alpha(T), E(T) would be impossible and the numerical schemes should be employed instead. The results show that the stress for the materials with temperature dependent properties is higher than that for the cases where the blade material properties are constant with temperature. Further, the temperature field and the flow field obtained by the present method were compared to the available experimental findings. The results show a good agreement.