Tools for Estimating Resonant Stresses in Turbine Blades

The problem of obtaining adequate aerodynamical boundary conditions for an analyzed blade is important to predict resonant stresses. According to this, three different CFD approaches of stator-rotor modeling have been investigated for obtaining gas dynamic loading: 1. 3D averaged and then quasi-3D unsteady calculations. 2. Fully 3D unsteady calculations using commercial CFX solver. 3. Fully 3D unsteady calculations using the in-house solver. To carry out 3D structural analysis the ANSYS software and our subroutines have been applied. The methodology to estimate damper ratio for the different mode shapes and mode numbers has been developed. As a result, the tools to predict the resonant stress have been created where we tried to take into account all main factors affecting resonant stress level. The HPT first stage blade of a modern aircraft engine was chosen as an example of using our tools for prediction of resonant stresses level. A comparison of experimental data and obtained calculation results showed good agreement.