A parametric model for probabilistic analysis of turbine blades considering real geometric effects

Kay Heinze, Jens Scharfenstein, Matthias Voigt, Konrad Vogeler, Marcus Meyer

This paper addresses the consideration of manufacturing and deterioration effects of gas turbine blades in a probabilistic setting. Currently, during design these effects are covered by safety factors and conservative assumptions. The probabilistic investigation, on the other hand, will enable us to calculate the effect of variability on stresses and relevant aerodynamic quantities such as efficiency, thus providing the foundation for robust blade design. A set of 500 new and used turbine blades, provided by Rolls-Royce Deutschland, was digitised with an optical scan system. Cooling holes and abrasion effects were statistically analysed and removed from the scanned data set. Classical turbine parameters were identified. Finally the variability (probability density functions and corresponding parameters) of the geometric parameters can be calculated according to the digitised geometries and the manufacturing process can be statistically analysed. The presented parametric model will provide the basis for upcoming numerical probabilistic assessment of the real geometric effects.

Kay Heinze, Jens Scharfenstein, Matthias Voigt, Konrad Vogeler, Marcus Meyer
"A parametric model for probabilistic analysis of turbine blades considering real geometric effects"
To be published in CEAS Aeronautical Journal 2013