A fast finite element model based tool has been developed to calculate the natural frequencies of fundamental modes of cooled gas turbine bladed disk assemblies during conceptual design. The tool uses shell elements to model the airfoil, shank, and disk, and achieves order of magnitude reduction in computation time allowing exploration of a wide design space at the preliminary design stages. The analysis includes prestress effects due to centrifugal loading and approximate temperature loading on the parts. Sensitivity studies are performed to understand the relative impact of design features such as airfoil internal geometry, bond coat, and thermal barrier coating on the system natural frequencies. Critical features are selected which need to be modeled to get an accurate natural frequency estimate. The results obtained are shown to be within 5% of the frequencies obtained from a full-fidelity finite element model. A case study performed on seven blade designs illustrates the use of this tool for quick aeromechanical assessment of a large number of designs.

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