Fully coupled forced response analysis of nonlinear turbine blade vibrations in the frequency domain

• DOI: 10.1016/j.jfluidstructs.2024.104112
• Publication Date: 2024-04-15T16:15:32Z
• Authors: Christian Berthold; Johann Gross; Christian Frey; Malte Krack
• Keywords: Turbomachinery; Shroud; Harmonic balance; Solver; Rotordynamics

For the first time, a fully-coupled Harmonic Balance method is developed for forced response of turbomachinery blades. The applied to state-of-the-art model turbine bladed disk with interlocked shrouds subjected wake-induced loading. recurrent partial opening and closing pre-loaded shroud contact causes softening effect, leading turning points in amplitude–frequency curve near resonance. Therefore, coupled solver embedded into numerical path continuation framework. Two variants are developed: solution path, re-iteration selected points. While variant slightly more costly per point, it has important advantage that can be run completely parallel, which substantially reduces wall clock time. It shown wake- vibration-induced flow fields do not linearly superimpose, severe under-/overestimation resonant vibration level by influence-coefficient-based methods (which rely on this linearity assumption).