Uncertainty quantification and sensitivity analysis on the aerodynamic performance of a micro transonic compressor

Micro gas turbines are inevitably subject to geometric and operational uncertainties, which are increasingly detrimental to aerodynamic performance and reliability. However, the effect and mechanism of coupled uncertainties on performance are still unclear. In this paper, a framework for uncertainty quantification and global sensitivity analysis of a micro transonic compressor is established. To make the process tractable, the sparse grid-based polynomial chaos expansion method is used to propagate the coupled uncertainties and predict the probability density distribution of the performance parameters. A detailed sensitivity analysis is performed to mine the correlations between uncertain variables and performance parameters, which are visualized through the self-organizing mapping. Furthermore, a flow field analysis is conducted to investigate the mechanism of uncertain variables affecting the performance. An energy equation-based approach is adopted to explore the energy transfer and conversion process. The results indicate that coupled uncertainty exacerbates performance fluctuations, and geometric uncertainty is the dominant factor of the performance deterioration. Operational uncertainties show a more pronounced correlation with response performance than geometric uncertainties. Additionally, from the perspective of energy decomposition and conversion, the variation in compressor aerodynamic performance may be basically due to more conversion between internal energy and transverse kinetic energy.& COPY; 2023 Elsevier Masson SAS. All rights reserved.