ENBIS-18 in Nancy
2 – 25 September 2018; Ecoles des Mines, Nancy (France)
Abstract submission: 20 December 2017 – 4 June 2018
Sensitivity Analysis and Constrained Multiobjective Optimization of Computer Experiments: A Case Study of a Centrifugal Compressor Impeller
3 September 2018, 14:20 – 14:40
- Submitted by
- Sonja Kuhnt
- Sonja Kuhnt (Dortmund University of Applied Sciences and Arts)
- Computer simulations often replace real-life experiments in engineering and natural sciences nowadays. For the whole process chain of energy transformation, turbo machines play an important role. Centrifugal compressor impellers are a vital part of turbo machines. In our application, a specific impeller geometry is simulated over the entire operating range with regard to its efficiency. As the simulations are very time-consuming and complex, we built meta-models and base sensitivity analysis and optimization on them. Gaussian process models, better known as Kriging models, are a common choice.
Sensitivity analysis investigates how the input variables contribute to the variation of the outcome. A popular method is the use of Sobol indices which quantify the importance of individual input variables or groups of them. We review the Sobol sensitivity indices and the more recently developed total interaction indices (TII) and show how to display them in so-called FANOVA graphs. Besides increasing the knowledge about the unknown black-box function, results from sensitivity analysis are useful within modeling and optimization.
When searching for a global optimum, the well-known efficient global optimization (EGO) procedure considers prediction values as well as the model uncertainty. The compressor impeller application requires the optimization of multiple responses under additional constraints. We apply and compare possible extensions of the EGO algorithm.
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