Physics-based surge point identification for unsupervised CFD-computation of centrifugal compressor speed lines

• Published in: Energy conversion and management. X 2023-01, Vol.17, p.100337, Article 100337
• Main Authors: Lattner, Yannick, Geller, Marius, Kutz, Michael
• Format: Article
• Language: English
• Subjects: Centrifugal compressor; Computational fluid dynamics; Optimization; Speed line; Surge; Turbomachinery
• ISSN: 2590-1745; 2590-1745
• DOI: 10.1016/j.ecmx.2022.100337

•Discussion of CFD-based surge identifiers for centrifugal compressors.•Convergence-based identification is not suitable for stochastic samples.•Temperature-based identification requires design-specific calibration.•Pressure-based identification offers precise and unsupervised speed line calculation.•The approach is applied to 50 compressor designs with 50 geometry variations each. We present a speed line calculation model using physics-based surge point identification. When using surrogate model-based design of experiment (DOE) techniques, the large number of computations demands an automated, unsupervised process to calculate the speed line and to identify its significant points. A high-fidelity CAE workflow is used to calculate the machine design, create the CAD geometry, generate a mesh, and prepare a CFD setup. The choke point, the surge point and the peak efficiency point are sequentially identified using sophisticated identifiers and optimization algorithms. The model was used to calculate the speed line of 50 different centrifugal compressor designs with 50 geometry variations each. From these 2,500 designs, 2,449 speed lines were calculated successfully, without specific settings having been assigned to individual designs. This proves that the model enables the stable, reproducible, reliable and effective CFD calculation of the speed line of centrifugal compressors.