Analysis of CFD Modeling Accuracy in Centrifugal Compressor Stages Digital Twins

Obtained and discussed results of comparison of the experimental gas-dynamic characteristics of the 12 centrifugal compressor stages with the 3D impellers the results of numerical simulation of three-dimensional viscous flow (CFD). Impellers, accepted for study, have different design values of the coefficients of the theoretical head, coefficient of the condition flow and the values of the design diffusivity flow expressed by the ratio b₂/D₂. The simulation was performed using the SST turbulence model. Based on the simulation results, the gas-dynamic characteristics of the internal, theoretical, polytrophic head coefficients and polytrophic efficiency are calculated in total to total parameters. All calculations are characterized by moderate overestimation of the internal and polytrophic head coefficients relative to the experimental values, which indicates the presence of unaccounted losses in the simulation. It is recommended that the computational model be thoroughly tested and calibrated to determine the optimal qualitative and quantitative assessment. The estimation of the level of the arithmetic mean relative error of modeling in the zone of economical operation was carried out.