Improving experiment data process accuracy for axial compressors: Converting inter-stage data into meridional flow fields

Abstract

The total temperature and pressure are measured as inter-stage data in axial compressor experiments. Traditional diagnosing methods of 0-dimension (0D) or 1-dimension (1D) could lead to higher errors at hub sections without the presence of the radial equilibrium equation at stator leading edges, and 3-dimensional computational fluid dynamics can hardly provide reliable results for multistage compressors. In this paper, a fast method called “Diagnosis Using Inter-stage Data” (DUID) was developed to convert experiment data into meridional flow fields, which automatically satisfies the radial equilibrium equation and provides more accurate results for axial compressors. An aeroengine fan, a 3-stage compressor and a 6-stage compressor were used to validate the DUID. Their meridional flow fields, which cannot be observed directly in test rigs, were rebuilt. Results reveal facts that hub static pressures are approximately 15% lower than the traditional 0D/1D constant assumption. Though the stator models determine the loss ratio in a single stage, the DUID can avoid the model error amplification and be robustious for multistage compressors. And the generated flow field is sensitive to changes in the total temperature. Analyses of the experiment flow fields provide more quantitative and accurate references for subsequent modifications. In conclusion, using experiment inter-stage data, the DUID can rebuild meridional flow fields, which help to improve data processing accuracy.