STEADY AND UNSTEADY SIMULATION OF THE FLOW INSIDE A CENTRIFUGAL COMPRESSOR STAGE

摘要

Computational investigations on a centrifugal compressor stage are presented to study unsteady interaction flow between the impeller and its vaned diffuser. Unsteady and steady calculations are compared with the measurement at different positions inside the diffuser. The influence of the impeller-diffuser interaction on the flow fields is discussed. Results show that qualitative and quite fair quantitative agreements are achieved between the unsteady predicted and measured flow fields. The interaction between the impeller and vaned diffuser can significantly change the calculated static pressure ratio and isentropic efficiency. The analysis shows that the unsteady interaction induces great change for the pressure on the diffuser vane and inlet flow condition and weakens quickly as radial increasing.