To investigate the stall improvement mechanism of vaneless diffuser flow path control

a centrifugal compressor was simulated and compared with existing experimental data.According to characteristics of flow field and stall mechanism

a convergent-divergent type of impeller-diffuser casing designed was analyzed.The result shows that the stable flow range of centrifugal compressor increases by 2.8%

however

no obvious positive effects are found on the adiabatic efficiency which is slightly lower than that of the prototype.