Numerical Study of the Improvement in Stability and Performance by Use of a Partial Vaned Diffuser for a Centrifugal Compressor Stage

The influence of different diffuser configurations on the flow stability and aerodynamic performance a centrifugal compressor stage with mass coefficient 0.196 is numerically investigated. Research results show that traditional full-height vaned (TVD) deteriorates rapidly, shroud-side partial (SVD) displays better adaptability in off-design conditions. SVD can suppress development vortices generating at leading-edge. Therefore, it reduce loss inside improve low rates. unsteady analysis for TVD shows stall cell propagates about 35.7% impeller rotational speed semi-vaneless space passages. Furthermore, internal studied by employing proper orthogonal decomposition (POD) dynamic mode (DMD) methods. instability mechanism are consequently revealed more comprehensively.