Study on the flow field in the vaned diffuser of a centrifugal compressor (CFD analysis with flow deviation at impeller exit)

摘要

Flow field in the vaned diffuser was calculated with CFD code at various compressor operating points. Impeller discharge total pressure and flow angle, which were measured with a 3-hole yaw probe, were used as the inlet boundary condition for the calculations. We investigated the variation of the pressure recovery factor, total pressure loss coefficient and blockage factor from choke flow rate to surge flow rate with the calculated results. The calculated results also showed the strong secondary flow, which was caused by the flow angle distribution at the diffuser inlet, would energize the flow near shroud and restrain the separation near shroud.