Performance modeling for a single-stage pipeline centrifugal compressor

The object of CFD calculations is a 1:2 model of a 32 MW single-stage pipeline compressor. The calculated
efficiency and pressure coefficient characteristics are compared with the characteristics measured at the test
rig of the design’s ordering customer. Comparative calculations are made for three interfaces coupling the
flow parameters of the rotating impeller to those of the stationary diffuser. Two of the interfaces treat the
flow as steady. The third interface represents the performance characteristics taking into account the
periodic unsteadiness. Four turbulence models are compared. The calculations of geometric models with
the number of cells differing by two times are compared. The geometric model in one of the calculation
variants includes a gap between the body and the shroud of the impeller. The calculation with the unsteady
state and flow in the gap between the body and the gap taken into account leads to better agreement between
the calculated and measured characteristics. The results of modeling are not satisfactory anyway.