Throughflow Analysis of a Multistage Compressor Operating at Near-Stall Conditions

Abstract

Because of their speed and efficiency, two–dimensional steady flow calculations will continue to play a significant role in the compressor aerodynamic design process. For this reason, an assessment of throughflow theory was undertaken based on detailed measurements obtained in a large-scale rotating compressor rig. This assessment is focused specifically on the compressor aerodynamics at near-stall conditions, since the three dimensionality of the flow is at its worst under these circumstances and the assumptions of axisymmetry in the theory will be tested far more severely than at design conditions. This assessment demonstrates that a reasonably accurate prediction can be achieved but that major discrepancies can occur near the endwalls where blockage is high. It has also been demonstrated that large errors can be incurred when the spanwise description of blockage is inaccurate in its detailed distribution or in its level.