Effects of Reynolds Number on Performance of Highly Loaded Multi-Stage Axial Compressors

The influence of Reynolds number on performance of a highly loaded 10-stage axial compressor has been experimentally investigated. The experiment was performed by applying different inlet Reynolds numbers at several operating speeds. Reynolds number variation was achieved by throttling the inlet pressure. Both compressor total aerodynamic characteristics and detailed single stage performance were measured and analyzed. Test results show that all the compressor performance parameters including efficiency, mass flow and pressure ratio are reduced by decreasing Reynolds number. And the influence is higher at lower operating speed. Regarding to single stage characteristics, stage matching is less affected by Reynolds number at design speed, while all single stage chics are changed at low speed. The correlation between Reynolds number and compressor performance was obtained. Then the Wassell semi-empirical correlation method was applied to predict the Reynolds number influences for the same compressor. Comparison was made between experimental results and calculating results based on Wassell correlation. Results indicate that Wassell correlation is reliable for predicting trends. Wassell correlation works well for efficiency at design speed, but providing calculating inaccuracy at low speed. For mass flow correlation, Wassell correlation overestimated the influence of Reynolds number. Test results from this compressor are added to Wassell correlation curve, that provide reference for modern design application.