Compressor-Surge Behaviors Distinguished Between Near-resonant Type and Convective Type

Abstract

In deep surges in compressors, the behaviors tend to show either a near-resonant one or a convective one, the latter performing emptying and filling actions. However, detailed information on the differences between them have not been obtained so far. In order to understand the situations, surge simulations by a one-dimensional simulation code were conducted with respect to a single-stage centrifugal compressor, paying attention to the effects of changes in the compressor tip speed and in the geometry of the flowpaths. As the results, it has been found that near-resonant surges appear at very low tip speeds and for relatively narrow sectional areas of the delivery flowpath, and they transform to convective surges of emptying and filling actions toward higher speeds and wider sectional areas. The features of the behaviors are generalized in terms of several non-dimensional surge frequency parameters. The results are visualized by several global framework maps showing the relations among the parameters. The obtained results will give deeper understandings on the surge phenomena.