The performance of centrifugal compressors can be seriously affected by inlet flow distortion that is by non-uniform inlet flow. The distortion can be in static pressure or stagnation temperature, but the most common distortion is stagnation pressure. Such distortions often occur because of the unsatisfactory nature of the inlet configuration and the resulting inlet flow structure.
In this current work, Part I of two parts, experimental test has been carried out for the comparison of a centrifugal compressor stage efficiency with two different inlet configurations, one of which is straight with constant area and the other is a 90-degree curved pipe with nozzle shape as inlet models. The comparative result from the test showed significant stage efficiency difference between the two different inlet configurations. The result is analyzed and attempt is made to understand the flow structure caused by each type of configuration and the resulting effect on the performance of the stage.