Measurement and analysis of three-dimensional flows in the volute of a centrifugal compressor with a round section

By utilizing a five-hole probe, measured in detail were three-dimensional flows in the volute of a large-sized low-speed centrifugal compressor with a round section. As a result, a flow velocity distribution and a distribution chart of flow speed, total and static pressure along the radial and circumferential direction in the radial measurement section of the spiral flow passage portion of the volute were given, and the flow rates thus obtained, compared with those obtained from the one-dimensional calculation. It has been found that the measured flow rates in various sections assume an identical variation tendency with those obtained from the one-dimensional calculation. In step with increasing angles, the difference between the calculation results and test ones gradually decreases. In addition, the flows in the volute under test pertain to complex three-dimensional flows, and the flow speed distribution along the radial direction in various radial sections of the volute features a comparatively conspicuous difference from the momentum conservation law. The change in total pressures along the circumferential direction is not manifest.