Abstract: The particle image velocimetry(PIV) was applied to investigate the different flow patterns of three low specific speed centrifugal pump impeller with deviated short splitter vanes. At design load, maximum load and minimum load, the internal flow fields have been obtained respectively and the distributions of relative velocity have alse been revealed. The measurement result shows that the influence on flow fields is significant for three deviated short vane schemes. While the inlets of short splitter vanes rotate to the pressure sides of long vanes related to the outlets, the distribution of relative velocity near the outlet of impeller passage is not uniform and a low velocity zone exists in the vicinity of the outlet of short vane working side. On the contrary, if the inlets of short splitter vanes rotate to the suction sides of long vanes, the relative velocity near the outlet is well-distributed and its water head and flux curves move right, the efficiency of the pump obviously rises up in accordance with large discharge quantity.

Key words: Centrifugal pump, Impeller with long and short vanes, Particle image velocimetry measurement