Experiment of the flow field at the outlet of impeller of axial-flow pump

The flow field at the outlet of impeller in the designed axial-flow pump was measured by using the five-hole probe. Three velocity components and circulation curves were obtained. The measured results show that the flow field at the outlet of impeller is a spiral movement. Under the optimum condition, the rotary kinetic energy occupies 34% of the total outlet kinetic energy and decreases with the increase of the flux. Accompanied by the small radial velocity, the axial velocity increases with the flow intensifying. The velocity circulation decrease from the hub to the flange, wherefore the more circular velocity at the flange and the less at the hub are needed. The 3-D velocity distribution of flow field can be measured accurately by the probe. This method has the merits of simple operation and well applicability.