A study on the effectiveness of an anti vortex device in the sump model by experiment and CFD

The head-capacity curves of pumps developed by the pump manufacturer are based on tests of a single pump operation in a semi-infinite basin with no closed walls of floors and with no stray currents. Therefore, the flow into the pump intake has no vortices of swirling. However, pump station designers relying on these curves to define the operating conditions for the selected pump sometimes experience reductions in capacity and efficiency, as well as an increase of vibration and additional noise. Therefore, sump model testing is necessary in order to examine the flow structure around intake. In this study, flow uniformity according to the flow distribution in the pump intake channel is examined to find out the cause of vortex occurrence in detail by experiment and CFD. Furthermore, the effectiveness of an anti vortex device for the suppression of the vortex occurrence in a single intake pump sump model has been examined by AVD type. The AVDs used for experimental testing, one of which has the shape of a rectangular bar and the other was a trident shape, are attached at the bottom of pump intake channel just below the bell-mouth. The AVD type for CFD test is in the shape of a trident. The experimental sump model was scaled down by a ratio of 1:8 whereas the CFD sump model was scaled to the actual size.