Hydraulic model testing of pump sumps

Abstract

The modelling of pump sumps for vortex formation is the focus of this paper. A physical hydraulic model of a large filtered water pumping station at Happy Valley reservoir in southern Adelaide was constructed and tested in 1988. The results and phases of the model test are described. The pumping station has three open sumps. The model scale was 1:10.463. The objective of the model study was to identify and eliminate any vortex formation or excessive swirl in order to maximise the efficiency of pump operation. A parametric study of a number of flow modification elements was carried out. Examples of elements included back splitters, floor splitters, surface beams, screens and fillets. Modifications were also made to the approach chamber leading to the sumps. Eight phases of model testing were performed. The relative effectiveness of various flow modification elements for swirl angle reduction and vortex elimination is summarised. The outcome of the model study was a design that performed satisfactorily with no vortex formation and small swirl angles in each sump. In addition a considerable savings in capital cost was achieved by a significant shortening of the pumping station.