抄録
The effect of the shape of intake in a vertical pump on the pump performance is investigated experimentally. The velocity around the intake of the pump is measured by using LDV (Laser Doppler Velocimetry) and the flow field is visualized when the pump is operated at the specified capacity. We investigate the relation between the velocity distribution around the intake and the pump performance. It is found that an appearance of a retard region, which develops due to a flow separation at the edge of intake, reduces the pump performance. If the intake has an enough extent, the retarded region is suppressed because the flow separation does not develop. Hence, we determined the minimum expansion rate in the shape of the intake where the pump performance is not affected significantly.
