Effect of the Submerged Vortex Cavitation Occurred in Pump Suction Intake on Hydraulic Forces of Mixed Flow Pump Impeller

The effect of submerged vortices on the hydraulic forces of a mixed flow pump impeller was studied using a model pump with an intake sump. The experiments comprise observation of submerged vortices reaching the impeller with a high-speed video camera and measurement of the velocity distribution around the submerged vortex by PTV (particle tracking velocimetry) to obtain the strength of the vortex. Measurement results are compared with CFD (computational fluid dynamics) calculation to evaluate their accuracy. Hydraulic forces on the model pump when the submerged vortex reached the pump impeller was measured with load cells. The relationship between the strength of the submerged vortex and the effect of the vortex on the fluctuation of the hydraulic forces are described