Experimental investigation of pressure pulsation induced by the floor-attached vortex in an axial flow pump

Abstract

The pressure pulsation test in an axial flow pump with and without the floor-attached vortex was performed. Pressure sensors were mounted on the impeller inlet section and impeller outlet section and guide vane section outlet of the axial flow pump. The investigations showed that the pressure pulsation in the axial flow pump was mainly affected by the impeller rotation. The time-domain characteristic curves of the pressure pulsation at the impeller inlet and outlet changed the most at different periods when the floor-attached vortex appeared in the pump sump. There was no significant difference between the time-domain characteristic curves of the pressure pulsation with and without the floor-attached vortex at the guide vane outlet. The pressure pulsation induced by the floor-attached vortex was a low-frequency pulsation of 2.12 Hz, which fluctuates periodically with time in the form of a trigonometric function. The pressure pulsation amplitudes with the floor-attached vortex were larger than those without the floor-attached vortex. The floor-attached vortex mainly affected the pressure pulsation in the impeller and had less influence on the pressure pulsation at the guide vane outlet due to the rectifying effect of the guide vane.