The Study on the Flow in a Horizontal Pump by 3D-PIV Experiments

In order to investigate the flow conditions in a horizontal open pump sump, and to validate chest wall with different angles on preventing the vortex, and to find the key factor to the entrained vortex generating from the free surface, 3D PIV experiments were carried out in the pump sump. In the research, 3D PIV system was used to measure the flow near the free surface in the sump with different chest wall with angle of 0° and 30°. In the research, the refractivity-revised method was applied to get clear images in different media. In the method, an accessory device was used to eliminate the refractive effect between air and water. In the experiments, the multi-step calibrated method was applied to improve the measurement precision of the W vector. For each kind of chest wall, the experiments were performed under three operation conditions with different flow rates. From the experiments, the 3D flow conditions on the measuring plane can be obtained, such as velocity, streamline, and W velocity component. Analyzing those results, it can be concluded that the chest wall with angle of 30° can improve the flow conditions obviously and weaken the entrained vortex flow in the sump. Analyzing the experimental results, it can be found that the entrained vortex are more depended on ratio of the W velocity to the total velocity than other factors.