Experimental investigation on the performance of improving jet pump cavitation with air suction

• A new method of inhaling air to improve the jet pump cavitation is proposed.
• Cavitation number increases with the air suction quantity increasing linearly.
• Acoustic noise and pressure fluctuation reduce in the jet pump downstream.
• Air suction is more effective on improving the severe cavitation.
• Air suction reduces the pressure loss and increases the pressure ratio.

In order to improve the jet pump cavitation, a new method of inhaling air into the low-pressure region was proposed, and its performance was investigated experimentally under different air suction quantity and cavitation levels. Test results show that the cavitation number increases with the air suction quantity increasing in a linear approximation fashion. Increasing air suction quantity corresponds to a sharp decrease in acoustic noise, especially for the severe cavitation. As the air suction quantity increases, the pressure fluctuation range and fluctuation variance both decrease in the downstream, which relieve the cavitation vibration damage and enhance the jet pump stability. In addition, the pressure loss ratio reduces by 0.95%–3.46% and the pressure ratio increases by 5.7%–18% due to the water–air cushion layer formed in the wall boundary. The marked effect on preventing cavitation damage and improving the pressure transmission performance of the jet pump proves that the new air suction method proposed is practical and effective. Therefore, it is believed that this study would lay an important foundation for the widespread application of jet pump in the future.