Fig. 3.

Key elements of the test rig: 1 – RGHC, 2 – phase asynchronous motor, controlled by variable frequency drive, 3 – pressure side throttling valve, 4 – 1000 L tank, 5 – suction side throttling valve, 6 – discharge valve. Installed measurement equipment: a – absolute pressure transducer, b – differential pressure transducer, c – electromagnetic flow meter, d – hydrophone, e – high-speed camera.