ultrasonic cavitation, hydraulic tank, hydrodynamic cavitation, gear pump, plastic, PIV-visualization, Mechanics of engineering. Applied mechanics, TA349-359

The article describes the course of the ultrasonic cavitation in a hydraulic tank and the hydrodynamic cavitation in a gear pump. The course of those phenomena was confirmed in experimental tests carried out with the use of a tank and a pump made of transparent plastics. It has been proved that the oscillator-cavitation system made according to the original project is useful to induce the phenomenon of ultrasonic cavitation. It has also been shown that the PIV visualization method, consisting in a special system of illuminating transparent objects and recording the flow through those objects with a fast camera, is useful for the studying of the cavitation phenomena. A visible interaction between the ultrasonic and the hydrodynamic cavitation was observed. The induction of ultrasonic cavitation in the tank causes degassing of the oil, and the degassed oil supplying the pump reduces the hydrodynamic cavitation in its internal channels and clearances. This is an example of beneficial effects of the ultrasonic cavitation on the operation of a pump and a hydraulic system. The presented work is an example of effective co-operation between the communities of Wroclaw University of Science and Technology and Igor Sikorsky Kiyv Politechnic Institute, National Technical University of Ukraine.