Study on cavitating flows around an axisymmetric body with cavitators

The structure of cavitating flows around an axisymmetric body with different size cavitators is studied by experimental and numerical simulation methods. Cavity shapes around the body were obtained by a high-speed video camera in different cavitation numbers, and the time-averaged velocity, and time-averaged vorticity distributions were obtained by a digital particle image velocimetry (DPIV) system. The results show that the cavitator diameter has important influence on cavitating flows around the axisymmetric body. The inception cavitation number varies with the cavitator diameters in natural cavitation conditions. The bigger the cavitator diameter is, the larger the inception cavitation number is, and the more favorable to the cavity development. In ventilated cavitation conditions and the same ventilated rates, the cavity length around the axisymmetric body with a small cavitator is bigger than that of the axisymmetric body with a large cavitator. However, the supercavitating state is easily obtained in a lager cavitation number around the axisymmetric body with a small cavitator because the flow separation is obvious in the rear of large cavitator and there exists a more complicated vortex movement, which is not conducive to the formation of steady large cavity. At the same ventilated rate and Froude number, the cavitation shapes around the axisymmetric body with different diameters are different, and the fall-off mode and the period are different.