抄録
Cavitating water jets have been successfully applied in fields of engineering, such as cutting, cleaning, peenings and so on. The erosion ability of the jets is considerably affected by the nozzle geometry. Thus, clarification of the behavior of cavities formed by submerged water jets is considered to be one of the most useful methods for clarifying the mechanism of erosion for the nozzle geometry. We systematically analyzed the cavity area and the cavity width with respect to time and standoff distance for two nozzle geometry, i. e. a cylindrical nozzle and a conical nozzle. The cavity changes successively markedly in length, in area, in width in the periodic process of the cavity, such as the growth, the shedding and the collapse. The fluctuating amplitude of the cavity length for the cylindrical nozzle is higher than that for the conical nozzle. In short, the erosion ability depends greatly on the unsteady behavior resulting from the nozzle geometry, and for the cylindrical nozzle, the ability is comparatively high.
