Cavitation field from a horn—A new model

The cavitation field from a horn-type transducer is experimentally probed by the optical method. Based on these observations, we propose a model of the field which hypothesizes that most violent caviation bubbles originate from the vibrating surface and there-from fast drift to the near liquid region. These bubbles are chiefly responsible for the practical applications of cavitation for a large power input to the transducer. During migration they become weakened. Cavitation bubbles are also produced in the liquid region by the acoustic wave directly emitted by the transducer, but these bubbles are weak due to the shielding effect of the bubbles clinging to the transducer vibrating surface. Consequently, only weak cavitation bubbles exist in the far liquid region.