Abstract
The spray atomization has been believed to be enhanced by various mechanisms such as internal flow disturbance caused by existence of cavitation bubbles and shock wave generated by bubble collapse. This report focuses on the shock wave generated when the bubble collapses. As the first stage, the quantity of dissolved air was changed, which played an important role for the nucleus of cavitation bubbles. Cavitation images were obtained by a high speed video camera and the pressure distribution in the throat of the orifice were measured by a manometer. Moreover, the impact acceleration of the bubble collapses was measured with an acceleration sensor. A comparison between the influence of dissolved air quantity and the degree of the shock wave was carried out. As a result, the impact acceleration becomes larger by decreasing the dissolved air quantity, whereas there is no changed in pressure distribution in the throat of the orifice.
