Luminescent spots induced by a cavitating jet

As cavitation bubble collapses cause hot spots and/or radicals such as hydroxyl radical, luminescence was observed at bubble collapsing region. The luminescence induced by acoustic cavitation is named as sonoluminescence. In the present paper, luminescence induced by hydrodynamic cavitation was investigated. In order to generate hydrodynamic cavitation, a high-speed water jet was injected into a water-filled chamber. This sort of the jet with cavitation is called as a cavitating jet. The intensity of luminescence of the cavitating jet was evaluated by a luminescence analyzer and the aspect of the cavitating jet was observed by a cooled electron multiplication charged-coupled device camera. It was revealed that the luminescent spots induced by the cavitating jet were observed by the camera.