Abstract
This paper is concerned with the mechanism of sound generation from bubbles, which are entrained by a steady water film flow plunging into a still water surface. It is clarified that the bubbles are entrained intermittently by the steady plunging flow and that their entrainment is governed by velocity fluctuations of the flow. The amplitude of sound pressure generated by bubbles attains a maximum just after the entrainment, and the sound source is bubbles situated in the neighborhood of the water surface. The number of entrained bubbles and the sound pressure increase in a turbulent state compared to a laminar one with the same mean velocity.
