Abstract
The unsteady noise related to bubbles in a drain pipe connected to a water tank was investigated experimentally. The noise consisted of two different characteristics noises, that is, the noises due to separation of bubbles from air column and formation of a large cavity on upper surface of the drain pipe. These two types of bubbles were investigated by flow visualization by using a high speed camera and noise was measured by a directional microphone. These results are presented in this paper.
