2006 年 72 巻 720 号 p. 1952-1959
An experimental investigation has been carried out for the flow-induced sound in a grooved circular pipe. The length of the pipe is 500 mm, the inner diameter is 23 mm and the groove pitch is kept at 8 mm. The velocity in the pipe is varied from 6 m/s to 66 m/s. In the region of the velocity smaller than 30 m/s, the frequency of the sound generated in the pipe increases in the shape of stairs with increase of the velocity, and then resonant sound of the pipe generates from the pipe. When the velocity becomes large, the frequency of the sound increases linearly to the velocity. The shape of change of the frequency can be explained from characteristics of a cavity flow and lock-in phenomenon by the resonant frequency of the pipe.