気泡を含む水流中の衝撃雑音の測定

概要

論文の詳細を見る
In this research work, it is clarified that mechanism of impulsive noise generation in a bubbly water flow by a solid wall or by something in it is caused by the separation of large bubbles and that the damping oscillation waveform of impulsive noise is caused by the pulsating oscillation of the separated small bubbles. In the bubbly water flow of up to 4m/s, the frequency of impulsive generation and the peak value of the noise amplitude become larger, as the flow velocity increases. The peak value of the impulsive noise, however, is at most 30kPa, and the value is very small in comparison with that of cavitation noise. The frequency of impulsive noise generation changes greately with the bubbly flow velocity. In case of the velocity of about 1. 5m/s, it is about one hundredth of the value at the velocity of 4m/s. When the bubbly water flow velocity is under 2. 5m/s, the occurrence of impulsive noise whose peak value is above 10kPa bacomes less than once per second, and it becomes negligible in comparison with that of impulsive noise whose peak value is around 3kPa.
社団法人日本音響学会の論文
1983-11-01