急拡大ノズルの空気噴出時におけるスクリーチ音の抑制

概要

論文の詳細を見る
An experimental study was made of the air flow noise generated by a nozzle with a sudden enlargement in the cross-section. Such nozzle shows a characteristic phenomenon that the A-weighted sound pressure level takes a minimum at a specified pressure of supplied air and generates a high intensity noise with a high frequency, screech noise, around the pressure. The screech noise gives a significant displeasure to a person handling the nozzle. The purpose of the study is to develop the preventive method against screech noise by air flow control, since the noise is closely related to the flow condition through the nozzle. It was found that the effective method was to protrude the nozzle into an enlarged region, or to make small holes in the wall of the region. The mechanism of the noise generation was also investigated and a design chart was prepared for the optimum nozzle geometry for the noise reduction.
社団法人日本音響学会の論文
1984-08-01