軸流ファンにおける低周波吸音について

抄録

The acoustic treatment with a rather large cavity was discussed from both aspects of analysis and experiment for low-frequency noise reduction in a low-speed axial flow fan. The rectangular and annular ducts with treatments were used. It is tentatively concluded that the axial modes of sound wave travelling in the cavity played an important role in low-frequency noise reduction mechanism. The acoustic treatment with a biased cavity showed a promise from a view point of weight reduction in aeroengines and fluid machinery.