平板と楔による狭い隙間流れから発生する離散周波数騒音について

概要

論文の詳細を見る
Aerodynamic noise with discrete frequencies is generated in an unexpected way from a slit between a flat plate, which is placed in parallel to the main flow, and a wedge that is placed normal to the flow. To study this phenomenon, we examined the discrete frequency noise generated by a subsonic air jet flow from a slit. It was found that the slit height and the plate length have considerable effects on the noise generation. In addition, the discrete frequency noise was generated only when the values of these parameters are within a limited range. Furthermore, it was found that the noise frequency is proportional to the jet velocity and is inversely proportional to the plate length. Finally, it was made clear from the present study that the interaction of the vortex, which is generated from the shear layer due to a wedge, with the wake of a flat plate is a major cause for the discrete noise due to a slit.