Abstract
In order to clarify the mechanism of sound generation,flow fields and sound fields around a sphere placed in a uniform flow were investigated with a numerical simulation.The possibility of the noise control was also studied.The influence on sound fields of noise fields was tested and sound field can be controlled by using the particle-velocity of the sound.The noise from high-mode structure is reduced with the sound excitation.At that time,the sound level of the fundamental frequency of the Low-mode is increasing.
