Abstract
This paper presents a basic study on similarity law of several shapes of the subsonic speed jet noise around 120m/sec. In this experiment, we paid attention to the influence of the aspect ratio and the R of the nozzle corner on the jet noise. Jet noises generated from several shapes of nozzle with the same opening area were evaluated by the similarity law. It was clarified that the main sound source radiated from the jet with the speed around 120m/sec was the di-pole source. Moreover, because the spectrum patterns of the generated sound are mainly affected by the sound field (that is shape of the object),it is supposed that the object influences the sound field by the reflection and the diffraction. In addition, the flat nozzle generated the lowest noise in our experiment.
