On the effect of swirling motion of sources on subsonic jet noise

✍ Scribed by H.K. Tanna

• Publisher: Elsevier Science
• Year: 1973
• Tongue: English
• Weight: 640 KB
• Volume: 29
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1016/s0022-460x(73)80285-8

✦ Synopsis

This paper is a theoretical study of the effect of swirling motion of sources on the overall sound radiation from a subsonic jet. The general result for the sound field of a point acoustic stress in arbitrary motion is first applied to study the effect of uniform circular source motion on the far-field sound radiation from a randomly orientated point quadrupole of random time variation. By using the moving source approach, closed form results are obtained for the overall radiation directly, without !nvolving the radiation spectrum. A uniform axial motion is then superimposed and the sound field of a point quadrupole in helical motion is evaluated by applying retarded time transformations to the circular motion results. The effects of acceleration of the sources, due to steady convection in a helical path, on the familiar linear motion results for subsonic jet noise are established. Finally, some relevant comments on the application of the theory are presented.