Extension of the near acoustic field of a jet to the far field

The problem of extending the near acoustic field of a high-speed jet to the far field is considered. This is akin to the problem of analytic continuation in complex variable. Analytic continuation is the extension of an analytic function in a limited domain to a larger domain. The general continuation problem involving acoustic sources enclosed by a surface is first analyzed. It is shown that a unique continuation to the far field is possible provided either the pressure or the pressure gradient normal to the surface is given on the surface. In this paper, the continuation is carried out by means of an adjoint Green’s function. One significant advantage of using adjoint Green’s function is that for a given direction of radiation, one is required to solve only a single acoustic scattering problem. Because the present method requires measuring only the fluctuation pressure on the bounding surface whereas other popular methods such as the Kirchhoff integral method or the Ffowcs-Williams and Hawkings equation requires measuring three or more variables, it appears that the present method has definite advantage when it is used to extend an experimentally measured near acoustic field to the far field.

• Record URL:
  • https://doi.org/10.1016/j.proeng.2010.09.002
• Record URL:
  • http://www.sciencedirect.com/science/article/pii/S1877705810005485
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/18777058
• Supplemental Notes:
  • © 2010 Published by Elsevier Ltd.
• Authors:
  • Tam, Christopher K W
  • Pastouchenko, Nikolai N
  • Viswanathan, K
• Conference:
  • IUTAM Symposium on Computational Aero-Acoustics for Aircraft Noise Prediction
  • Location: Southampton , United Kingdom
  • Date: 2010-3-29 to 2010-3-31
• Publication Date: 2010

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References;
• Pagination: pp 9-18
• Serial:
  • Procedia Engineering
  • Volume: 6
  • Issue Number: 0
  • Publisher: Elsevier
  • ISSN: 1877-7058
  • Serial URL: http://www.sciencedirect.com/science/journal/18777058
• Publication flags:

  Open Access (libre)

Subject/Index Terms

• TRT Terms: Acoustic emission; Aircraft noise; Far field; Green's function; Jet propelled aircraft; Near field
• Uncontrolled Terms: Computational aeroacoustics
• Subject Areas: Aviation; Environment; Vehicles and Equipment;

Filing Info

• Accession Number: 01615630
• Record Type: Publication
• Files: TRIS
• Created Date: Oct 31 2016 11:42AM