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An Investigation of Two Acoustic Propagation Codes for Three-Dimensional GeometriesThe ability to predict fan noise within complex three-dimensional aircraft engine nacelle geometries is a valuable tool in studying low-noise designs. Recent years have seen the development of aeroacoustic propagation codes using various levels of approximation to obtain such a capability. In light of this, it is beneficial to pursue a design paradigm that incorporates the strengths of the various tools. The development of a quasi-3D methodology (Q3D-FEM) at NASA Langley has brought these ideas to mind in relation to the framework of the CDUCT-LaRC acoustic propagation and radiation tool. As more extensive three dimensional codes become available, it would seem appropriate to incorporate these tools into a framework similar to CDUCT-LaRC and use them in a complementary manner. This work focuses on such an approach in beginning the steps toward a systematic assessment of the errors, and hence the trade-offs, involved in the use of these codes. To illustrate this point, CDUCT-LaRC was used to study benchmark hardwall duct problems to quantify errors caused by wave propagation in directions far removed from that defined by the parabolic approximation. Configurations incorporating acoustic treatment were also studied with CDUCT-LaRC and Q3D-FEM. The cases presented show that acoustic treatment diminishes the effects of CDUCT-LaRC phase error as the solutions are attenuated. The results of the Q3D-FEM were very promising and matched the analytic solution very well. Overall, these tests were meant to serve as a step toward the systematic study of errors inherent in the propagation module of CDUCT-LaRC, as well as an initial test of the higher fidelity Q3D-FEM code.
Document ID
20050182053
Acquisition Source
Langley Research Center
Document Type
Preprint (Draft being sent to journal)
Authors
Nark, D. M.
(NASA Langley Research Center Hampton, VA, United States)
Watson, W. R.
(NASA Langley Research Center Hampton, VA, United States)
Jones, M. G.
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
September 7, 2013
Publication Date
January 1, 2005
Subject Category
Acoustics
Report/Patent Number
AIAA Paper 2005-3022
Meeting Information
Meeting: 11th AIAA CEAS Aeroacoustics Conference
Location: Monterey, CA
Country: United States
Start Date: May 23, 2005
End Date: May 25, 2005
Sponsors: Confederation of European Aerospace Societies, American Inst. of Aeronautics and Astronautics
Funding Number(s)
OTHER: 23-781-30-14
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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