A numerical comparison between multiple-scales and eem solution for sound propagation s lined flow ducts

Sjoerd W. Rienstra, Walter Eversman

Research output: Contribution to conferencePaperAcademic

3 Citations (Scopus)

Abstract

An explicit, analytical, multiple-scales solution for modal sound transmission through slowly varying ducts with mean flow and acoustic lining, is tested against a numerically "exact" finite element solution. The test geometry taken is representative of a high-bypass turbo fan aircraft engine, with typical Mach numbers of 0.5-0.7, circumferential mode numbers m of 10-40, dimensionless-wave numbers of 10-50, and both hard and acoustically treated inlet walls of impedance Z = 2 - i. Of special interest is the presence of the spinner, which incorporates a geometrical complexity which could previously only be handled by fully numerical solutions. The results in predicted power attenuation loss show in general a very good agreement. The results in iso-pressure contour plots show good comparison in the cases where scattering into many higher radial modes can occur easily (high frequency, low angular mode), and again a very good agreement in the other cases.

Original languageEnglish
Pages140-150
Number of pages11
Publication statusPublished - 1999
EventAeroacoustics Conference and Exhibit, AIAA/CEAS 1999 - Bellevue, United States
Duration: 10 May 199912 May 1999

Conference

ConferenceAeroacoustics Conference and Exhibit, AIAA/CEAS 1999
Country/TerritoryUnited States
CityBellevue
Period10/05/9912/05/99

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