Samenvatting
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.
| Originele taal-2 | Engels |
|---|---|
| Titel | 5th AIAA/CEAS Aeroacoustics Conference and Exhibit |
| Uitgeverij | American Institute of Aeronautics and Astronautics Inc. (AIAA) |
| Pagina's | 140-150 |
| Aantal pagina's | 11 |
| DOI's | |
| Status | Gepubliceerd - 1999 |
| Evenement | Aeroacoustics Conference and Exhibit, AIAA/CEAS 1999 - Bellevue, Verenigde Staten van Amerika Duur: 10 mei 1999 → 12 mei 1999 |
Congres
| Congres | Aeroacoustics Conference and Exhibit, AIAA/CEAS 1999 |
|---|---|
| Land/Regio | Verenigde Staten van Amerika |
| Stad | Bellevue |
| Periode | 10/05/99 → 12/05/99 |
Financiering
Acknowledgement contribution of Professor Eversman was supported by NASA Lewis Research under Grant NAG 3-2109.