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An experimental investigation of the interior noise control effects of propeller synchrophasing
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Fuller, C. R. Jones, J. D. |
| Copyright Year | 1986 |
| Description | A simplified cylindrical model of an aircraft fuselage is used to investigate the mechanisms of interior noise suppression using synchrophasing techniques. This investigation allows isolation of important parameters to define the characteristics of synchrophasing. The optimum synchrophase angle for maximum noise reduction is found for several interior microphone positions with pure tone source excitation. Noise reductions of up to 30 dB are shown for some microphone positions, however, overall reductions are less. A computer algorithm is developed to decompose the cylinder vibration into modal components over a wide range of synchrophase angles. The circumferential modal response of the shell vibration is shown to govern the transmission of sound into the cylinder rather than localized transmission. As well as investigating synchrophasing, the interior sound field due to sources typical of propellers has been measured and discussed. |
| File Size | 2647408 |
| Page Count | 102 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19870002144 |
| Archival Resource Key | ark:/13960/t3sv2gb5t |
| Language | English |
| Publisher Date | 1986-10-01 |
| Access Restriction | Open |
| Subject Keyword | Acoustics Propeller Blades Synchrophasing Algorithms Noise Reduction Aircraft Noise Modal Response Cylindrical Bodies Aircraft Compartments Fuselages Computer Programs Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
