Loading...
Please wait, while we are loading the content...
Similar Documents
Detailed noise measurements on the sr-7a propeller: tone behavior with helical tip mach number
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Dittmar, James H. Hall, David G. |
| Copyright Year | 1991 |
| Description | Detailed noise measurements were taken on the SR-7A propeller to investigate the behavior of the noise with helical tip Mach number and then to level off as Mach number was increased further. This behavior was further investigated by obtaining detailed pressure-time histories of data. The pressure-time histories indicate that a portion of the primary pressure pulse is progressively cancelled by a secondary pulse which results in the noise leveling off as the helical tip Mach number is increased. This second pulse appears to originate on the same blade as the primary pulse and is in some way connected to the blade itself. This leaves open the possibility of redesigning the blade to improve the cancellation; thereby, the propeller noise is reduced. |
| File Size | 9907884 |
| Page Count | 31 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19920007487 |
| Archival Resource Key | ark:/13960/t8gf5qh23 |
| Language | English |
| Publisher Date | 1991-12-01 |
| Access Restriction | Open |
| Subject Keyword | Acoustics Propeller Blades Blade Tips Engine Design Supersonic Speed Propeller Noise Turboprop Engines Noise Measurement Mach Number Tip Speed 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 |
