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Acoustic and aerodynamic performance of a variable-pitch 1.83-meter-(6-ft) diameter 1.20-pressure-ratio fan stage (qf-9)
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Glaser, F. W. Lucas, J. G. Woodward, R. P. |
| Copyright Year | 1977 |
| Description | Far field noise data and related aerodynamic performance are presented for a variable pitch fan stage having characteristics suitable for low noise, STOL engine application. However, no acoustic suppression material was used in the flow passages. The fan was externally driven by an electric motor. Tests were made at several forward thrust rotor blade pitch angles and one for reverse thrust. Fan speed was varied from 60 to 120 percent of takeoff (design) speed, and exhaust nozzles having areas 92 to 105 percent of design were tested. The fan noise level was at a minimum at the design rotor blade pitch angles of 64 deg for takeoff thrust and at 57 deg for approach (50 percent takeoff thrust). Perceived noise along a 152.4-m sideline reached 100.1 PNdb for the takeoff (design) configuration for a stage pressure ratio of 1.17 and thrust of 57,600 N. For reverse thrust the PNL values were 4 to 5 PNdb above the takeoff values at comparable fan speeds. |
| File Size | 3063985 |
| Page Count | 69 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19770011107 |
| Archival Resource Key | ark:/13960/t28960f8w |
| Language | English |
| Publisher Date | 1977-02-01 |
| Access Restriction | Open |
| Subject Keyword | Aerodynamics Noise Propagation Effective Perceived Noise Levels Engine Noise Noise Reduction Turbofans Short Takeoff Aircraft Aircraft Engines Aerodynamic Characteristics Pitch Inclination Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
