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Radially leaned outlet guide vanes for fan source noise reduction
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Kazin, S. B. |
| Copyright Year | 1973 |
| Description | Two quiet engine program half scale fans one with a subsonic and the other with a supersonic fan tip speed at takeoff were run with 30 degree leaned and radial outlet guide vanes. Acoustic data at takeoff fan speed on the subsonic tip speed fan showed decreases in 200-foot sideline noise of from 1 to 2 PNdb. The supersonic tip speed fan a takeoff fan speed, however, showed noise increases of up 3 PNdb and a decrease in fan efficiency. At approach fan speed, the subsonic tip speed fan showed a noise decrease of 2.3 PNdb at the 200-foot sideline maximum angle and an increase in efficiency. The supersonic tip speed fan showed noise increase of 3.5 PNdb and no change in efficiency. The decrease in fan efficiency and the nature of the noise increase largely high frequency broadband noise lead to the speculation that an aerodynamic problem occurred. |
| File Size | 3748818 |
| Page Count | 87 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19740003484 |
| Archival Resource Key | ark:/13960/t5s804r8f |
| Language | English |
| Publisher Date | 1973-11-01 |
| Access Restriction | Open |
| Subject Keyword | Propulsion Systems Effective Perceived Noise Levels Broadband Noise Reduction Turbofans Aerodynamic Noise Acoustics Guide Vanes 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 |
