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Acoustic characteristics of large-scale stol model at forward speed
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Koenig, D. G. Aoyagi, K. Falarski, M. D. |
| Copyright Year | 1972 |
| Description | Wind-tunnel investigations of the acoustic characteristics of the externally blown jet flap (EBF) and augmentor wing STOL concepts are dicussed. The large-scale EBF model was equipped with a triple-slotted blown by four JT15D turbofan engines with circular, coannular exhaust nozzles. The large-scale augmentor wing model was equipped with an unlined augmentor blown by a slot primary nozzle. The effects of airspeed and angle of attack on the acoustics of the EBF were small. At a forward speed of 60 knots, the impingement noise of the landing flap was approximately 2 db lower than in the static tests. Angle of attack increased the impingement noise approximately 0.1 decibels per degree. Flap deflection had a greater effect on the acoustics of the augmentor wing than did airspeed. For a nozzle pressure ratio of 1.9, the peak perceived noise level of the landing flap was 3 to 5 PNdb higher than that of the takeoff flap. The total sound power was also significantly higher for landing indicating that turning in the augmentor generated acoustic energy. Airspeed produced a small aft shift in acoustic directivity with no significant change in the peak perceived noise levels or sound power levels. |
| File Size | 701759 |
| Page Count | 13 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19730013197 |
| Archival Resource Key | ark:/13960/t45q9pq18 |
| Language | English |
| Publisher Date | 1972-10-01 |
| Access Restriction | Open |
| Subject Keyword | Aircraft Externally Blown Flaps Acoustic Measurement Acoustic Properties Aerodynamic Configurations Aerodynamic Noise Wind Tunnel Models Short Takeoff Aircraft Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
