The efects of forward speed on the noise of under-the-wing (externally blown flaps, EBF) and over-the-wing (upper surface blown, USB) blown flap configurations were measured in wind tunnel model tests with cold jets. The results are presented without correction for the effects (e.g. signal convection,shear layer refraction) associated with flight simulation in a wind tunnel or free jet facility. Noise decreases were generally observed at microphones forward of the wing. The reductions were larger at the low frequencies (below peak SPL) than at the high (above peak SPL). Noise increases of 10 dB or more were observed at the aft microphones, especially in the high frequency range. (Kursetz)
Forward speed effects on blown flap noise
Auswirkung der vorwaerts gerichteten Geschwindigkeit auf die Geraeuschentwicklung von Tragfluegelklappen
AIAA-Papers ; 1-8
1977
8 Seiten, 14 Bilder, 2 Tabellen, 9 Quellen
Conference paper
English
Forward speed effects on blown flap noise
AIAA | 1977
|Forward Flight Effects on Externally Blown Flap Noise
AIAA | 1978
|NTRS | 1972
|