The major problem in the design of a low-noise supersonic wind tunnel is to reduce the noise radiated from the turbulent, nozzle-wall boundary layer. This broadband noise is generally the dominant disturbance mode in the wind tunnels at Mach numbers greater than about 2.5. These acoustic disturbances are propagated along Mach lines in supersonic flow; hence, their sources are located far upstream of the test section at so-called 'acoustic origins' near the nozzle wall. It is shown that tailoring the nozzle contour to reduce the Mach number and boundary-layer thickness at the acoustic origins significantly reduces the noise levels in the upstream part of the test rhombus. (Jensen)
New technique for reducing test section noise in supersonic wind tunnels
Neue Technik zur Laermminderung an Pruefteilen in Ueberschallwindkanaelen
AIAA Journal ; 18 , 1 ; 5-6
1980
2 Seiten, 2 Bilder, 11 Quellen
Article (Journal)
English
Aerodynamic noise in supersonic wind tunnels
NTRS | 1959
|Emerald Group Publishing | 1960
|Engineering Index Backfile | 1960
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