An experimental study of a reattaching supersonic shear layer

A free-surface shear layer was studied to ascertain the effects due to the presence of surface tension gradients on the directional shift of the shear layer and turbulence intensities in the vicinity of the water free-surface. It was found that the presence of surfactants altered the direction of the shear layer in the vicinity of the free surface, with the shear layer being pulled to the higher surface tension side. In addition, the turbulence intensity in the plane of the free surface was dramatically reduced, also leading to damped surface deformations. These results show conclusively that the role surfactants play in turbulent free-surface shear flows needs to be considered.

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0801 Experimental Study on the Velocity Distribution in the Supersonic Jet Shear Layer and the Acoustic Waves

The Proceedings of the Fluids engineering conference ◽

10.1299/jsmefed.2015._0801-1_ ◽

2015 ◽

Vol 2015 (0) ◽

pp. _0801-1_-_0801-3_ ◽

Cited By ~ 1

Author(s):

Yuta Ozawa ◽

Taku Nonomura ◽

Kozo Fujii ◽

Makoto Yamamoto ◽

Yuya Mamori

Keyword(s):

Experimental Study ◽

Velocity Distribution ◽

Shear Layer ◽

Acoustic Waves ◽

Supersonic Jet

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Control of cavity tones using a spanwise cylinder

Canadian Journal of Physics ◽

10.1139/p08-086 ◽

2008 ◽

Vol 86 (12) ◽

pp. 1355-1365 ◽

Cited By ~ 5

Author(s):

L Keirsbulck ◽

M El Hassan ◽

M Lippert ◽

L Labraga

Keyword(s):

Experimental Study ◽

Shear Layer ◽

Layer Thickness ◽

Axial Velocity ◽

High Frequency ◽

Sound Pressure ◽

Leading Edge ◽

Deep Cavity ◽

Change In The Mean ◽

The Mean

A detailed experimental study of flow over a deep cavity was conducted towards understanding the attenuation of tones using a spanwise cylinder. Two “no-control” cavities were compared with a similar configuration using a cylinder on the leading edge of the cavities. Parametric changes of the spanwise cylinder such as the distance from the wall are studied. Maximum control across the range of studied velocities occurs for a particular position of the spanwise cylinder for the two configurations. Reductions in sound pressure levels (SPL) of up to 36 dB were obtained. Moreover, a shaped cylinder was also studied and shows that the attenuation of tones is not due to high-frequency pulsing as suggested in the literature, but to an increase of the cavity-shear-layer thickness due to the change in the mean axial velocity profiles.PACS Nos.: 47.27.Rc, 47.27.Sd

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