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Title:

EFFECT OF RIBLETS ON TURBULENCE IN THE WAKE OF AN AIRFOIL

Accession Number:

00701534

Record Type:

Monograph

Abstract:

Measurements were made in the near and intermediate wake regions of a NACA 0012 airfoil with three different riblet sizes at a freestream Reynolds number of 2.5 x 105. The riblets tested were a symmetric v-groove type of heights 0.0229, 0.076, and 0.152 mm, respectively. To ensure turbulent flow on the airfoil, a transition strip was applied at 10% of the chord. Wake velocity profiles and turbulence parameters were measured with a temperature compensated hot-film x-probe. Riblet effectiveness was indicated by marked decrease in turbulence levels in the wake. Integration of the wake mean velocity profiles indicated a net reduction in drag of up to 13.3%, which was possibly caused by the combined effect of decreased turbulent shear stress and lower momentum exchange near the surface due to a viscosity-dominated region in the riblet valleys.

Supplemental Notes:

AIAA J, v 29 n 11, Nov 1991, p 1769 [2 p, 7 ref, 5 tab, 1 fig]

Language:

English

Authors:

Caram, J M
Ahmed, A

Publication Date:

1991

Old TRIS Terms:

Subject Areas:

Marine Transportation; Vehicles and Equipment

Source Agency:

British Maritime Technology

Source Data:

91122940

Files:

TRIS

Last Modified:

Sep 8 1995 12:00AM