EXPERIMENTAL DETERMINATION OF SKIN FRICTION IN TURBULENT BOUNDARY LAYERS WITH FAVORABLE AND ADVERSE PRESSURE GRADIENTS

This paper reports the results of an extensive experimental investigation into the mean flow properties of turbulent boundary layers with momentum-thickness Reynolds numbers less than 3000. Zero pressure gradient and favorable pressure gradients were studied. The velocity profiles displayed a logarithmic region even at very low Reynolds numbers (as low as Rθ = 261). The results were independent of the leading-edge shape, and the pin-type turbulent stimulators performed well. It was found that the shape and Clauser parameters were a little higher than the correlation proposed by Coles [10], and the skin friction coefficient was a little lower. The skin friction coefficient behavior could be fitted well by a simple power-law relationship in both zero and favorable pressure gradients.

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The determination of the local skin friction and the thickness of turbulent boundary layers from the velocity similarity laws1

International Shipbuilding Progress ◽

10.3233/isp-1960-76903 ◽

1960 ◽

Vol 7 (69) ◽

pp. 213-220 ◽

Cited By ~ 1

Author(s):

Paul S. Granville

Keyword(s):

Skin Friction ◽

Boundary Layers ◽

Turbulent Boundary Layers ◽

Local Skin ◽

Local Skin Friction

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Prediction of Transpired Turbulent Boundary Layers With Arbitrary Pressure Gradients

Journal of Fluids Engineering ◽

10.1115/1.2819276 ◽

1997 ◽

Vol 119 (3) ◽

pp. 526-532 ◽

Cited By ~ 2

Author(s):

Miodrag Oljaca ◽

James Sucec

Keyword(s):

Experimental Data ◽

Skin Friction ◽

Boundary Layers ◽

Integral Method ◽

Skin Friction Coefficient ◽

Turbulent Boundary Layers ◽

Pressure Gradients ◽

Wide Range ◽

Better Than ◽

Good Agreement

An integral method, using Coles combined inner and outer law as the velocity profile, is developed for calculation of turbulent boundary layers with blowing or suction and pressure gradients. The resulting ordinary differential equations are solved numerically for the distribution of skin friction coefficient and integral thickness along the surface. Comparisons of predicted skin friction coefficients with experimental data are made for a wide range of blowing and suction rates and for various pressure gradients, including adverse, zero and a strong favorable gradient. In addition to good agreement with experimental data for constant blowing fractions F, the method is also successfully tested on cases where the blowing fraction is variable with position. Predictions, in general, exhibit satisfactory agreement with the data. The integral method predictions are comparable to, or better than, a number of finite difference procedures in a limited number of cases where comparisons were made.

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The measurement of skin friction in turbulent boundary layers with adverse pressure gradients

Journal of Fluid Mechanics ◽

10.1017/s0022112069001418 ◽

1969 ◽

Vol 35 (4) ◽

pp. 737-757 ◽

Cited By ~ 52

Author(s):

K. C. Brown ◽

P. N. Joubert

Keyword(s):

Shear Stress ◽

Skin Friction ◽

Boundary Layers ◽

Three Dimensional ◽

Turbulent Boundary Layers ◽

Pressure Gradients ◽

Two Dimensional ◽

Direct Measurements ◽

Floating Element ◽

Dimensional Boundary

This paper describes a floating-element skin friction meter which has been designed for use in adverse pressure gradients. The effects of secondary forces on the element, which arise from the pressure gradient, are examined in some detail. The limitations of various methods of measuring wall shear stress are discussed and the results from the floating element device are compared with measurements taken in a two-dimensional boundary layer using Preston tubes and velocity profiles. As it is planned to use the instrument later for direct measurements of the shear stress in three-dimensional boundary layers, the relevance of the instrument to this situation is also discussed.

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