Skin Friction and the Inner Flow in Pressure Gradient Turbulent Boundary Layers

Analysis of the factors contributing to the skin friction coefficient in adverse pressure gradient turbulent boundary layers and their variation with the pressure gradient

International Journal of Heat and Fluid Flow ◽

10.1016/j.ijheatfluidflow.2019.108531 ◽

2020 ◽

Vol 82 ◽

pp. 108531

Author(s):

Shevarjun Senthil ◽

Vassili Kitsios ◽

Atsushi Sekimoto ◽

Callum Atkinson ◽

Julio Soria

Keyword(s):

Friction Coefficient ◽

Pressure Gradient ◽

Skin Friction ◽

Boundary Layers ◽

Adverse Pressure Gradient ◽

Skin Friction Coefficient ◽

Turbulent Boundary Layers

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Approach to an asymptotic state for zero pressure gradient turbulent boundary layers

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2006.1948 ◽

2007 ◽

Vol 365 (1852) ◽

pp. 755-770 ◽

Cited By ~ 149

Author(s):

Hassan M Nagib ◽

Kapil A Chauhan ◽

Peter A Monkewitz

Keyword(s):

Experimental Data ◽

Pressure Gradient ◽

Skin Friction ◽

Boundary Layers ◽

Classical Theory ◽

Reynolds Numbers ◽

Turbulent Boundary Layers ◽

Careful Examination ◽

Mean Velocity ◽

Logarithmic Law

Flat plate turbulent boundary layers under zero pressure gradient at high Reynolds numbers are studied to reveal appropriate scale relations and asymptotic behaviour. Careful examination of the skin-friction coefficient results confirms the necessity for direct and independent measurement of wall shear stress. We find that many of the previously proposed empirical relations accurately describe the local C f behaviour when modified and underpinned by the same experimental data. The variation of the integral parameter, H , shows consistent agreement between the experimental data and the relation from classical theory. In accordance with the classical theory, the ratio of Δ and δ asymptotes to a constant. Then, the usefulness of the ratio of appropriately defined mean and turbulent time-scales to define and diagnose equilibrium flow is established. Next, the description of mean velocity profiles is revisited, and the validity of the logarithmic law is re-established using both the mean velocity profile and its diagnostic function. The wake parameter, Π , is shown to reach an asymptotic value at the highest available experimental Reynolds numbers if correct values of logarithmic-law constants and an appropriate skin-friction estimate are used. The paper closes with a discussion of the Reynolds number trends of the outer velocity defect which are important to establish a consistent similarity theory and appropriate scaling.

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Determination of skin friction in strong pressure-gradient equilibrium and near-equilibrium turbulent boundary layers

Experiments in Fluids ◽

10.1007/s00348-009-0698-2 ◽

2009 ◽

Vol 47 (6) ◽

pp. 1045-1058 ◽

Cited By ~ 21

Author(s):

Shivsai Ajit Dixit ◽

O. N. Ramesh

Keyword(s):

Pressure Gradient ◽

Skin Friction ◽

Boundary Layers ◽

Turbulent Boundary Layers

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An Improved Version of the Cebeci-Smith Eddy-Viscosity Model

Aeronautical Quarterly ◽

10.1017/s0001925900008441 ◽

1978 ◽

Vol 29 (3) ◽

pp. 207-225 ◽

Cited By ~ 9

Author(s):

M.J. Nituch ◽

S. Sjolander ◽

M.R. Head

Keyword(s):

Pressure Gradient ◽

Skin Friction ◽

Boundary Layers ◽

Eddy Viscosity ◽

Adverse Pressure Gradient ◽

Turbulent Boundary Layers ◽

Viscosity Model ◽

Eddy Viscosity Model ◽

Smith Method

SummaryAlthough the Cebeci-Smith method of calculating turbulent boundary layers is widely used and generally gives acceptably accurate results, highly inaccurate skin-friction values are obtained for relaxing flows and equilibrium layers in strong adverse pressure gradient. In the present paper, these anomalies are removed by suitable modifications to the basic eddy-viscosity model.

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