Mean-Velocity Profile of Turbulent Boundary Layers Approaching Separation

AIAA Journal ◽  
2006 ◽  
Vol 44 (11) ◽  
pp. 2465-2474 ◽  
Author(s):  
Thomas Indinger ◽  
Matthias H. Buschmann ◽  
Mohamed Gad-el-Hak
Keyword(s):  
Velocity Profile ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Mean Velocity

On the invariant mean velocity profile for compressible turbulent boundary layers

2017 ◽  
Vol 18 (2) ◽  
pp. 186-202 ◽  
Author(s):  
Bin Wu ◽  
Weitao Bi ◽  
Fazle Hussain ◽  
Zhen-Su She
Keyword(s):  
Velocity Profile ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Invariant Mean ◽  
Mean Velocity

Mach-Number-Invariant Mean-Velocity Profile of Compressible Turbulent Boundary Layers

2012 ◽  
Vol 109 (5) ◽  
Author(s):  
You-Sheng Zhang ◽  
Wei-Tao Bi ◽  
Fazle Hussain ◽  
Xin-Liang Li ◽  
Zhen-Su She
Keyword(s):  
Mach Number ◽  
Velocity Profile ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Invariant Mean ◽  
Mean Velocity

The mean velocity profile of turbulent boundary layers with system rotation

2000 ◽  
Vol 408 ◽  
pp. 323-345 ◽  
Author(s):  
T. B. NICKELS ◽  
P. N. JOUBERT
Keyword(s):  
Velocity Profile ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Secondary Flows ◽  
Pressure Gradients ◽  
Mean Velocity ◽  
System Rotation ◽  
Linear Correction ◽  
The Mean ◽  
The University

This paper examines changes in the mean velocity profiles of turbulent boundary layers subjected to system rotation. Analysis of the data from several studies conducted in the large rotating wind tunnel at the University of Melbourne shows the existence of a universal linear correction to the velocity profile in the logarithmic region. The appropriate parameters relevant to rotation are derived and correlations are found between the parameters. Flows with adverse pressure gradients, zero pressure gradients and secondary flows are examined and all appear to exhibit the universal linear correction, suggesting that it is robust.

Turbulent Flow Near a Rough Wall

1992 ◽  
Vol 114 (4) ◽  
pp. 537-542 ◽  
Author(s):  
Yang-Moon Koh
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Velocity Profile ◽  
Boundary Layers ◽  
Simple Formula ◽  
Turbulent Boundary Layers ◽  
Mean Velocity ◽  
Friction Factors ◽  
Special Cases ◽  
The Mean

By introducing the equivalent roughness which is defined as the distance from the wall to where the velocity gets a certain value (u/uτ ≈ 8.5) and which can be represented by a simple function of the roughness, a simple formula to represent the mean-velocity distribution across the inner layer of a turbulent boundary layer is suggested. The suggested equation is general enough to be applicable to turbulent boundary layers over surfaces of any roughnesses covering from very smooth to completely rough surfaces. The suggested velocity profile is then used to get expressions for pipe-friction factors and skin friction coefficients. These equations are consistent with existing experimental observations and embrace well-known equations (e.g., Prandtl’s friction law for smooth pipes and Colebrook’s formula etc.) as special cases.

Measurements in adverse-pressure-gradient turbulent boundary layers with a step change in surface roughness

1975 ◽  
Vol 70 (3) ◽  
pp. 573-593 ◽  
Author(s):  
W. H. Schofield
Keyword(s):  
Surface Roughness ◽  
Pressure Gradient ◽  
Boundary Layers ◽  
Leading Edge ◽  
Adverse Pressure Gradient ◽  
Turbulent Boundary Layers ◽  
Step Change ◽  
Internal Layer ◽  
Mean Velocity ◽  
Law Of The Wall

The response of turbulent boundary layers to sudden changes in surface roughness under adverse-pressure-gradient conditions has been studied experimentally. The roughness used was in the ‘d’ type array of Perry, Schofield & Joubert (1969). Two cases of a rough-to-smooth change in surface roughness were considered in the same arbitrary adverse pressure gradient. The two cases differed in the distance of the surface discontinuity from the leading edge and gave two sets of flow conditions for the establishment and growth of the internal layer which develops downstream from a change in surface roughness. These conditions were in turn different from those in the zero-pressure-gradient experiments of Antonia & Luxton. The results suggest that the growth of the new internal layer depends solely on the new conditions at the wall and scales with the local roughness length of that wall. Mean velocity profiles in the region after the step change in roughness were accurately described by Coles’ law of the wall-law of the wake combination, which contrasts with the zero-pressure-gradient results of Antonia & Luxton. The skin-friction coefficient after the step change in roughness did not overshoot the equilibrium distribution but made a slow adjustment downstream of the step. Comparisons of mean profiles indicate that similar defect profile shapes are produced in layers with arbitrary adverse pressure gradients at positions where the values of Clauser's equilibrium parameter β (= δ*τ−10dp/dx) are similar, provided that the pressure-gradient history and local values of the pressure gradient are also similar.

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