Fully Developed Turbulent Flow in an Annulus: Radius of Maximum Velocity

1971 ◽  
Vol 38 (4) ◽  
pp. 1090-1091 ◽  
Author(s):  
M. R. Doshi ◽  
W. N. Gill
Keyword(s):  
Turbulent Flow ◽  
Maximum Velocity ◽  
Fully Developed Turbulent Flow

Turbulent flow in smooth concentric annuli with small radius ratios

1974 ◽  
Vol 64 (2) ◽  
pp. 263-288 ◽  
Author(s):  
K. Rehme
Keyword(s):  
Reynolds Number ◽  
Shear Stress ◽  
Turbulent Flow ◽  
Strong Influence ◽  
Maximum Velocity ◽  
Small Radius ◽  
Stress Distributions ◽  
Number Range ◽  
Fully Developed Turbulent Flow ◽  
Flow Through

Fully developed turbulent flow through three concentric annuli was investigated experimentally for a Reynolds-number rangeRe= 2 × 104−2 × 105. Measurements were made of the pressure drop, the positions of zero shear stress and maximum velocity, and the velocity distribution in annuli of radius ratios α = 0.02, 0.04 and 0.1, respectively. The results for the key problem in the flow through annuli, the position of zero shear stress, showed that this position is not coincident with the position of maximum velocity. Furthermore, the investigation showed the strong influence of spacers on the velocity and shear-stress distributions. The numerous theoretical and experimental results in the literature which are based on the coincidence of the positions of zero shear stress and maximum velocity are not in agreement with reality.

An Analysis of Heat Transfer for Fully Developed Turbulent Flow in Concentric Annuli

1968 ◽  
Vol 90 (1) ◽  
pp. 43-50 ◽  
Author(s):  
N. W. Wilson ◽  
J. O. Medwell
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Turbulent Flow ◽  
Velocity Distribution ◽  
Maximum Velocity ◽  
Dimensionless Form ◽  
Temperature Distributions ◽  
Wide Range ◽  
Fully Developed Turbulent Flow ◽  
Heat And Momentum Transfer

The heat and momentum transfer analogy is employed to analyze the heat transfer phenomena for turbulent flow in concentric annuli. A modification of the velocity distribution due to Van Driest is assumed and equations in dimensionless form are developed to predict: (a) the position of maximum velocity in the annulus; (b) the friction factor-Reynolds number relationship, and (c) temperature distributions and heat transfer relations over a wide range of Reynolds number and Prandtl modulus.

Effect of Wetting on Friction Factors for Turbulent Flow of Mercury in Annuli

1976 ◽  
Vol 98 (1) ◽  
pp. 113-116 ◽  
Author(s):  
O. E. Dwyer ◽  
P. J. Hlavac ◽  
B. G. Nimmo
Keyword(s):  
Reynolds Number ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Maximum Velocity ◽  
Outer Wall ◽  
Limited Range ◽  
Friction Factors ◽  
Fully Developed Turbulent Flow

Friction factors were determined for fully developed turbulent flow of mercury in smooth concentric annuli under conditions where either both walls were unwetted, or both were wetted, or the inner wall was wetted and the outer one unwetted. Three radius ratios (r2/r1) were used, i.e., 2.09, 2.78, and 4.00. Unwetted walls gave the lowest friction factors, which were practically independent of the r2/r1 ratio over the limited range tested. The factors were 10 ± 1 percent higher than the commonly accepted values for smooth pipes (at the same Reynolds number). The highest friction factors were obtained with the inner wall wetted and the outer wall unwetted, and the greater the r2/r1 ratio the greater was the effect. For example, at r2/r1 = 4.00, the friction factors were 9.9% greater than for the situation when both walls were unwetted. The wetting conditions affected the location of the radius of maximum velocity (rm); and it was found that the nearer rm approached r2, the higher was the friction factor.

Incompressible Turbulent Flow in a Permeable-Walled Duct

1972 ◽  
Vol 94 (2) ◽  
pp. 314-319 ◽  
Author(s):  
E. M. Sparrow ◽  
V. K. Jonsson ◽  
G. S. Beavers ◽  
R. G. Owen
Keyword(s):  
Turbulent Flow ◽  
Turbulent Transport ◽  
Maximum Velocity ◽  
Porous Wall ◽  
Velocity Slip ◽  
Transport Processes ◽  
Porous Surface ◽  
Damping Factor ◽  
Wide Range ◽  
Fully Developed Turbulent Flow

An analysis is made of fully developed turbulent flow in a parallel-plate channel having one porous bounding wall. A velocity slip model is employed to characterize the boundary condition at the porous surface. The turbulent transport processes in the channel are represented via the Prandtl mixing length concept in conjunction with a modified form of the Van Driest damping factor. Numerical results are obtained for Reynolds numbers ranging from 5000 to 200,000 and for a wide range of values of a dimensionless slip grouping. The results show that velocity slip at the porous surface brings about a reduction in the friction factor, the extent of the reduction being accentuated with increasing Reynolds number. The velocity slip also causes a skewing of the velocity profiles, such that the location of the maximum velocity is shifted toward the porous wall.

An Experimental Investigation of Turbulent Flow in Concentric Annulus Using Particle Image Velocimetry Technique

2012 ◽  
Author(s):  
Fabio Ernesto Rodriguez Corredor ◽  
Majid Bizhani ◽  
Mohammad Ashrafuzzaman ◽  
Ergun Kuru
Keyword(s):  
Shear Stress ◽  
Particle Image Velocimetry ◽  
Turbulent Flow ◽  
Particle Image ◽  
Maximum Velocity ◽  
Wall Region ◽  
Number Range ◽  
Concentric Annulus ◽  
Image Velocimetry ◽  
Fully Developed Turbulent Flow

Fully developed turbulent flow in a concentric annulus is encountered in many engineering problems including food, chemical as well as oil industry applications. Because of nonlinear radial variation of total shear stress with the distance from the pipe wall, the analysis for the flow in annulus is more complex than in a round tube or parallel plate channel. In this study, fully developed turbulent flow of water through a horizontal flow loop with concentric annular geometry (inner to outer pipe radius ratio = 0.4) was investigated. Reynolds number range varied from 17,700 to 66,900. Velocity near the wall region was measured using high resolution particle image velocimetry (PIV) system. Axial mean velocity profile was found to be following the universal wall law (i.e., u+ = y+) close to the wall (for y+ < 10) and log law away from the wall (y+>10). For all the cases investigated, radial positions of the maximum velocity and zero shear stress were very close to each other (± 0.5 mm). The difference between the both locations were found to be varying from 1.3 to 3.3% ( 2% on the average).

scholarly journals Fully developed turbulent flow in a square duct with a rough wall.

1987 ◽  
Vol 53 (492) ◽  
pp. 2370-2376 ◽  
Author(s):  
Hideomi FUJITA ◽  
Hajime YOKOSAWA ◽  
Masafumi HIROTA ◽  
Satoru NISHIGAKI
Keyword(s):  
Turbulent Flow ◽  
Rough Wall ◽  
Square Duct ◽  
Fully Developed Turbulent Flow
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