Average Velocity Distribution of Turbulent Pipe Flow with Emphasis on the Viscous Sublayer

1969 ◽  
Vol 12 (7) ◽  
pp. 1364 ◽  
Author(s):  
E. Rune Lindgren
Keyword(s):  
Velocity Distribution ◽  
Pipe Flow ◽  
Average Velocity ◽  
Viscous Sublayer ◽  
Turbulent Pipe Flow

Velocity measurements made with a laser dopplermeter on the turbulent pipe flow of a dilute polymer solution

1972 ◽  
Vol 51 (4) ◽  
pp. 673-685 ◽  
Author(s):  
M. J. Rudd
Keyword(s):  
Polymer Solution ◽  
Velocity Component ◽  
Pipe Flow ◽  
Viscous Sublayer ◽  
Turbulent Pipe Flow ◽  
Velocity Measurements ◽  
Velocity Fluctuations ◽  
Conventional Models ◽  
Drag Reducing Polymer ◽  
Spanwise Velocity

This paper presents some new measurements which have been made on a drag-reducing polymer solution in pipe flow. A novel type of laser dopplermeter, which has been developed by the author, is briefly described and the measurements which have been obtained are given. These results and their implications are then discussed in terms of conventional models for turbulent flow in a pipe. These suggest that the polymer has very little effect upon the turbulent core of the flow, but thickens and stabilizes the viscous sublayer. The turbulent intensity inside the sublayer is unchanged but, owing to its thickening, the velocity fluctuations just outside are greater. There is not a general suppression of turbulence within the sublayer although well inside the sublayer the spanwise velocity component is found to be reduced.

Velocity distribution in the core of turbulent pipe flow

1969 ◽  
Vol 24 (4) ◽  
pp. 787-791 ◽  
Author(s):  
B.J. Brinkworth ◽  
P.C. Smith
Keyword(s):  
Velocity Distribution ◽  
Pipe Flow ◽  
Turbulent Pipe Flow ◽  
The Core

A tracer dispersion study of the drag-reduction effect in a turbulent pipe flow

1971 ◽  
Vol 47 (2) ◽  
pp. 209-230 ◽  
Author(s):  
A. W. Bryson ◽  
Vr. Arunachalam ◽  
G. D. Fulford
Keyword(s):  
Molecular Weight ◽  
Drag Reduction ◽  
Pipe Flow ◽  
Viscous Sublayer ◽  
Turbulent Pipe Flow ◽  
Reduction Mechanism ◽  
Response Curves ◽  
Pipe Flows ◽  
Tracer Dispersion ◽  
Reduction Effect

Remarkable differences in dispersion of a tracer material injected into turbulent pipe flows of water and water containing as little as 2·5 parts per million by weight of a soluble high-molecular-weight drag-reducing polyoxyethylene additive have been measured. Analysis of the tracer response curves in terms of a simple one-parameter model shows that the observed results are compatible with a drag-reduction mechanism based on thickening of the viscous sublayer adjoining the wall. Other experiments, reported briefly, suggest that polymer adsorption on to the wall is responsible for this thickening.

Studies of the wall shear stress in a turbulent pulsating pipe flow

1986 ◽  
Vol 170 ◽  
pp. 545-564 ◽  
Author(s):  
Zhuo-Xiong Mao ◽  
Thomas J. Hanratty
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Pipe Flow ◽  
Relaxation Effect ◽  
Viscous Sublayer ◽  
Turbulent Pipe Flow ◽  
Sharp Change ◽  
Dimensionless Frequency ◽  
Median Frequency ◽  
Wall Shear

Measurements are presented of the time variation of the wall shear stress caused by the imposition of a sinusoidal oscillation on a turbulent pipe flow. The amplitude of the oscillation is small enough that a linear response is obtained and the dimensionless frequency, ω+ = ων/u*2, is large compared with that studied by most previous investigators. The most striking feature of the results is a relaxation effect, similar to that observed for flow over a wavy surface, whereby the phase angle characterizing the temporal variation of the wall shear stress undergoes a sharp change over a rather narrow range of ω+. At ω+ larger than the median frequency of the turbulence there appears to be an interaction between the imposed flow oscillation and the turbulence fluctuations in the viscous sublayer, which is not described by present theories of turbulence.

Velocity distribution of turbulent pipe flow

1990 ◽  
Vol 24 (11) ◽  
pp. 715-718
Author(s):  
S. A. Pankratov
Keyword(s):  
Velocity Distribution ◽  
Pipe Flow ◽  
Turbulent Pipe Flow
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