Analysis of Experimental Data on Boundary Layer Pressure Fluctuations in Turbulent Pipe Flow

1990 ◽  
pp. 77-84
Author(s):  
Harrison T. Loeser
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Pipe Flow ◽  
Pressure Fluctuations ◽  
Turbulent Pipe Flow

Wall-pressure fluctuations in turbulent pipe flow

1987 ◽  
Vol 30 (10) ◽  
pp. 3019 ◽  
Author(s):  
Gerald C. Lauchle ◽  
Mark A. Daniels
Keyword(s):  
Pipe Flow ◽  
Pressure Fluctuations ◽  
Wall Pressure ◽  
Turbulent Pipe Flow ◽  
Wall Pressure Fluctuations

Fully developed periodic turbulent pipe flow. Part 1. Main experimental results and comparison with predictions

1983 ◽  
Vol 137 ◽  
pp. 31-58 ◽  
Author(s):  
S. W. Tu ◽  
B. R. Ramaprian
Keyword(s):  
Experimental Data ◽  
Pipe Flow ◽  
Shear Flows ◽  
Volumetric Flow Rate ◽  
Intermediate Frequency ◽  
Turbulent Pipe Flow ◽  
Experimental Results ◽  
Turbulent Shear ◽  
Relevant Parameter ◽  
Flow Modulation

The present paper is the first part of a two-part report on a detailed investigation of periodic turbulent pipe flow. In this investigation, experimental data on instantaneous velocity and wall shear stress were obtained at a mean Reynolds number of 50000 in a fully developed turbulent pipe flow in which the volumetric flow rate was varied sinusoidally with time around the mean. Two oscillation frequencies at significant levels of flow modulation were studied in detail. The higher of these frequencies was of the order of the turbulent bursting frequency in the flow, and the other can be regarded as an intermediate frequency at which the flow still departed significantly from quasi-steady behaviour. While a few similar experiments have been reported in the recent literature, the present study stands out from the others in respect of the flow regimes investigated, the magnitude of flow modulation, the detailed nature of the measurements and most importantly the identification of a relevant parameter to characterize unsteady shear flows. The present paper contains the main experimental results and comparisons of these results with the results of a numerical calculation procedure which employs a well-known quasi-steady turbulence closure model. The experimental data are used to study the manner in which the time-mean, the ensemble-averaged and the random flow properties are influenced by flow oscillation at moderate to high frequencies. In addition, the data are also used to bring out the capability and limitations of quasi-steady turbulence modelling in the prediction of unsteady shear flows. A further and more detailed analysis of the experimental data, results of some additional experiments and a discussion on the characterization of turbulent shear flows are provided in Part 2 (Ramaprian & Tu 1983).

scholarly journals Turbulent pipe flow: Statistics,Re-dependence, structures and similarities with channel and boundary layer flows

2014 ◽  
Vol 506 ◽  
pp. 012010 ◽  
Author(s):  
George K El Khoury ◽  
Philipp Schlatter ◽  
Geert Brethouwer ◽  
Arne V Johansson
Keyword(s):  
Boundary Layer ◽  
Pipe Flow ◽  
Turbulent Pipe Flow ◽  
Boundary Layer Flows ◽  
Dependence Structures

Predicting Drag Reduction in Turbulent Pipe Flow With Relaxation Time of Polymer Additives

2018 ◽  
Author(s):  
Xin Zhang ◽  
Xili Duan ◽  
Yuri Muzychka ◽  
Zongming Wang
Keyword(s):  
Experimental Data ◽  
Relaxation Time ◽  
Drag Reduction ◽  
Pipe Flow ◽  
Polymer Concentration ◽  
Weissenberg Number ◽  
Turbulent Pipe Flow ◽  
Dimensionless Number ◽  
Polymer Additives ◽  
Dilute Solution

This paper presents an experimental study on drag reduction induced by PEO (Polyethylene oxide) in a fully turbulent pipe flow. The objective of this work is to develop a correlation to predict drag reduction using the relaxation time of the polymer additives under dilute solution conditions, i.e., the polymer concentration is less than the overlap concertation. This paper discusses the meaning of relaxation time of polymers, and why the Weissenberg number, a dimensionless number that is related to the relaxation time and shear rate, is independent on the concentration in the dilute solution. Experimental data of drag reduction in a pipe flow are obtained from measurements using a flow loop. A correlation to predict drag reduction with the Weissenberg number and polymer concentration is established and a good agreement is shown between the predicted values and experimental data. The new correlation using the Weissenberg number and polymer concentration is shown to cost less to develop than one using the Reynolds number, in which larger pipes or higher flow rates are required.

The Preston tube as a means of measuring skin friction

1962 ◽  
Vol 14 (1) ◽  
pp. 1-17 ◽  
Author(s):  
M. R. Head ◽  
I. Rechenberg
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Skin Friction ◽  
Pipe Flow ◽  
Large Diameter ◽  
Turbulent Pipe Flow ◽  
Pitot Tube ◽  
Diameter Pipe ◽  
Flow Similarity ◽  
Considerable Doubt

Preston's method of measuring skin friction, which makes use of a Pitot tube resting on the surface, depends upon the assumption of a region of flow similarity, adjacent to the wall, common to fully developed turbulent pipe flow and the turbulent boundary layer. Experiments performed elsewhere have cast considerable doubt on the validity of this assumption, and the present investigation was undertaken to establish whether or not it is justified.Experiments were carried out in a short length of large-diameter pipe which could either form part of a very much longer pipe, giving fully developed turbulent pipe flow, or could be preceded by a conventional contraction and screens, giving a developing turbulent boundary layer.Final results showed that for a given skin friction the Pitot tube reading was the same for both boundary layer and pipe flows, thus vindicating Preston's method and confirming the existence of a universal region of wall similarity. Initial experimental difficulties were found to be due to unexpectedly large circumferential variations in skin friction in the growing boundary layer.

Further Experiments With Suction at a Sudden Enlargement in a Pipe

1970 ◽  
Vol 92 (3) ◽  
pp. 437-447 ◽  
Author(s):  
Gunnar Heskestad
Keyword(s):  
Boundary Layer ◽  
Pipe Flow ◽  
Expansion Ratio ◽  
Turbulent Pipe Flow ◽  
Thin Boundary Layer ◽  
Inlet Flow ◽  
Upper Limit ◽  
Sudden Enlargement ◽  
Flow Through ◽  
And Performance

Previously reported experiments on incompressible flow through a step expansion in a pipe, as influenced by suction at the smaller diameter of the step, have been extended to examine effects of inlet flow on suction requirements and performance of the device as a (short) diffuser. Here the performance for a fully developed turbulent pipe flow is considered and compared to previous results for an inlet flow with thin boundary layer. Whenever overall diffuser length is restricted to values less than some upper limit for a given expansion ratio, then for either inlet flow condition, the present device is shown to produce higher pressure recoveries (adjusted for suction power) than conical diffusers.

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