scholarly journals Discussion: “Friction Factors for Turbulent Flow in Curved Pipes” (Itō, H., 1959, ASME J. Basic Eng., 81, pp. 123–132)

1959 ◽  
Vol 81 (2) ◽  
pp. 132-133
Author(s):  
L. MacG. Trefethen
Keyword(s):  
Turbulent Flow ◽  
Curved Pipes ◽  
Friction Factors

Analogy between turbulent flows in curved pipes and orthogonally rotating pipes

1996 ◽  
Vol 307 ◽  
pp. 1-10 ◽  
Author(s):  
Hiroshi Ishigaki
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Turbulent Flow ◽  
Turbulent Flows ◽  
Laminar Flows ◽  
Computational Results ◽  
Transfer Rates ◽  
Fundamental Parameters ◽  
Curved Pipes ◽  
Friction Factors

A quantitative analogy between fully developed turbulent flows in curved pipes and orthogonally rotating pipes will be described through similarity arguments, the use of experimental data and computational results. A pair of similarity parameters will be derived for each turbulent flow, so that they have the same dynamical meaning as those of laminar flows. When the second parameter for each flow is large enough, it will be shown that friction factors, as well as heat transfer rates, of the two flows coincide for equal values of the fundamental parameters. Computed contours of velocity and temperature will also reveal strong similarities between the two flows.

Friction Factors for Turbulent Flow in Curved Pipes

1959 ◽  
Vol 81 (2) ◽  
pp. 123-132 ◽  
Author(s):  
H. Itō
Keyword(s):  
Turbulent Flow ◽  
Reliable Data ◽  
Empirical Formulas ◽  
Pressure Losses ◽  
Satisfactory Accuracy ◽  
Curved Pipes ◽  
Friction Factors ◽  
The Law ◽  
Theoretical Considerations

The object of this paper is to furnish the engineer with reliable data on the friction factors to be used in computing the pressure losses for turbulent flow in smooth curved pipes. The empirical formulas proposed, backed by theoretical considerations, appear to define the influence of curvature upon the law of resistance with satisfactory accuracy.

Numerical and Experimental Analysis of Turbulent Flow in Corrugated Pipes

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Henrique Stel ◽  
Rigoberto E. M. Morales ◽  
Admilson T. Franco ◽  
Silvio L. M. Junqueira ◽  
Raul H. Erthal ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Turbulence Models ◽  
Reynolds Numbers ◽  
Velocity Magnitude ◽  
Geometric Configurations ◽  
Corrugated Surfaces ◽  
Friction Factors

This article describes a numerical and experimental investigation of turbulent flow in pipes with periodic “d-type” corrugations. Four geometric configurations of d-type corrugated surfaces with different groove heights and lengths are evaluated, and calculations for Reynolds numbers ranging from 5000 to 100,000 are performed. The numerical analysis is carried out using computational fluid dynamics, and two turbulence models are considered: the two-equation, low-Reynolds-number Chen–Kim k-ε turbulence model, for which several flow properties such as friction factor, Reynolds stress, and turbulence kinetic energy are computed, and the algebraic LVEL model, used only to compute the friction factors and a velocity magnitude profile for comparison. An experimental loop is designed to perform pressure-drop measurements of turbulent water flow in corrugated pipes for the different geometric configurations. Pressure-drop values are correlated with the friction factor to validate the numerical results. These show that, in general, the magnitudes of all the flow quantities analyzed increase near the corrugated wall and that this increase tends to be more significant for higher Reynolds numbers as well as for larger grooves. According to previous studies, these results may be related to enhanced momentum transfer between the groove and core flow as the Reynolds number and groove length increase. Numerical friction factors for both the Chen–Kim k-ε and LVEL turbulence models show good agreement with the experimental measurements.

Thermally Developing Single-Phase Flows in Microtubes

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
Mehmed Rafet Özdemir ◽  
Ali Koşar
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Single Phase ◽  
High Mass ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Mass Fluxes ◽  
Friction Factors ◽  
Developing Flow ◽  
Theoretical Predictions

The pressure drop and heat transfer due to the flow of de-ionized water at high mass fluxes in microtubes of ∼ 254 μm and ∼ 685 μm inner diameters is investigated in the laminar, transition and the turbulent flow regimes. The flow is hydrodynamically fully developed and thermally developing. The experimental friction factors and heat transfer coefficients are respectively predicted to within ±20% and ±30% by existing open literature correlations. Higher single phase heat transfer coefficients were obtained with increasing mass fluxes, which is motivating to operate at high mass fluxes and under thermally developing flow conditions. The transition to turbulent flow and friction factors for both laminar and turbulent conditions were found to be in agreement with existing theory. A reasonable agreement was present between experimental results and theoretical predictions recommended for convective heat transfer in thermally developing flows.

Experiments on turbulent-flow phenomena in eccentric annular ducts

1966 ◽  
Vol 25 (1) ◽  
pp. 65-86 ◽  
Author(s):  
V. K. Jonsson ◽  
E. M. Sparrow
Keyword(s):  
Turbulent Flow ◽  
Complete Agreement ◽  
Eccentric Annulus ◽  
Law Of The Wall ◽  
Contour Maps ◽  
Friction Factors ◽  
Flow Phenomena ◽  
Local Shear ◽  
Experimental Findings ◽  
Universal Law

The investigation to be described here is a wide-ranging experimental study aimed at determining both the details of the flow field and the pressure drop and friction factor characteristics for turbulent flow in eccentric annular ducts. The experiments were performed utilizing three annular ducts of different diameter ratios; in each case the eccentricity was varied from zero (concentric annulus) to unity (walls in contact). To provide the broadest possible perspective, the measurements of the velocity field are presented in three different ways. First, contour maps showing lines of constant velocity are constructed. From these are deduced circumferential distributions of the local shear stress on the bounding walls. Velocity profiles along lines normal to the walls are represented in terms of both law-of-the-wall variables and defect-law variables. Neither of these representations affords complete agreement with the universal circular-tube distributions. In general, the defect law provides a somewhat closer correlation of the results for the eccentric annulus with those for the tube. The experimental findings do not substantiate a prior analytical model which assumes that the universal law of the wall applies on all lines normal to the bounding walls of the annulus. Friction factors, based on static pressure measurements, are shown to decrease with increasing eccentricity. The measured friction factors are in fair agreement with those of analysis. Hydrodynamic development lengths, deduced from entrance-region pressure data, are found to increase with increasing eccentricity. Circumferential pressure variations also increase with eccentricity.

Analogy between laminar flows in curved pipes and orthogonally rotating pipes

1994 ◽  
Vol 268 ◽  
pp. 133-145 ◽  
Author(s):  
Hiroshi Ishigaki
Keyword(s):  
Laminar Flows ◽  
Computational Studies ◽  
Flow Properties ◽  
Straight Pipe ◽  
Pipe Axis ◽  
Transfer Rates ◽  
Curved Pipe ◽  
Curved Pipes ◽  
Data Similarity ◽  
Friction Factors

The secondary flow of a viscous fluid, caused by the Coriolis force, through a straight pipe rotating about an axis perpendicular to the pipe axis is analogous to that of a fluid, caused by the centrifugal force, through a stationary curved pipe. The quantitative analogy between these two fully developed laminar flows will be demonstrated through similarity arguments, computational studies and the use of experimental data. Similarity considerations result in two analogous governing parameters for each flow, which include a new one for the rotating flow. When one of these analogous pairs of parameters of the two flows is large, it will be demonstrated that there are strong similarities between the two flows regarding friction factors, heat transfer rates, flow patterns and flow properties for the same values of the other pair of parameters.

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