Closure to “Discussion of ‘Pressure Losses in Smooth Pipe Bends’” (1960, ASME J. Basic Eng., 82, pp. 140–142)

1960 ◽  
Vol 82 (1) ◽  
pp. 142-143
Author(s):  
H. Ito¯
Keyword(s):  
Pressure Losses ◽  
Smooth Pipe

The Flow and Pressure Losses in Smooth Pipe Bends of Constant Cross Section

1963 ◽  
Vol 67 (631) ◽  
pp. 437-447 ◽  
Author(s):  
A. J. Ward Smith
Keyword(s):  
Reynolds Number ◽  
Cross Section ◽  
Experimental Information ◽  
Bend Angle ◽  
Geometrical Parameters ◽  
Constant Cross Section ◽  
Cross Sectional ◽  
Pressure Losses ◽  
Smooth Pipe ◽  
Sectional Shape

SummaryIncompressible turbulent flow in smooth pipe bends of circular-arc curvature and constant cross section is discussed. The effects of bend angle, radius ratio, duct cross-sectional shape and Reynolds number are considered. Particular attention is paid to the influence of the tangents on the flow and losses in a bend. In addition consideration is given to the definition and measurement of the bend loss.A correlation of experimental pressure loss data is made. It is shown that large variations in experimental results, which cannot be ascribed to the effects of geometrical parameters or Reynolds number, are accounted for by the effects of the downstream tangent and position at which the pressure measurements were made. The inadequacy of existing experimental information is an obstacle to the presentation of comprehensive data on the effect of geometrical parameters on bend losses.

Friction Factor In Sine-Pipe Flow

1996 ◽  
Vol 118 (2) ◽  
pp. 341-345 ◽  
Author(s):  
C. O. Popiel ◽  
D. F. van der Merwe
Keyword(s):  
Reynolds Number ◽  
Friction Factor ◽  
Wave Length ◽  
Smooth Transition ◽  
Straight Tube ◽  
Dean Number ◽  
Turbulent Region ◽  
Pressure Losses ◽  
Smooth Pipe ◽  
Darcy Friction Factor

Measurements of pressure losses in a sine-waved hydraulically smooth pipe, having a centerline described by the formula y = h sin (2πx/λ), are presented. The effect of the dimensionless wave-length (λ/d) and amplitude (h/d) on the Darcy friction factor was investigated in the range of the Reynolds number from about 100 to 10 000, and in the ranges of wavelength from λ/d = 17.7 to 150 and amplitude from h/d = 1.5 to 32. The Dean number, based on the minimum radius of the sine-waved centerline curvature, below which the influence of the sine-pipe shape in comparison to the straight tube was not seen is De ≤ ~20. A smooth transition from laminar to turbulent region in the friction factor versus Reynolds number plot was observed. In turbulent region the effect of the sine-pipe shape can be neglected for λ/d ≥ 1.36*h/d + 36.2.

Pressure Losses in Smooth Pipe Bends

1960 ◽  
Vol 82 (1) ◽  
pp. 131-140 ◽  
Author(s):  
H. Ito¯
Keyword(s):  
Cross Section ◽  
Experimental Studies ◽  
Circular Cross Section ◽  
Empirical Formulas ◽  
Design Problems ◽  
Pressure Losses ◽  
Test Information ◽  
Present Test ◽  
Practical Design ◽  
Smooth Pipe

The results of extensive experimental studies to determine the pressure losses for turbulent flow in smooth pipe bends of circular cross section are presented in this paper. To make the data usable in practical design problems, the results are discussed in relation to those found by previous investigators, and empirical formulas for the bend-loss coefficient are given. The general correlation of the test data appears to be as good as our present test information will permit.

PRESSURE LOSSES AND HEAT TRANSFER FOR FLOW OF DRAG REDUCING SURFACTANT SOLUTIONS IN PIPES AND FITTINGS

Equipment ◽  
2006 ◽  
Author(s):  
J. Sestak ◽  
V. Mik ◽  
J. Myska ◽  
M. Dostal ◽  
L. Mihalka
Keyword(s):  
Heat Transfer ◽  
Pressure Losses ◽  
Surfactant Solutions

Modeling of pressure losses on friction in three-layer laminar flows

2003 ◽  
Vol 3 ◽  
pp. 208-219
Author(s):  
A.M. Ilyasov
Keyword(s):  
Pressure Loss ◽  
Gas Flow ◽  
Mutual Influence ◽  
Fluid Model ◽  
Immiscible Liquid ◽  
Laminar Flows ◽  
Pressure Losses ◽  
Flow Parameters ◽  
Interphase Boundaries ◽  
Closing Relations

In this paper we propose a model for determining the pressure loss due to friction in each phase in a three-layer laminar steady flow of immiscible liquid and gas flow in a flat channel. This model generalizes an analogous problem for a two-layer laminar flow, proposed earlier. The relations obtained in the final form for the pressure loss due to friction in liquids can be used as closing relations for the three-fluid model. These equations take into account the influence of interphase boundaries and are an alternative to the approach used in foreign literature. In this approach, the wall and interphase voltages are approximated by the formulas for a single-phase flow and do not take into account the mutual influence of liquids on the loss of pressure on friction in phases. The distribution of flow parameters in these two models is compared.

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