Experimental Investigation on Pressure Drop in Corrugated Pipes

2013 ◽  
Author(s):  
Hojin Ahn ◽  
Ibrahim Uslu
Keyword(s):  
Pressure Drop ◽  
Friction Factor ◽  
Cross Section ◽  
Circular Cross Section ◽  
Control Valve ◽  
Experimental Result ◽  
Helical Coil ◽  
Solar Panels ◽  
Steel Pipes ◽  
Friction Factors

The characteristics of pressure drop in corrugated pipes were experimentally studied in both straight and helically coiled configurations. The present study employed the stainless-steel pipes with the corrugation of circular cross section, which are widely used in boilers and pipe systems between solar panels and boilers. The diameters of corrugated pipes were 20.4, 25.4, 34.5 and 40.5 mm. The corrugated pipe, approximately 10 m in length, was configured either in the straight manner or in the helical coil with the helix diameter of 0.43 or 0.64 m. Water stored in a tank was fed into a corrugated pipe by a pump while the flow rate was controlled by a control valve. The friction factors of the pipes remain constant over the range of Reynolds number from 4,000 to 50,000, indicating that the flow in the pipe was fully turbulent. When the pipe was straightly configured, the friction factors were measured to be 0.070, 0.075, 0.12 and 0.22 for the diameter of 20.4, 25.4, 34.5 and 40.5 mm, respectively. Thus the present study showed that the friction factors increased with the increasing diameter of the pipe. This result is clearly contrary to a rare experimental result available in the literature. On the other hand, as expected, the friction factor for the helically coiled configuration was higher than that of the straight configuration with the same tube diameter, and the configuration of the smaller helix diameter yielded the larger friction factor. The reason for the increasing friction factor with the increasing pipe diameter remains to be explored further.

Flow in Rotating Straight Pipes of Circular Cross Section

1971 ◽  
Vol 93 (3) ◽  
pp. 383-394 ◽  
Author(s):  
H. Ito¯ ◽  
K. Nanbu
Keyword(s):  
Friction Factor ◽  
Cross Section ◽  
Circular Cross Section ◽  
Constant Angular Velocity ◽  
Smooth Wall ◽  
Good Qualitative Agreement ◽  
Fully Developed Flow ◽  
Number Range ◽  
Friction Factors ◽  
Laminar And Turbulent Flow

The friction factor for fully developed flow in smooth wall straight pipes of circular cross section rotating at a constant angular velocity about an axis perpendicular to its own has been measured in the Reynolds number range from 20 to 60,000. Empirical equations for friction factors for small values of RΩ/R were presented for both laminar and turbulent flow. In the case of laminar flow, an approximate analysis based on the assumption that the flow consists of a frictionless central core surrounded by a boundary layer was presented. The results were in good qualitative agreement with experimental results in regard to the friction factor, velocity distribution in the plane of symmetry and pressure distribution along the circumferential wall of the pipe.

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.

Frictional Pressure Drop in Micro-Channel

2004 ◽  
Author(s):  
Yasuo Koizumi ◽  
Hiroyasu Ohtake ◽  
Hiroki Takahashi ◽  
Yoshiaki Ohno
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Friction Factor ◽  
Frictional Pressure Drop ◽  
Turbulent Transition ◽  
Friction Factors ◽  
Turbulent Flow Regime ◽  
Form Pressure ◽  
Laminar And Turbulent Flow ◽  
Flow Through

The friction characteristics of water in a sub-millimeter scale channel were investigated experimentally. The friction factors and the critical Reynolds number were measured using water flow through circular tubes with diameters of 0.5, 0.25 and 0.17 mm. The experimental results show that the measured friction factor for water agreed well with the conventional Poiseuille (λ = 64/Re) and Blasius (λ = 0.316 Re−0.25) equations in laminar and turbulent flow regime; the laminar-turbulent transition Reynolds number was approximately 2300 for diameter 0.5 mm. For diameter 0.25 mm, the friction factor evaluated by the form pressure drop also agreed well with the Poiseuille equation. For diameter 0.17 mm, the measured total friction factor was close to the Poiseuille prediction.

Experimental Study and Numerical Analysis of Water Single-Phase Pressure Drop Across an Array of Circular Micro-Pin-Fins

2011 ◽  
Author(s):  
Jonathan R. Mita ◽  
Weilin Qu ◽  
Marcelo H. Kobayashi ◽  
Frank E. Pfefferkorn
Keyword(s):  
Numerical Analysis ◽  
Pressure Drop ◽  
Cross Section ◽  
Single Phase ◽  
Three Dimensional ◽  
Circular Cross Section ◽  
Experimental Results ◽  
Inlet Temperature ◽  
Pin Fins ◽  
Micro Pin Fins

This study investigates pressure drop associated with water liquid single-phase flow across an array of staggered micro-pin-fins having circular cross-section. The micro-pin-fins are micro-end milled out of oxygen free copper and have the following dimensions: 180 micron diameter and 683 micron height. The longitudinal pitch and transverse pitch are equal to 400 microns. Seven water inlet temperatures from 22 to 80 °C, and seventeen maximum mass velocities for each inlet temperature, ranging from 159 to 1475 kg/m2s, were tested. The test module was well insulated to maintain adiabatic conditions. The experimental results were compared to those from a micro-pin-fin array having similar size and geometrical arrangement but a square cross-section. The circular micro-pin-fins were seen to yield a significantly lower pressure drop than the square micro-pin-fins. The present experimental results were also compared with the predictions of several friction factor correlations as well as the results from a three-dimensional numerical analysis. Neither was able to accurately predict the experimental data.

Study of Friction Factor and Equivalent Diameter Correlations for Annular Flow of Non-Newtonian Drilling Fluids

1987 ◽  
Vol 109 (4) ◽  
pp. 200-205 ◽  
Author(s):  
T. B. Jensen ◽  
M. P. Sharma
Keyword(s):  
Pressure Drop ◽  
Friction Factor ◽  
Field Data ◽  
Equivalent Diameter ◽  
Drilling Fluids ◽  
Pressure Gradients ◽  
Bingham Plastic ◽  
Frictional Pressure Drop ◽  
Friction Factors ◽  
Friction Factor Correlation

Published annular pressure drop field data have been compared with values predicted by the Bingham plastic and power law models. Several different equivalent diameter equations and friction factor correlations were utilized to estimate the frictional pressure gradients. The estimated frictional pressure drop gradients were then compared with the experimental gradients statistically to determine which combination of friction factor correlation and equivalent diameter equation predicted the experimental data best. Finally, new correlations for friction factors were developed. These new correlations predict the field data better than previously published correlations.

scholarly journals Numerical Evaluation of Potential Catalyst Savings for Ventilation Air Methane Catalytic Combustion in Helical Coil Reactors with Selective Wall Coating

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 380 ◽  
Author(s):  
Jundika C. Kurnia ◽  
Benitta A. Chaedir ◽  
Desmond C. Lim ◽  
Lianjun Chen ◽  
Lishuai Jiang ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Cross Section ◽  
Catalytic Combustion ◽  
Circular Cross Section ◽  
Energy Resource ◽  
Mining Operation ◽  
Superior Performance ◽  
Helical Coil ◽  
Net Energy ◽  
Reaction Performance

During active mining operation of a gassy underground mine, large amounts of methane will be released from the mine ventilation shaft. To eliminate the harmful effects of this ventilation air methane and minimize the wastage of this potential energy resource, considerable effort has been devoted to converting this alternative fuel using catalytic combustion. This study numerically investigated the reaction performance of ventilation air methane (VAM) in helical coil tubes of various configurations utilizing a computational fluid dynamics (CFDs) approach. Several key factors affecting the catalytic combustion performance such as curvature, inlet Reynolds number, and cross-section aspect ratio were evaluated. Recalling the high cost of the catalyst used in this reaction—platinum—optimization of catalyst usage by implementing selective catalyst coating was conducted and investigated. For evaluation purposes, the reaction performance of the helical coil tube was compared to its straight counterpart. The results gave a firm confirmation of the superior performance of the helical coil tube compared to the straight one. In addition, it was found that the selective inner wall coating in the circular cross-section at a higher Reynolds number gave rise to the highest figure of merit (FoM), defined as the net energy produced per mg of catalyst platinum.

Two-Phase Flow (Oil and Water) in Ducts with the Elliptical Cross-Section: Modeling and Simulation

2019 ◽  
Vol 24 ◽  
pp. 61-75
Author(s):  
J.L. de Oliveira ◽  
A.G. Barbosa de Lima ◽  
R. Pereira Ramos ◽  
H. Luma Fernandes Magalhães ◽  
W.R. Gomes dos Santos ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Aspect Ratio ◽  
Cross Section ◽  
Operating Cost ◽  
Circular Cross Section ◽  
Elliptical Cross Section ◽  
Two Phase ◽  
Elliptical Cross ◽  
Ansys Cfx ◽  
Velocity Pressure

In the oil industry, pipelines (circular ducts) are widely used for the transportation of oil and yours derived. Because of their advantages, such as low operating cost and increased safety during transportation, pipelines have become indispensable for transporting oil in large quantities and for long distances. As an alternative to this problem, the transport of oil and water can be accomplished using ducts with an elliptical cross-section. Thus, this work has the objective of studying the flow of oil and water in cylindrical ducts with an elliptical cross-section by using the Ansys CFX software. Results of the velocity, pressure and volumetric fraction distributions of the oil and water phases are presented and analyzed. By applying the same inlet velocity to oil and water, revealed that the elliptical duct, with aspect ratio equal to 5.0, has a pressure drop less (84.2%) than the pressure drop obtained for one duct of circular cross-section (aspect ratio equal to 1.0).

An Experimental Study of Heat Transfer and Pressure Drop on the Bend Surface of a U-Duct

2010 ◽  
Author(s):  
Tareq Salameh ◽  
Bengt Sunden
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Reynolds Number ◽  
Pressure Drop ◽  
Friction Factor ◽  
Cross Section ◽  
Outer Wall ◽  
Cross Section Area ◽  
Section Area ◽  
The Cross

This work concerns an experimental study of pressure drop and heat transfer for turbulent flow inside a U-duct. Such duct geometries can be found in many engineering applications where cooling air extracts heat from hot internal walls of the duct, e.g., passage cooling inside gas turbine blades. Both friction factors and convective heat transfer coefficients were measured inside a U-duct for three different cases, namely (a) the smooth straight part, (b) the smooth bend (turn) part, and (c) a rough (ribbed) bend (turn) part. The details of the duct geometry were as follows: the cross section area of the straight part was 50×50 mm2, the inside length of the bend part 240 mm, the cross section area of the rib was 5×5 mm2 and the rib height-to-hydraulic diameter ratio, e/Dh, was 0.1. The Reynolds number was varied from 8,000 to 20,000. The test rig has been built in such a way that various experimental setups can be handled as the bend (turn) part of the U-duct can easily be removed and the rib configuration can be changed. Both the U-duct and the rib were made from plexiglass material to allow optical access for measuring the surface temperature by using a high-resolution measurement technique based on narrow band thermochromic liquid crystals (TLC R35C5W) and a CCD camera placed facing the bend (turn) part of the U-duct. The calibration of the TLC is based on the hue-based color decomposition system using an in-house designed calibration box. The rib was placed transversely to the direction of the main flow at the outer wall of the bend (turn) part where the wall was heated by an electrical heater. The friction factor ratio and the heat transfer enhancement ratio for case (c) at a Reynolds number of 20,000 were 48.75 and 2.66, respectively. It is found that the presence of the rib increases the heat transfer coefficient on the outer wall of the bend part (tip of side U-duct). The uncertainties were 3% and 6% for the Nusselt number and friction factor, respectively.

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