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.

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.

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.

Friction Factor Directly From Roughness Measurements

2001 ◽  
Author(s):  
Elling Sletfjerding ◽  
Jon Steinar Gudmundsson
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Power Spectrum ◽  
Friction Factor ◽  
High Reynolds Number ◽  
Gas Flow ◽  
Relative Roughness ◽  
High Reynolds ◽  
Friction Factor Correlation ◽  
Roughness Measurements

Abstract Pressure drop experiments on natural gas flow in 150 mm pipes at 80 to 120 bar pressure and high Reynolds number were carried out for pipes smooth to rough surfaces. The roughness was measured with an accurate stylus instrument and analyzed using fractal methods. Using a similar approach to that of Nikuradse the measured friction factor was related to the measured roughness values. Taking the value of the relative roughness and dividing it by the slope of the power spectrum of the measured roughness, a greatly improved fit with the measured friction factor was obtained. Indeed, a new friction factor correlation was obtained, but now formulated in terms of direct measurement of roughness.

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.

Evaluation of Frictional Pressure Drop Correlations During Flow Boiling of Refrigerants in Micro-Fin Tubes

2020 ◽  
Author(s):  
Weiyu Tang ◽  
Wei Li ◽  
Jianxin Zhou
Keyword(s):  
Pressure Drop ◽  
Flow Boiling ◽  
Predictive Ability ◽  
Operating Conditions ◽  
Commercial Application ◽  
Equivalent Diameter ◽  
Specific Work ◽  
Frictional Pressure Drop ◽  
Data Points ◽  
Fin Tubes

Abstract Due to the widely commercial application of micro-fin tube and eco-friendly refrigerants, more general frictional pressure drop correlations is demanded for better prediction, and this study is aimed at compared existing correlations and provide guides for the furthermore improvement. Experimental data points for frictional pressure drop during flow boiling of refrigerants in horizontal micro-fin tubes were extracted from literature and our previous experimental work to evaluate numerous existing frictional pressure drop correlations and specify their applicability to meet the urgent demand of extensive application of eco-friendly refrigerants. The database consists of 949 data points covering eleven refrigerants (R1233zd(Z), R410A, R1234ze(E), R410A, R22, R32, R1234ze(Z), R22, R134a, R245fa and R1234yf included), and the involved operation conditions are as follows: mass velocity 94–888 kg m−2s−1, vapor quality 0.04–0.99, heat flux 3.9–85.2 kW m−2, and equivalent diameter 2.12–11.84mm. Eight existing general frictional pressure drop correlation including Cavallini et al., Kuo and Wang, Wongsangam et al. and Rollman and Spindler correlation were evaluated against the present database. In addition, the Churchill et al. model was employed in several correlation to improve their performance. It was found that none of these correlations was capable of providing a satisfactory prediction for a general operation condition. A detailed predictive ability of these correlation against specific work fluids were given for reference, and their individual parametric-trend predictive ability were also compared under varied operating conditions using several datasets.

Optimized Condition for Pairing of Different Friction Factor and Viscosity Equations for the Frictional Pressure Drop of R22 and R290

2019 ◽  
Vol 27 (04) ◽  
pp. 1950037
Author(s):  
Qais Abid Yousif ◽  
Normah Mohd-Ghazali ◽  
Agus Sunjarianto Pamitran ◽  
Yushazaziah Mohd-Yunos
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Friction Factor ◽  
Environmentally Friendly ◽  
Two Phase ◽  
Frictional Pressure Drop ◽  
Multi Objective Genetic Algorithm ◽  
Percentage Difference ◽  
The Many ◽  
Small Channels

Accurate prediction of the friction factor and consequently the pressure drop of two-phase flow in small channels is still an issue. Many correlations exist for the determination of the viscosity and the friction factor that appear in the frictional pressure drop and their combination often determined the degree of disagreements between the experimental data and predicted outcomes. Demands for environmentally friendly refrigerants have further posed a challenge to find compatible alternatives with as good a performance as the current coolants. Despite the many available correlations developed to date, many more are studied in effort to reduce the discrepancies. This paper presents the outcomes of a study comparing the optimized conditions when three different viscosity equations are paired with eight different friction factor correlations to minimize the frictional pressure drop. The approach used multi-objective genetic algorithm (MOGA) to assist in selecting the best pairing. Comparison is then completed with available experimental data. The study showed that the Blasius friction factor paired with the Dukler viscosity produced the least percentage difference for R22, while when paired with the McAdams viscosity produced a lower difference for R290, an environmentally friendly refrigerant being considered to replace R22.

Frictional Pressure Drop Correlations for Single-Phase Flow, Condensation, and Evaporation in Microfin Tubes

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Zan Wu ◽  
Bengt Sundén
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Single Phase ◽  
Flow Boiling ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Frictional Pressure Drop ◽  
Friction Factors ◽  
Flow Condensation ◽  
Microfin Tubes

Experimental single-phase, condensation, and evaporation (flow boiling) pressure drop data from the literature and our previous studies were collected to evaluate previous frictional pressure drop correlations for horizontal microfin tubes of different geometries. The modified Ravigururajan and Bergles correlation, by adopting the Churchill model to calculate the smooth-tube friction factor and by using the hydraulic diameter in the Reynolds number, can predict single-phase turbulent frictional pressure drop data relatively well. Eleven pressure drop correlations were evaluated by the collected database for condensation and evaporation. Correlations originally developed for condensation and evaporation in smooth tubes can be suitable for microfin tubes if the friction factors in the correlations were calculated by the Churchill model to include microfin effects. The three most accurate correlations were recommended for condensation and evaporation in microfin tubes. The Cavallini et al. correlation and the modified Friedel correlation can give good predictions for both condensation and evaporation. However, some inconsistencies were found, even for the recommended correlations.

Mixed Convective Low Flow Pressure Drop in Vertical Rod Assemblies: I—Predictive Model and Design Correlation

1989 ◽  
Vol 111 (4) ◽  
pp. 956-965 ◽  
Author(s):  
K. Y. Suh ◽  
N. E. Todreas ◽  
W. M. Rohsenow
Keyword(s):  
Pressure Drop ◽  
Mixed Convection ◽  
Wide Spectrum ◽  
Natural Circulation ◽  
Reynolds Numbers ◽  
Low Flow ◽  
Spatial Average ◽  
Frictional Pressure Drop ◽  
Friction Factors ◽  
Geometric Arrangements

A predictive theory has been developed for rod bundle frictional pressure drop characteristics under laminar and transitional mixed convection conditions on the basis of the intraassembly and intrasubchannel flow redistributions due to buoyancy for a wide spectrum of radial power profiles and for the geometric arrangements of practical design interest. Both the individual subchannel correlations and overall bundle design correlations have been formulated as multipliers applied to the isothermal friction factors at the same Reynolds numbers. Standard and modified subchannel friction factors have been obtained to be used with spatial-average and bulk-mean densities, respectively. A correlating procedure has been proposed to assess the effects of interacting subchannel flows, developing mixed convective flow, wire wrapping, power skew, rod number, and transition from laminar flow. In contrast to forced convection behavior, a strong rod number effect is present under mixed convection conditions in bundle geometries. The results of this study are of design importance in natural circulation conditions because the mixed convection frictional pressure losses exceed the corresponding isothermal values at the same Reynolds numbers.

Two-Phase Flow through Corrugated U-Tube

2010 ◽  
Vol 224 (11) ◽  
pp. 2408-2417 ◽  
Author(s):  
B Shannak ◽  
R Damseh ◽  
M Al-Odat ◽  
M Al-Shannag ◽  
A Azzi
Keyword(s):  
Pressure Drop ◽  
Friction Factor ◽  
Two Phase Flow ◽  
Complex Geometry ◽  
Geometrical Parameters ◽  
Phase Flow ◽  
Two Phase ◽  
Frictional Pressure Drop ◽  
System Pressure ◽  
Inner Diameter

New measurements of the frictional pressure drop of air—water two-phase flow in a flexible corrugated U-tube have been carried out. Experiments were performed under the following conditions of two-phase parameters: mass flux of 300—800 kg/m2 s, gas quality of 1—60 per cent, and system pressure of 3—7 bar. The inner diameter of the U-tubes tested was 40 mm, with a ratio of curvature radius to inner diameter varying from 3 to 7.5. The results demonstrate that the two-phase flow resistance, energy dissipation, friction losses, and interaction of the two phases in flexible corrugated U-tubes are perceptible about two to five times greater than those in smooth U-tubes. Hence, the two-phase friction factor of such tubes increases from 0.65 to 1.4, depending on the influencing flow and geometrical parameters. The available correlations in the open literature present a similar trend and behaviour. However, they predict the data presented poorly because of the complex geometry of the flexible corrugated U-tube. Based on the energy balance and the presented experimental results, a new model has been developed to calculate the frictional two-phase pressure drop and hence the friction factor of the flexible U-tube. The model includes the relevant primary parameter, fits the experimental data well, and is sufficiently accurate for engineering purposes. The standard deviation of the data is less than 7 per cent. The reported results enable a practical design with standard products and optimization of the geometry of the flexible corrugated U-tube for specific conditions.

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