The Experts below are selected from a list of 21723 Experts worldwide ranked by ideXlab platform
Jean Loup Robert - One of the best experts on this subject based on the ideXlab platform.
-
discussion of accurate and efficient explicit approximations of the colebrook flow friction Equation based on the wright ω function by dejan brki c and pavel praks mathematics 2019 7 34 doi 10 3390 math7010034
Mathematics, 2019Co-Authors: Lotfi Zeghadnia, Bachir Achour, Jean Loup RobertAbstract:The Colebrook-White Equation is often used for calculation of the friction factor in turbulent regimes; it has succeeded in attracting a great deal of attention from researchers. The Colebrook–White Equation is a complex Equation where the computation of the friction factor is not direct, and there is a need for trial-error methods or graphical solutions; on the other hand, several researchers have attempted to alter the Colebrook-White Equation by explicit formulas with the hope of achieving zero-percent (0%) maximum deviation, among them Dejan Brkic and Pavel Praks. The goal of this paper is to discuss the results proposed by the authors in their paper:” Accurate and Efficient Explicit Approximations of the Colebrook Flow Friction Equation Based on the Wright ω-Function” and to propose more accurate formulas.
-
discussion of accurate and efficient explicit approximations of the colebrook flow friction Equation based on the wright ω function by dejan brki c and pavel praks mathematics 2019 7 34 doi 10 3390 math7010034
Mathematics, 2019Co-Authors: Lotfi Zeghadnia, Bachir Achour, Jean Loup RobertAbstract:The Colebrook-White Equation is often used for calculation of the friction factor in turbulent regimes; it has succeeded in attracting a great deal of attention from researchers. The Colebrook–White Equation is a complex Equation where the computation of the friction factor is not direct, and there is a need for trial-error methods or graphical solutions; on the other hand, several researchers have attempted to alter the Colebrook-White Equation by explicit formulas with the hope of achieving zero-percent (0%) maximum deviation, among them Dejan Brkic and Pavel Praks. The goal of this paper is to discuss the results proposed by the authors in their paper:” Accurate and Efficient Explicit Approximations of the Colebrook Flow Friction Equation Based on the Wright ω-Function” and to propose more accurate formulas.
-
Discussion of “Accurate and Efficient Explicit Approximations of the Colebrook Flow Friction Equation Based on the Wright ω-Function” by DejanBrkić; and Pavel Praks, Mathematics 2019, 7, 34; doi:10.3390/math7010034
MDPI AG, 2019Co-Authors: Lotfi Zeghadnia, Bachir Achour, Jean Loup RobertAbstract:The Colebrook-White Equation is often used for calculation of the friction factor in turbulent regimes; it has succeeded in attracting a great deal of attention from researchers. The Colebrook–White Equation is a complex Equation where the computation of the friction factor is not direct, and there is a need for trial-error methods or graphical solutions; on the other hand, several researchers have attempted to alter the Colebrook-White Equation by explicit formulas with the hope of achieving zero-percent (0%) maximum deviation, among them Dejan Brkić and Pavel Praks. The goal of this paper is to discuss the results proposed by the authors in their paper:” Accurate and Efficient Explicit Approximations of the Colebrook Flow Friction Equation Based on the Wright ω-Function” and to propose more accurate formulas
-
Explicit solutions for turbulent flow friction factor: A review, assessment and approaches classification
Elsevier, 2019Co-Authors: Lotfi Zeghadnia, Jean Loup Robert, Bachir AchourAbstract:The Colebrook –white Equation is widely used in many fields, like civil engineering for calculation of water distribution systems and in all fields of engineering where fluid flow can be occurred. Numerous formulas have been proposed since 1947 in order to simplify the computation of the friction factor, to avoid the iterative procedures methods and to alter the Colebrook-White Equation in practice. most of the existing explicit formulas for computation of the friction factor for turbulent flow in rough pipes proposed are cited, where thirty three “33” Equations have been inventoried. The goal of this paper is to assess the accuracy of each model and to propose an arrangement from the best to the lower accuracy according to a proposed method combined of three criteria which are: simplicity of the formula, maximum deviations and the coverage of the entire range of Moody diagram. Keywords: Friction factor, Explicit solutions, Moody diagram, Maximum deviation, Turbulent flo
Lotfi Zeghadnia - One of the best experts on this subject based on the ideXlab platform.
-
discussion of accurate and efficient explicit approximations of the colebrook flow friction Equation based on the wright ω function by dejan brki c and pavel praks mathematics 2019 7 34 doi 10 3390 math7010034
Mathematics, 2019Co-Authors: Lotfi Zeghadnia, Bachir Achour, Jean Loup RobertAbstract:The Colebrook-White Equation is often used for calculation of the friction factor in turbulent regimes; it has succeeded in attracting a great deal of attention from researchers. The Colebrook–White Equation is a complex Equation where the computation of the friction factor is not direct, and there is a need for trial-error methods or graphical solutions; on the other hand, several researchers have attempted to alter the Colebrook-White Equation by explicit formulas with the hope of achieving zero-percent (0%) maximum deviation, among them Dejan Brkic and Pavel Praks. The goal of this paper is to discuss the results proposed by the authors in their paper:” Accurate and Efficient Explicit Approximations of the Colebrook Flow Friction Equation Based on the Wright ω-Function” and to propose more accurate formulas.
-
discussion of accurate and efficient explicit approximations of the colebrook flow friction Equation based on the wright ω function by dejan brki c and pavel praks mathematics 2019 7 34 doi 10 3390 math7010034
Mathematics, 2019Co-Authors: Lotfi Zeghadnia, Bachir Achour, Jean Loup RobertAbstract:The Colebrook-White Equation is often used for calculation of the friction factor in turbulent regimes; it has succeeded in attracting a great deal of attention from researchers. The Colebrook–White Equation is a complex Equation where the computation of the friction factor is not direct, and there is a need for trial-error methods or graphical solutions; on the other hand, several researchers have attempted to alter the Colebrook-White Equation by explicit formulas with the hope of achieving zero-percent (0%) maximum deviation, among them Dejan Brkic and Pavel Praks. The goal of this paper is to discuss the results proposed by the authors in their paper:” Accurate and Efficient Explicit Approximations of the Colebrook Flow Friction Equation Based on the Wright ω-Function” and to propose more accurate formulas.
-
Discussion of “Accurate and Efficient Explicit Approximations of the Colebrook Flow Friction Equation Based on the Wright ω-Function” by DejanBrkić; and Pavel Praks, Mathematics 2019, 7, 34; doi:10.3390/math7010034
MDPI AG, 2019Co-Authors: Lotfi Zeghadnia, Bachir Achour, Jean Loup RobertAbstract:The Colebrook-White Equation is often used for calculation of the friction factor in turbulent regimes; it has succeeded in attracting a great deal of attention from researchers. The Colebrook–White Equation is a complex Equation where the computation of the friction factor is not direct, and there is a need for trial-error methods or graphical solutions; on the other hand, several researchers have attempted to alter the Colebrook-White Equation by explicit formulas with the hope of achieving zero-percent (0%) maximum deviation, among them Dejan Brkić and Pavel Praks. The goal of this paper is to discuss the results proposed by the authors in their paper:” Accurate and Efficient Explicit Approximations of the Colebrook Flow Friction Equation Based on the Wright ω-Function” and to propose more accurate formulas
-
Explicit solutions for turbulent flow friction factor: A review, assessment and approaches classification
Elsevier, 2019Co-Authors: Lotfi Zeghadnia, Jean Loup Robert, Bachir AchourAbstract:The Colebrook –white Equation is widely used in many fields, like civil engineering for calculation of water distribution systems and in all fields of engineering where fluid flow can be occurred. Numerous formulas have been proposed since 1947 in order to simplify the computation of the friction factor, to avoid the iterative procedures methods and to alter the Colebrook-White Equation in practice. most of the existing explicit formulas for computation of the friction factor for turbulent flow in rough pipes proposed are cited, where thirty three “33” Equations have been inventoried. The goal of this paper is to assess the accuracy of each model and to propose an arrangement from the best to the lower accuracy according to a proposed method combined of three criteria which are: simplicity of the formula, maximum deviations and the coverage of the entire range of Moody diagram. Keywords: Friction factor, Explicit solutions, Moody diagram, Maximum deviation, Turbulent flo
Chetan T. Goudar - One of the best experts on this subject based on the ideXlab platform.
-
explicit reformulation of the colebrook white Equation for turbulent flow friction factor calculation
Industrial & Engineering Chemistry Research, 2007Co-Authors: Jagadeesh R Sonnad, Chetan T. GoudarAbstract:In this paper, we present an improvement of a mathematically equivalent representation of the Colebrook−White (CW) Equation to compute friction factors for turbulent flow in rough pipes. This new form is simple and very well-suited for accurately estimating the friction factor, because no iterative calculations are necessary. Specifically, the friction factor is expressed as the sum of known simple functions and an unknown correction term. This correction term satisfies an auxiliary Equation that can be accurately and easily solved with predictable error bounds over the complete range of pipe roughness and Reynolds number values encountered in practice. The simplest case, with the unknown correction term set to zero, resulted in friction factor estimates with errors of <1%. A simple linear approximation of the correction term resulted in a maximum error of 3.64 × 10-4%, whereas friction factor estimates from a continued-fractions-based approximation had a maximum error of 1.04 × 10-10%. These maximum erro...
-
turbulent flow friction factor calculation using a mathematically exact alternative to the colebrook white Equation
Journal of Hydraulic Engineering, 2006Co-Authors: Jagadeesh R Sonnad, Chetan T. GoudarAbstract:We present a novel, mathematically equivalent representation of the Colebrook–White Equation to compute friction factor for turbulent flow in rough pipes. This new form is simple, no iterative calculations are necessary, and is well suited for accurate friction factor estimation. A limiting case of this Equation provided friction factor estimates with a maximum absolute error of 0.029 and a maximum percentage error of 1% over a 20×500 grid of e∕D and R values ( 10−6 ⩽e∕D⩽5× 10−2 ; 4× 103
-
constraints for using lambert w function based explicit colebrook white Equation
Journal of Hydraulic Engineering, 2004Co-Authors: Jagadeesh R Sonnad, Chetan T. GoudarAbstract:We analyze the general applicability of a recent explicit expression of the Colebrook.White Equation for turbulent flow friction factor calculation. This explicit expression, which is based on the Lambert \IW\N function, is characterized by an exponential term which imposes restrictions on its use. These constraints have been expressed in terms of pipe roughness (ϵ/\ID\N) and the Reynolds number R that are required for friction factor calculation. These constraints were determined as 8.0666 ln(R) + (ϵ/\ID\N)R<721.97 and 8.0666 ln(R) + (ϵ/\ID\N)R<5731.83, respectively, for machines using single precision and double precision computations. Using the Lambert W function, an explicit Equation relating Rand ϵ/\ID\N was derived at the limiting case which allowed for a graphical representation of the applicability of the explicit form of the Colebrook.White Equation in the Rversus ϵ/\ID\N space. Before computing friction factors using the explicit Colebrook-White Equation, a quick check must be performed to see if the desired combination of Rand ϵ/\ID\N values satisfies the applicable constraint mentioned above.
Bachir Achour - One of the best experts on this subject based on the ideXlab platform.
-
discussion of accurate and efficient explicit approximations of the colebrook flow friction Equation based on the wright ω function by dejan brki c and pavel praks mathematics 2019 7 34 doi 10 3390 math7010034
Mathematics, 2019Co-Authors: Lotfi Zeghadnia, Bachir Achour, Jean Loup RobertAbstract:The Colebrook-White Equation is often used for calculation of the friction factor in turbulent regimes; it has succeeded in attracting a great deal of attention from researchers. The Colebrook–White Equation is a complex Equation where the computation of the friction factor is not direct, and there is a need for trial-error methods or graphical solutions; on the other hand, several researchers have attempted to alter the Colebrook-White Equation by explicit formulas with the hope of achieving zero-percent (0%) maximum deviation, among them Dejan Brkic and Pavel Praks. The goal of this paper is to discuss the results proposed by the authors in their paper:” Accurate and Efficient Explicit Approximations of the Colebrook Flow Friction Equation Based on the Wright ω-Function” and to propose more accurate formulas.
-
discussion of accurate and efficient explicit approximations of the colebrook flow friction Equation based on the wright ω function by dejan brki c and pavel praks mathematics 2019 7 34 doi 10 3390 math7010034
Mathematics, 2019Co-Authors: Lotfi Zeghadnia, Bachir Achour, Jean Loup RobertAbstract:The Colebrook-White Equation is often used for calculation of the friction factor in turbulent regimes; it has succeeded in attracting a great deal of attention from researchers. The Colebrook–White Equation is a complex Equation where the computation of the friction factor is not direct, and there is a need for trial-error methods or graphical solutions; on the other hand, several researchers have attempted to alter the Colebrook-White Equation by explicit formulas with the hope of achieving zero-percent (0%) maximum deviation, among them Dejan Brkic and Pavel Praks. The goal of this paper is to discuss the results proposed by the authors in their paper:” Accurate and Efficient Explicit Approximations of the Colebrook Flow Friction Equation Based on the Wright ω-Function” and to propose more accurate formulas.
-
Discussion of “Accurate and Efficient Explicit Approximations of the Colebrook Flow Friction Equation Based on the Wright ω-Function” by DejanBrkić; and Pavel Praks, Mathematics 2019, 7, 34; doi:10.3390/math7010034
MDPI AG, 2019Co-Authors: Lotfi Zeghadnia, Bachir Achour, Jean Loup RobertAbstract:The Colebrook-White Equation is often used for calculation of the friction factor in turbulent regimes; it has succeeded in attracting a great deal of attention from researchers. The Colebrook–White Equation is a complex Equation where the computation of the friction factor is not direct, and there is a need for trial-error methods or graphical solutions; on the other hand, several researchers have attempted to alter the Colebrook-White Equation by explicit formulas with the hope of achieving zero-percent (0%) maximum deviation, among them Dejan Brkić and Pavel Praks. The goal of this paper is to discuss the results proposed by the authors in their paper:” Accurate and Efficient Explicit Approximations of the Colebrook Flow Friction Equation Based on the Wright ω-Function” and to propose more accurate formulas
-
Explicit solutions for turbulent flow friction factor: A review, assessment and approaches classification
Elsevier, 2019Co-Authors: Lotfi Zeghadnia, Jean Loup Robert, Bachir AchourAbstract:The Colebrook –white Equation is widely used in many fields, like civil engineering for calculation of water distribution systems and in all fields of engineering where fluid flow can be occurred. Numerous formulas have been proposed since 1947 in order to simplify the computation of the friction factor, to avoid the iterative procedures methods and to alter the Colebrook-White Equation in practice. most of the existing explicit formulas for computation of the friction factor for turbulent flow in rough pipes proposed are cited, where thirty three “33” Equations have been inventoried. The goal of this paper is to assess the accuracy of each model and to propose an arrangement from the best to the lower accuracy according to a proposed method combined of three criteria which are: simplicity of the formula, maximum deviations and the coverage of the entire range of Moody diagram. Keywords: Friction factor, Explicit solutions, Moody diagram, Maximum deviation, Turbulent flo
Monge Freile, Marlon Fernando - One of the best experts on this subject based on the ideXlab platform.
-
El bambú (Guadua angustifolia spp.) como alternativa de conducción para un sistema de riego por multicompuertas
'Universidad Nacional Agraria la Molina', 2018Co-Authors: Monge Freile, Marlon FernandoAbstract:Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Recursos HídricosEn el presente trabajo se propone utilizar el bambú como alternativa de conducción para un sistema de riego por multicompuertas, los altos costos que generan las tuberías de conducción para el riego han permitido que muchos agricultores no cuenten con estos implementos, es por ello que en esta investigación se tuvo como objetivo utilizar al bambú como tubería de conducción en zonas donde abunda esta especie vegetal, caracterizando hidráulicamente al bambú, para ello se determinó la rugosidad, su máxima presión de trabajo, se elaboró una guía para la selección de diámetros de bambú en condiciones de pendiente y en condiciones de carga de presión. El valor de rugosidad absoluta del bambú obtenido mediante la ecuación de Colebrook – White, es de Ks = 0.0161 metros, el coeficiente de rugosidad por Hazen – Williams, es de C = 50 y el coeficiente de rugosidad de Manning, es de n = 0.0232, estos coeficientes podrán ser utilizados para el diseño de tuberías de bambú, utilizando cualquiera de las ecuaciones ya mencionadas. También se comparó los resultados de pérdida de carga estimados por los tres métodos, versus los valores medidos obtenidos en laboratorio, se determinó mediante indicadores estadísticos, como el error cuadrático medio “ECM” y el coeficiente de eficiencia “CE”, estos indicadores no presentaron diferencias significativas, aunque se observó que el método de Hazen- Williams obtuvo un mayor acercamiento que los demás métodos, del análisis de velocidades se puede afirmar que a partir de velocidades superiores a 0.8 m/s, se produce un cambio en el comportamiento de la pérdida de carga, aumentando potencialmente. Respecto a la máxima presión de trabajo del bambú, se determinó que soporta presiones hasta de 30 PSI o 20 mca aproximadamente, a partir de presiones superiores a las mencionadas, se producen fugas en las uniones.In the present work it is proposed to use bamboo as an alternative for conduction material for a floogates irrigation system, the high costs generated by the irrigation pipes have allowed many farmers not to have these implements, which is why that in this investigation the objective was to use bamboo as a pipeline in areas where this plant species abounds, hydraulically characterizing the bamboo, for this the roughness was determined, its maximum working pressure, a guide was prepared for the selection of diameters of bamboo in conditions of slope and under conditions of pressure loading. The absolute rugosity value of the bamboo obtained by the Colebrook - White Equation is Ks = 0.0161 meters, the roughness coefficient by Hazen - Williams is C = 50 and the roughness coefficient of Manning is n = 0.0232, these coefficients can be used for the design of bamboo pipes, using any of the aforementioned Equations. We also compared the results of load loss estimated by the three methods, versus the measured values obtained in the laboratory, was determined by statistical indicators, such as the mean square error "MSE" and the coefficient of efficiency "CE", these indicators did not present significant differences, although it was observed that the Hazen-Williams method obtained a greater approach than the other methods, from the velocity analysis it can be affirmed that from speeds higher than 0.8 m / s, a change in the behavior of the loss of charge, potentially increasing. Regarding the maximum working pressure of the bamboo, it was determined that the bamboo supports pressures up to 30 PSI or 20 mwc approximately, from pressures higher than those mentioned, leaks occur in the joints.Tesi