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Explicit Determinations of the Colebrook Equation for the Flow Friction Factor by Statistical Analysis
Author(s) -
Heydari Amir,
Narimani Elhameh,
Pakniya Fatemeh
Publication year - 2015
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.201400590
Subject(s) - mathematics , turbulence , reynolds number , flow (mathematics) , approximation error , factor (programming language) , set (abstract data type) , simple (philosophy) , domain (mathematical analysis) , cover (algebra) , friction factor , mathematical analysis , mechanics , geometry , computer science , physics , engineering , programming language , philosophy , epistemology , mechanical engineering
The implicit Colebrook equation is considered as a fundamental equation for estimating the friction factor for turbulent flows in pipes. A large number of simple and accurate explicit approximations cover just a limited area of turbulent regime inside rough or smooth pipes. Here, three explicit approximations of the friction factor were determined. The friction factor data were fitted into polynomials using the response surface design of Minitab® software. To reduce the relative error of the first approximation compared with the implicit Colebrook equation, the domain was divided into two regions based on the Reynolds number ( Re ). To compare the accuracy and complexity of the approximations with existing relations, advanced comparison analysis based on the relative error was performed. The second set of approximations defined in two ranges of Re demonstrated high accuracy and a satisfying complexity index.