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

Abstract

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.

Accurate and Efficient Explicit Approximations of the Colebrook Flow Friction Equation Based on the Wright ω-Function: Reply to Discussion

“…In our recent paper [1] we found that one pair of parentheses is missing in Equation (2). The corrected Equation (2) of the commented article [1] is here given as Equation 1:…”

“…The nature of these errors is typographical and does not affect other formulas or findings. We apologize to the readers for any inconvenience caused by these two typographical errors, and we want to thank the authors of the discussion [2] for pointing out the errors in the second here corrected equation.…”

“…As reported in the discussion [2], in Equation (11) of the commented paper [1], parentheses are also missing, while the correct version is given by Equation (A7), in Appendix A of the commented paper [1]. The corrected Equation (11) of the commented article [1] is here given as Equation 2:…”

“…This reply provides responses to the discussion related to the commented article [1]. Recently we published a paper [1], for which we received an interesting discussion [2] and we would like to thank the authors for the useful comments. Our reply will offer two corrections of typographical errors in respect to our commented article [1], then provide a few comments in respect to the discussion [2].…”

“…Recently we published a paper [1], for which we received an interesting discussion [2] and we would like to thank the authors for the useful comments. Our reply will offer two corrections of typographical errors in respect to our commented article [1], then provide a few comments in respect to the discussion [2]. Finally, one improved version of approximations of the Colebrook equation for flow friction will be presented, which is also based on the Wright ω-function.…”