Lambert W function in hydraulic problems


== Abstract ==

<p>Darcy&rsquo;s flow friction factor is expressed in implicit form in some of the relations such as Colebrook&rsquo;s and have to be solved by iteration procedure because the unknown friction factor appears on both sides of the equation. Lambert W function is implicitly elementary but is not, itself, an elementary function. Implicit form of the Lambert W function allows us to transform other implicit functions in explicit form without any kind of approximations or simplifications involved. But unfortunately, the Lambert W function itself cannot be solved easily without approximation. Two original transformations in explicit form of Colebrook&rsquo;s relation using Lambert W function will also be shown. Here will be shown efficient procedure for approximate solutions of the transformed relations.</p>



== Full document ==
<pdf>Media:Draft_Brkic_310967562-6632-document.pdf</pdf>