Editing Lambert W function (section)

=== Viscous flows ===
Granular and debris flow fronts and deposits, and the fronts of viscous fluids in natural events and in laboratory experiments can be described by using the Lambert–Euler omega function as follows:
: <math>H(x)= 1 + W \left((H(0) -1) e^{(H(0)-1)-\frac{x}{L}}\right),</math>
where {{math|''H''(''x'')}} is the debris flow height, {{mvar|x}} is the channel downstream position, {{mvar|L}} is the unified model parameter consisting of several physical and geometrical parameters of the flow, flow height and the hydraulic pressure gradient.

In [[pipe flow]], the Lambert W function is part of the explicit formulation of the [[Colebrook equation]] for finding the [[Darcy friction factor]]. This factor is used to determine the pressure drop through a straight run of pipe when the flow is [[turbulent]].<ref name="AAMore">{{cite journal |title = Analytical solutions for the Colebrook and White equation and for pressure drop in ideal gas flow in pipes |author = More, A. A. |journal = Chemical Engineering Science |volume = 61 |pages = 5515–5519 |year = 2006 |issue = 16 |doi = 10.1016/j.ces.2006.04.003 |bibcode = 2006ChEnS..61.5515M }}</ref>