For turbulent Newtonian flow

In the same way as there are many equations for predicting friction factor for turbulent Newtonian flow, there are munerous equations for time-independent non-Newtonian fluids most of these are based on dimensional considerations combined with experimental observations [Govier and Aziz, 1982 Heywood and Cheng, 1984]. There is a preponderance of correlations based on the power-law fluid behaviour and additionally some expressions are available for Bingham plastic fluids [Tomita, 1959 Wilson and Thomas, 1985], Here only a selection of widely used and proven methods is presented. 

This agrees with the expression for turbulent Newtonian flow when the veloeity profile is assiuned to be approximately flat. 

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