Does Moody Diagram used for calculating energy losses in pipes suitable for all conditions?
Darcy-Weisbach equation combined with the Moody Diagram is the accepted method to calculate energy losses resulting from fluid motion in pipes and other closed conduits. However, the Moody Diagram may not be suitable for usage in some conditions. For instance, the curve at transition region between laminar and fully turbulent rough pipe flow is applicable for pipes with interior roughness comparable to iron. Moreover, owing to the difficulty in determining pipe roughness, the accuracy of Moody Diagram is only about plus or minus 15%. This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.
