The Moody chart, Fig. 6.13, is best for finding head loss (or p) when Q, V, d,

The Moody chart, Fig. 6.13, is best for finding head loss (or Δp) when Q, V, d, and L are known. It is awkward for the “2nd” type of problem, finding Q when hf or Δp are known (see Ex. 6.9). Prepare a modified Moody chart whose abscissa is independent of Q and V, using ε/d as a parameter, from which one can immediately read the ordinate to find (dimensionless) Q or V. Use your chart to solve Example 6.9.