The optimal dimensionless head loss (hLþ ¼ hL/Hg) can be obtained
by assuming that the optimal upper limit for the flow
discharge is Qþ ¼
ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
7=ð30bÞ
p
(Eq. (17)). In Eq. (12), dividing the
second term of the right-hand side (RHS) by the first term of the
RHS gives