Note that Qr and Pr (Eqs. (8) and (10)) are a function of the
penstock properties and the gross head only. Dividing each side of
Eq. (6) by Pr (Eq. (10)) and defining P/Pr as Pþ and Q/Qr as Qþ, and
after some algebra, the following dimensionless relationship between power and discharge is obtained.