Condition for Maximum Discharge for a Given Value of Specific Energy

The specific energy $(E)$ at any section of a given channel is given by,

$$ \begin{aligned} \qquad E &=h+\frac{V^{2}}{2 g}, \\ &\text { where } V=\frac{Q}{A}=\frac{Q}{b \times h} \\ E &=h+\frac{Q^{2}}{b^{2} \times h^{2}} \times \frac{1}{2 g}\\ &=h+\frac{Q^{2}}{2 g b^{2} …