Open Channel Flow

The theoretical discharge over a broad-crested weir of width $b$ under head $H$ under critical flow conditions is given by:

Options:

• (A) $Q = \left(\frac{2}{3}\right)^{3/2} \sqrt{g} b H^{3/2} \approx 1.705 b H^{3/2}$
• (B) $Q = \frac{2}{3} b \sqrt{2g} H^{5/2}$
• (C) $Q = b H \sqrt{g H}$
• (D) $Q = 2.5 b H^{3/2}$