Volume Flow (\( Q_h \)):

\[ Q_h = 0.028 \times A \times D^{0.62} \]

Where:

• \( Q_h \) is the volume flow, in cubic meters per hour (m³/hr).
• \( A \) is the area of the orifice, in square centimeters (cm²).
• \( D \) is the hydraulic diameter, in centimeters (cm).