Airflow Resistance (\( \Delta P \)):

\[ \Delta P = \frac{a Q^2 L}{\log_e (1 + bQ)} \]

Where:

• \( \Delta P \) is the airflow resistance, in Pascals (Pa).
• \( L \) is the bed depth, in meters (m).
• \( a \) is a constant (2.57x10⁴ for rice; 2.104 for shelled corn).
• \( Q \) is the airflow, in cubic meters per second per square meter (m³/s-m²).
• \( b \) is a constant (13.2 for rice; 30.4 for shelled corn).