Bernoulli Equation (valid for incompressible fluids, no flid friction, no change in internal energy)
$$ E_t = \frac{p}{\rho} + \frac{v^2}{2} + zg $$
Ergun Equation
$$ \frac{\Delta p}{L} = \frac{1 – \varepsilon}{\varepsilon^3} \frac{G^2}{\phi D \rho} \left( \frac{150 (1 – \varepsilon) \mu }{\phi D G} + 1.75 \right)$$