\large \[ D_{manifold} = \left( {\frac{{8Q_{manifold} ^2 }} {{gh_l \pi ^2 }}\frac{{1 + \left( {f\frac{{L_{manifold} }} {{D_{manifold} }} + \sum K } \right)\left( {\frac{1} {3} + \frac{1} {{2n}} + \frac{1} {{6n^2 }}} \right)}} {{1 - Q_{ratio} ^2 }}} \right)^{\frac{1} {4}} \] |